4 ** The author disclaims copyright to this source code. In place of
5 ** a legal notice, here is a blessing:
7 ** May you do good and not evil.
8 ** May you find forgiveness for yourself and forgive others.
9 ** May you share freely, never taking more than you give.
11 *************************************************************************
12 ** This header file defines the interface that the SQLite library
13 ** presents to client programs. If a C-function, structure, datatype,
14 ** or constant definition does not appear in this file, then it is
15 ** not a published API of SQLite, is subject to change without
16 ** notice, and should not be referenced by programs that use SQLite.
18 ** Some of the definitions that are in this file are marked as
19 ** "experimental". Experimental interfaces are normally new
20 ** features recently added to SQLite. We do not anticipate changes
21 ** to experimental interfaces but reserve the right to make minor changes
22 ** if experience from use "in the wild" suggest such changes are prudent.
24 ** The official C-language API documentation for SQLite is derived
25 ** from comments in this file. This file is the authoritative source
26 ** on how SQLite interfaces are supposed to operate.
28 ** The name of this file under configuration management is "sqlite.h.in".
29 ** The makefile makes some minor changes to this file (such as inserting
30 ** the version number) and changes its name to "sqlite3.h" as
31 ** part of the build process.
35 #include <stdarg.h> /* Needed for the definition of va_list */
38 ** Make sure we can call this stuff from C++.
46 ** Facilitate override of interface linkage and calling conventions.
47 ** Be aware that these macros may not be used within this particular
48 ** translation of the amalgamation and its associated header file.
50 ** The SQLITE_EXTERN and SQLITE_API macros are used to instruct the
51 ** compiler that the target identifier should have external linkage.
53 ** The SQLITE_CDECL macro is used to set the calling convention for
54 ** public functions that accept a variable number of arguments.
56 ** The SQLITE_APICALL macro is used to set the calling convention for
57 ** public functions that accept a fixed number of arguments.
59 ** The SQLITE_STDCALL macro is no longer used and is now deprecated.
61 ** The SQLITE_CALLBACK macro is used to set the calling convention for
64 ** The SQLITE_SYSAPI macro is used to set the calling convention for
65 ** functions provided by the operating system.
67 ** Currently, the SQLITE_CDECL, SQLITE_APICALL, SQLITE_CALLBACK, and
68 ** SQLITE_SYSAPI macros are used only when building for environments
69 ** that require non-default calling conventions.
72 # define SQLITE_EXTERN extern
80 #ifndef SQLITE_APICALL
81 # define SQLITE_APICALL
83 #ifndef SQLITE_STDCALL
84 # define SQLITE_STDCALL SQLITE_APICALL
86 #ifndef SQLITE_CALLBACK
87 # define SQLITE_CALLBACK
90 # define SQLITE_SYSAPI
94 ** These no-op macros are used in front of interfaces to mark those
95 ** interfaces as either deprecated or experimental. New applications
96 ** should not use deprecated interfaces - they are supported for backwards
97 ** compatibility only. Application writers should be aware that
98 ** experimental interfaces are subject to change in point releases.
100 ** These macros used to resolve to various kinds of compiler magic that
101 ** would generate warning messages when they were used. But that
102 ** compiler magic ended up generating such a flurry of bug reports
103 ** that we have taken it all out and gone back to using simple
106 #define SQLITE_DEPRECATED
107 #define SQLITE_EXPERIMENTAL
110 ** Ensure these symbols were not defined by some previous header file.
112 #ifdef SQLITE_VERSION
113 # undef SQLITE_VERSION
115 #ifdef SQLITE_VERSION_NUMBER
116 # undef SQLITE_VERSION_NUMBER
120 ** CAPI3REF: Compile-Time Library Version Numbers
122 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
123 ** evaluates to a string literal that is the SQLite version in the
124 ** format "X.Y.Z" where X is the major version number (always 3 for
125 ** SQLite3) and Y is the minor version number and Z is the release number.)^
126 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
127 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
128 ** numbers used in [SQLITE_VERSION].)^
129 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
130 ** be larger than the release from which it is derived. Either Y will
131 ** be held constant and Z will be incremented or else Y will be incremented
132 ** and Z will be reset to zero.
134 ** Since [version 3.6.18] ([dateof:3.6.18]),
135 ** SQLite source code has been stored in the
136 ** <a href="http://www.fossil-scm.org/">Fossil configuration management
137 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to
138 ** a string which identifies a particular check-in of SQLite
139 ** within its configuration management system. ^The SQLITE_SOURCE_ID
140 ** string contains the date and time of the check-in (UTC) and a SHA1
141 ** or SHA3-256 hash of the entire source tree. If the source code has
142 ** been edited in any way since it was last checked in, then the last
143 ** four hexadecimal digits of the hash may be modified.
145 ** See also: [sqlite3_libversion()],
146 ** [sqlite3_libversion_number()], [sqlite3_sourceid()],
147 ** [sqlite_version()] and [sqlite_source_id()].
149 #define SQLITE_VERSION "3.45.0"
150 #define SQLITE_VERSION_NUMBER 3045000
151 #define SQLITE_SOURCE_ID "2024-01-15 17:01:13 1066602b2b1976fe58b5150777cced894af17c803e068f5918390d6915b46e1d"
154 ** CAPI3REF: Run-Time Library Version Numbers
155 ** KEYWORDS: sqlite3_version sqlite3_sourceid
157 ** These interfaces provide the same information as the [SQLITE_VERSION],
158 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
159 ** but are associated with the library instead of the header file. ^(Cautious
160 ** programmers might include assert() statements in their application to
161 ** verify that values returned by these interfaces match the macros in
162 ** the header, and thus ensure that the application is
163 ** compiled with matching library and header files.
166 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
167 ** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 );
168 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
169 ** </pre></blockquote>)^
171 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
172 ** macro. ^The sqlite3_libversion() function returns a pointer to the
173 ** to the sqlite3_version[] string constant. The sqlite3_libversion()
174 ** function is provided for use in DLLs since DLL users usually do not have
175 ** direct access to string constants within the DLL. ^The
176 ** sqlite3_libversion_number() function returns an integer equal to
177 ** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns
178 ** a pointer to a string constant whose value is the same as the
179 ** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built
180 ** using an edited copy of [the amalgamation], then the last four characters
181 ** of the hash might be different from [SQLITE_SOURCE_ID].)^
183 ** See also: [sqlite_version()] and [sqlite_source_id()].
185 SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
186 SQLITE_API const char *sqlite3_libversion(void);
187 SQLITE_API const char *sqlite3_sourceid(void);
188 SQLITE_API int sqlite3_libversion_number(void);
191 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics
193 ** ^The sqlite3_compileoption_used() function returns 0 or 1
194 ** indicating whether the specified option was defined at
195 ** compile time. ^The SQLITE_ prefix may be omitted from the
196 ** option name passed to sqlite3_compileoption_used().
198 ** ^The sqlite3_compileoption_get() function allows iterating
199 ** over the list of options that were defined at compile time by
200 ** returning the N-th compile time option string. ^If N is out of range,
201 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_
202 ** prefix is omitted from any strings returned by
203 ** sqlite3_compileoption_get().
205 ** ^Support for the diagnostic functions sqlite3_compileoption_used()
206 ** and sqlite3_compileoption_get() may be omitted by specifying the
207 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
209 ** See also: SQL functions [sqlite_compileoption_used()] and
210 ** [sqlite_compileoption_get()] and the [compile_options pragma].
212 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
213 SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
214 SQLITE_API const char *sqlite3_compileoption_get(int N);
216 # define sqlite3_compileoption_used(X) 0
217 # define sqlite3_compileoption_get(X) ((void*)0)
221 ** CAPI3REF: Test To See If The Library Is Threadsafe
223 ** ^The sqlite3_threadsafe() function returns zero if and only if
224 ** SQLite was compiled with mutexing code omitted due to the
225 ** [SQLITE_THREADSAFE] compile-time option being set to 0.
227 ** SQLite can be compiled with or without mutexes. When
228 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
229 ** are enabled and SQLite is threadsafe. When the
230 ** [SQLITE_THREADSAFE] macro is 0,
231 ** the mutexes are omitted. Without the mutexes, it is not safe
232 ** to use SQLite concurrently from more than one thread.
234 ** Enabling mutexes incurs a measurable performance penalty.
235 ** So if speed is of utmost importance, it makes sense to disable
236 ** the mutexes. But for maximum safety, mutexes should be enabled.
237 ** ^The default behavior is for mutexes to be enabled.
239 ** This interface can be used by an application to make sure that the
240 ** version of SQLite that it is linking against was compiled with
241 ** the desired setting of the [SQLITE_THREADSAFE] macro.
243 ** This interface only reports on the compile-time mutex setting
244 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
245 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
246 ** can be fully or partially disabled using a call to [sqlite3_config()]
247 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
248 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the
249 ** sqlite3_threadsafe() function shows only the compile-time setting of
250 ** thread safety, not any run-time changes to that setting made by
251 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
252 ** is unchanged by calls to sqlite3_config().)^
254 ** See the [threading mode] documentation for additional information.
256 SQLITE_API int sqlite3_threadsafe(void);
259 ** CAPI3REF: Database Connection Handle
260 ** KEYWORDS: {database connection} {database connections}
262 ** Each open SQLite database is represented by a pointer to an instance of
263 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3
264 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
265 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
266 ** and [sqlite3_close_v2()] are its destructors. There are many other
267 ** interfaces (such as
268 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
269 ** [sqlite3_busy_timeout()] to name but three) that are methods on an
272 typedef struct sqlite3 sqlite3;
275 ** CAPI3REF: 64-Bit Integer Types
276 ** KEYWORDS: sqlite_int64 sqlite_uint64
278 ** Because there is no cross-platform way to specify 64-bit integer types
279 ** SQLite includes typedefs for 64-bit signed and unsigned integers.
281 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
282 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards
283 ** compatibility only.
285 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values
286 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
287 ** sqlite3_uint64 and sqlite_uint64 types can store integer values
288 ** between 0 and +18446744073709551615 inclusive.
290 #ifdef SQLITE_INT64_TYPE
291 typedef SQLITE_INT64_TYPE sqlite_int64;
292 # ifdef SQLITE_UINT64_TYPE
293 typedef SQLITE_UINT64_TYPE sqlite_uint64;
295 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
297 #elif defined(_MSC_VER) || defined(__BORLANDC__)
298 typedef __int64 sqlite_int64;
299 typedef unsigned __int64 sqlite_uint64;
301 typedef long long int sqlite_int64;
302 typedef unsigned long long int sqlite_uint64;
304 typedef sqlite_int64 sqlite3_int64;
305 typedef sqlite_uint64 sqlite3_uint64;
308 ** If compiling for a processor that lacks floating point support,
309 ** substitute integer for floating-point.
311 #ifdef SQLITE_OMIT_FLOATING_POINT
312 # define double sqlite3_int64
316 ** CAPI3REF: Closing A Database Connection
317 ** DESTRUCTOR: sqlite3
319 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
320 ** for the [sqlite3] object.
321 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
322 ** the [sqlite3] object is successfully destroyed and all associated
323 ** resources are deallocated.
325 ** Ideally, applications should [sqlite3_finalize | finalize] all
326 ** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and
327 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
328 ** with the [sqlite3] object prior to attempting to close the object.
329 ** ^If the database connection is associated with unfinalized prepared
330 ** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then
331 ** sqlite3_close() will leave the database connection open and return
332 ** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared
333 ** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups,
334 ** it returns [SQLITE_OK] regardless, but instead of deallocating the database
335 ** connection immediately, it marks the database connection as an unusable
336 ** "zombie" and makes arrangements to automatically deallocate the database
337 ** connection after all prepared statements are finalized, all BLOB handles
338 ** are closed, and all backups have finished. The sqlite3_close_v2() interface
339 ** is intended for use with host languages that are garbage collected, and
340 ** where the order in which destructors are called is arbitrary.
342 ** ^If an [sqlite3] object is destroyed while a transaction is open,
343 ** the transaction is automatically rolled back.
345 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
346 ** must be either a NULL
347 ** pointer or an [sqlite3] object pointer obtained
348 ** from [sqlite3_open()], [sqlite3_open16()], or
349 ** [sqlite3_open_v2()], and not previously closed.
350 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
351 ** argument is a harmless no-op.
353 SQLITE_API int sqlite3_close(sqlite3*);
354 SQLITE_API int sqlite3_close_v2(sqlite3*);
357 ** The type for a callback function.
358 ** This is legacy and deprecated. It is included for historical
359 ** compatibility and is not documented.
361 typedef int (*sqlite3_callback)(void*,int,char**, char**);
364 ** CAPI3REF: One-Step Query Execution Interface
367 ** The sqlite3_exec() interface is a convenience wrapper around
368 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
369 ** that allows an application to run multiple statements of SQL
370 ** without having to use a lot of C code.
372 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
373 ** semicolon-separate SQL statements passed into its 2nd argument,
374 ** in the context of the [database connection] passed in as its 1st
375 ** argument. ^If the callback function of the 3rd argument to
376 ** sqlite3_exec() is not NULL, then it is invoked for each result row
377 ** coming out of the evaluated SQL statements. ^The 4th argument to
378 ** sqlite3_exec() is relayed through to the 1st argument of each
379 ** callback invocation. ^If the callback pointer to sqlite3_exec()
380 ** is NULL, then no callback is ever invoked and result rows are
383 ** ^If an error occurs while evaluating the SQL statements passed into
384 ** sqlite3_exec(), then execution of the current statement stops and
385 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
386 ** is not NULL then any error message is written into memory obtained
387 ** from [sqlite3_malloc()] and passed back through the 5th parameter.
388 ** To avoid memory leaks, the application should invoke [sqlite3_free()]
389 ** on error message strings returned through the 5th parameter of
390 ** sqlite3_exec() after the error message string is no longer needed.
391 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
392 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
393 ** NULL before returning.
395 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
396 ** routine returns SQLITE_ABORT without invoking the callback again and
397 ** without running any subsequent SQL statements.
399 ** ^The 2nd argument to the sqlite3_exec() callback function is the
400 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
401 ** callback is an array of pointers to strings obtained as if from
402 ** [sqlite3_column_text()], one for each column. ^If an element of a
403 ** result row is NULL then the corresponding string pointer for the
404 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
405 ** sqlite3_exec() callback is an array of pointers to strings where each
406 ** entry represents the name of corresponding result column as obtained
407 ** from [sqlite3_column_name()].
409 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
410 ** to an empty string, or a pointer that contains only whitespace and/or
411 ** SQL comments, then no SQL statements are evaluated and the database
417 ** <li> The application must ensure that the 1st parameter to sqlite3_exec()
418 ** is a valid and open [database connection].
419 ** <li> The application must not close the [database connection] specified by
420 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
421 ** <li> The application must not modify the SQL statement text passed into
422 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
425 SQLITE_API int sqlite3_exec(
426 sqlite3*, /* An open database */
427 const char *sql, /* SQL to be evaluated */
428 int (*callback)(void*,int,char**,char**), /* Callback function */
429 void *, /* 1st argument to callback */
430 char **errmsg /* Error msg written here */
434 ** CAPI3REF: Result Codes
435 ** KEYWORDS: {result code definitions}
437 ** Many SQLite functions return an integer result code from the set shown
438 ** here in order to indicate success or failure.
440 ** New error codes may be added in future versions of SQLite.
442 ** See also: [extended result code definitions]
444 #define SQLITE_OK 0 /* Successful result */
445 /* beginning-of-error-codes */
446 #define SQLITE_ERROR 1 /* Generic error */
447 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
448 #define SQLITE_PERM 3 /* Access permission denied */
449 #define SQLITE_ABORT 4 /* Callback routine requested an abort */
450 #define SQLITE_BUSY 5 /* The database file is locked */
451 #define SQLITE_LOCKED 6 /* A table in the database is locked */
452 #define SQLITE_NOMEM 7 /* A malloc() failed */
453 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */
454 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
455 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
456 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */
457 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */
458 #define SQLITE_FULL 13 /* Insertion failed because database is full */
459 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */
460 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */
461 #define SQLITE_EMPTY 16 /* Internal use only */
462 #define SQLITE_SCHEMA 17 /* The database schema changed */
463 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
464 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
465 #define SQLITE_MISMATCH 20 /* Data type mismatch */
466 #define SQLITE_MISUSE 21 /* Library used incorrectly */
467 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
468 #define SQLITE_AUTH 23 /* Authorization denied */
469 #define SQLITE_FORMAT 24 /* Not used */
470 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
471 #define SQLITE_NOTADB 26 /* File opened that is not a database file */
472 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */
473 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */
474 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
475 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
476 /* end-of-error-codes */
479 ** CAPI3REF: Extended Result Codes
480 ** KEYWORDS: {extended result code definitions}
482 ** In its default configuration, SQLite API routines return one of 30 integer
483 ** [result codes]. However, experience has shown that many of
484 ** these result codes are too coarse-grained. They do not provide as
485 ** much information about problems as programmers might like. In an effort to
486 ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8]
487 ** and later) include
488 ** support for additional result codes that provide more detailed information
489 ** about errors. These [extended result codes] are enabled or disabled
490 ** on a per database connection basis using the
491 ** [sqlite3_extended_result_codes()] API. Or, the extended code for
492 ** the most recent error can be obtained using
493 ** [sqlite3_extended_errcode()].
495 #define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8))
496 #define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8))
497 #define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8))
498 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
499 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
500 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
501 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
502 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
503 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
504 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
505 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
506 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
507 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
508 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
509 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
510 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
511 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
512 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
513 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8))
514 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8))
515 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8))
516 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8))
517 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8))
518 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8))
519 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8))
520 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8))
521 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8))
522 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8))
523 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8))
524 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8))
525 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8))
526 #define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8))
527 #define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8))
528 #define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8))
529 #define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8))
530 #define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8))
531 #define SQLITE_IOERR_IN_PAGE (SQLITE_IOERR | (34<<8))
532 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8))
533 #define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8))
534 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8))
535 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8))
536 #define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8))
537 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8))
538 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8))
539 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8))
540 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8))
541 #define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */
542 #define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8))
543 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8))
544 #define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8))
545 #define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8))
546 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8))
547 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8))
548 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8))
549 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8))
550 #define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8))
551 #define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8))
552 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8))
553 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8))
554 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8))
555 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8))
556 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8))
557 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8))
558 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8))
559 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8))
560 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8))
561 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8))
562 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8))
563 #define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8))
564 #define SQLITE_CONSTRAINT_DATATYPE (SQLITE_CONSTRAINT |(12<<8))
565 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8))
566 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
567 #define SQLITE_NOTICE_RBU (SQLITE_NOTICE | (3<<8))
568 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8))
569 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8))
570 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8))
571 #define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) /* internal use only */
574 ** CAPI3REF: Flags For File Open Operations
576 ** These bit values are intended for use in the
577 ** 3rd parameter to the [sqlite3_open_v2()] interface and
578 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
580 ** Only those flags marked as "Ok for sqlite3_open_v2()" may be
581 ** used as the third argument to the [sqlite3_open_v2()] interface.
582 ** The other flags have historically been ignored by sqlite3_open_v2(),
583 ** though future versions of SQLite might change so that an error is
584 ** raised if any of the disallowed bits are passed into sqlite3_open_v2().
585 ** Applications should not depend on the historical behavior.
587 ** Note in particular that passing the SQLITE_OPEN_EXCLUSIVE flag into
588 ** [sqlite3_open_v2()] does *not* cause the underlying database file
589 ** to be opened using O_EXCL. Passing SQLITE_OPEN_EXCLUSIVE into
590 ** [sqlite3_open_v2()] has historically be a no-op and might become an
591 ** error in future versions of SQLite.
593 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
594 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
595 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
596 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
597 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
598 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */
599 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */
600 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */
601 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
602 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
603 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
604 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
605 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
606 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
607 #define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */
608 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
609 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
610 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
611 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
612 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */
613 #define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */
614 #define SQLITE_OPEN_EXRESCODE 0x02000000 /* Extended result codes */
616 /* Reserved: 0x00F00000 */
617 /* Legacy compatibility: */
618 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
622 ** CAPI3REF: Device Characteristics
624 ** The xDeviceCharacteristics method of the [sqlite3_io_methods]
625 ** object returns an integer which is a vector of these
626 ** bit values expressing I/O characteristics of the mass storage
627 ** device that holds the file that the [sqlite3_io_methods]
630 ** The SQLITE_IOCAP_ATOMIC property means that all writes of
631 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
632 ** mean that writes of blocks that are nnn bytes in size and
633 ** are aligned to an address which is an integer multiple of
634 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
635 ** that when data is appended to a file, the data is appended
636 ** first then the size of the file is extended, never the other
637 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
638 ** information is written to disk in the same order as calls
639 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
640 ** after reboot following a crash or power loss, the only bytes in a
641 ** file that were written at the application level might have changed
642 ** and that adjacent bytes, even bytes within the same sector are
643 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
644 ** flag indicates that a file cannot be deleted when open. The
645 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
646 ** read-only media and cannot be changed even by processes with
647 ** elevated privileges.
649 ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying
650 ** filesystem supports doing multiple write operations atomically when those
651 ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and
652 ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE].
654 #define SQLITE_IOCAP_ATOMIC 0x00000001
655 #define SQLITE_IOCAP_ATOMIC512 0x00000002
656 #define SQLITE_IOCAP_ATOMIC1K 0x00000004
657 #define SQLITE_IOCAP_ATOMIC2K 0x00000008
658 #define SQLITE_IOCAP_ATOMIC4K 0x00000010
659 #define SQLITE_IOCAP_ATOMIC8K 0x00000020
660 #define SQLITE_IOCAP_ATOMIC16K 0x00000040
661 #define SQLITE_IOCAP_ATOMIC32K 0x00000080
662 #define SQLITE_IOCAP_ATOMIC64K 0x00000100
663 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200
664 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400
665 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800
666 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000
667 #define SQLITE_IOCAP_IMMUTABLE 0x00002000
668 #define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000
671 ** CAPI3REF: File Locking Levels
673 ** SQLite uses one of these integer values as the second
674 ** argument to calls it makes to the xLock() and xUnlock() methods
675 ** of an [sqlite3_io_methods] object. These values are ordered from
676 ** lest restrictive to most restrictive.
678 ** The argument to xLock() is always SHARED or higher. The argument to
679 ** xUnlock is either SHARED or NONE.
681 #define SQLITE_LOCK_NONE 0 /* xUnlock() only */
682 #define SQLITE_LOCK_SHARED 1 /* xLock() or xUnlock() */
683 #define SQLITE_LOCK_RESERVED 2 /* xLock() only */
684 #define SQLITE_LOCK_PENDING 3 /* xLock() only */
685 #define SQLITE_LOCK_EXCLUSIVE 4 /* xLock() only */
688 ** CAPI3REF: Synchronization Type Flags
690 ** When SQLite invokes the xSync() method of an
691 ** [sqlite3_io_methods] object it uses a combination of
692 ** these integer values as the second argument.
694 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
695 ** sync operation only needs to flush data to mass storage. Inode
696 ** information need not be flushed. If the lower four bits of the flag
697 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
698 ** If the lower four bits equal SQLITE_SYNC_FULL, that means
699 ** to use Mac OS X style fullsync instead of fsync().
701 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
702 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
703 ** settings. The [synchronous pragma] determines when calls to the
704 ** xSync VFS method occur and applies uniformly across all platforms.
705 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
706 ** energetic or rigorous or forceful the sync operations are and
707 ** only make a difference on Mac OSX for the default SQLite code.
708 ** (Third-party VFS implementations might also make the distinction
709 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
710 ** operating systems natively supported by SQLite, only Mac OSX
711 ** cares about the difference.)
713 #define SQLITE_SYNC_NORMAL 0x00002
714 #define SQLITE_SYNC_FULL 0x00003
715 #define SQLITE_SYNC_DATAONLY 0x00010
718 ** CAPI3REF: OS Interface Open File Handle
720 ** An [sqlite3_file] object represents an open file in the
721 ** [sqlite3_vfs | OS interface layer]. Individual OS interface
722 ** implementations will
723 ** want to subclass this object by appending additional fields
724 ** for their own use. The pMethods entry is a pointer to an
725 ** [sqlite3_io_methods] object that defines methods for performing
726 ** I/O operations on the open file.
728 typedef struct sqlite3_file sqlite3_file;
729 struct sqlite3_file {
730 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
734 ** CAPI3REF: OS Interface File Virtual Methods Object
736 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an
737 ** [sqlite3_file] object (or, more commonly, a subclass of the
738 ** [sqlite3_file] object) with a pointer to an instance of this object.
739 ** This object defines the methods used to perform various operations
740 ** against the open file represented by the [sqlite3_file] object.
742 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
743 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
744 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
745 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
746 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
749 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
750 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
751 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
752 ** flag may be ORed in to indicate that only the data of the file
753 ** and not its inode needs to be synced.
755 ** The integer values to xLock() and xUnlock() are one of
757 ** <li> [SQLITE_LOCK_NONE],
758 ** <li> [SQLITE_LOCK_SHARED],
759 ** <li> [SQLITE_LOCK_RESERVED],
760 ** <li> [SQLITE_LOCK_PENDING], or
761 ** <li> [SQLITE_LOCK_EXCLUSIVE].
763 ** xLock() upgrades the database file lock. In other words, xLock() moves the
764 ** database file lock in the direction NONE toward EXCLUSIVE. The argument to
765 ** xLock() is always on of SHARED, RESERVED, PENDING, or EXCLUSIVE, never
766 ** SQLITE_LOCK_NONE. If the database file lock is already at or above the
767 ** requested lock, then the call to xLock() is a no-op.
768 ** xUnlock() downgrades the database file lock to either SHARED or NONE.
769 * If the lock is already at or below the requested lock state, then the call
770 ** to xUnlock() is a no-op.
771 ** The xCheckReservedLock() method checks whether any database connection,
772 ** either in this process or in some other process, is holding a RESERVED,
773 ** PENDING, or EXCLUSIVE lock on the file. It returns true
774 ** if such a lock exists and false otherwise.
776 ** The xFileControl() method is a generic interface that allows custom
777 ** VFS implementations to directly control an open file using the
778 ** [sqlite3_file_control()] interface. The second "op" argument is an
779 ** integer opcode. The third argument is a generic pointer intended to
780 ** point to a structure that may contain arguments or space in which to
781 ** write return values. Potential uses for xFileControl() might be
782 ** functions to enable blocking locks with timeouts, to change the
783 ** locking strategy (for example to use dot-file locks), to inquire
784 ** about the status of a lock, or to break stale locks. The SQLite
785 ** core reserves all opcodes less than 100 for its own use.
786 ** A [file control opcodes | list of opcodes] less than 100 is available.
787 ** Applications that define a custom xFileControl method should use opcodes
788 ** greater than 100 to avoid conflicts. VFS implementations should
789 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not
792 ** The xSectorSize() method returns the sector size of the
793 ** device that underlies the file. The sector size is the
794 ** minimum write that can be performed without disturbing
795 ** other bytes in the file. The xDeviceCharacteristics()
796 ** method returns a bit vector describing behaviors of the
797 ** underlying device:
800 ** <li> [SQLITE_IOCAP_ATOMIC]
801 ** <li> [SQLITE_IOCAP_ATOMIC512]
802 ** <li> [SQLITE_IOCAP_ATOMIC1K]
803 ** <li> [SQLITE_IOCAP_ATOMIC2K]
804 ** <li> [SQLITE_IOCAP_ATOMIC4K]
805 ** <li> [SQLITE_IOCAP_ATOMIC8K]
806 ** <li> [SQLITE_IOCAP_ATOMIC16K]
807 ** <li> [SQLITE_IOCAP_ATOMIC32K]
808 ** <li> [SQLITE_IOCAP_ATOMIC64K]
809 ** <li> [SQLITE_IOCAP_SAFE_APPEND]
810 ** <li> [SQLITE_IOCAP_SEQUENTIAL]
811 ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN]
812 ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE]
813 ** <li> [SQLITE_IOCAP_IMMUTABLE]
814 ** <li> [SQLITE_IOCAP_BATCH_ATOMIC]
817 ** The SQLITE_IOCAP_ATOMIC property means that all writes of
818 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
819 ** mean that writes of blocks that are nnn bytes in size and
820 ** are aligned to an address which is an integer multiple of
821 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
822 ** that when data is appended to a file, the data is appended
823 ** first then the size of the file is extended, never the other
824 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
825 ** information is written to disk in the same order as calls
828 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
829 ** in the unread portions of the buffer with zeros. A VFS that
830 ** fails to zero-fill short reads might seem to work. However,
831 ** failure to zero-fill short reads will eventually lead to
832 ** database corruption.
834 typedef struct sqlite3_io_methods sqlite3_io_methods;
835 struct sqlite3_io_methods {
837 int (*xClose)(sqlite3_file*);
838 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
839 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
840 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
841 int (*xSync)(sqlite3_file*, int flags);
842 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
843 int (*xLock)(sqlite3_file*, int);
844 int (*xUnlock)(sqlite3_file*, int);
845 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
846 int (*xFileControl)(sqlite3_file*, int op, void *pArg);
847 int (*xSectorSize)(sqlite3_file*);
848 int (*xDeviceCharacteristics)(sqlite3_file*);
849 /* Methods above are valid for version 1 */
850 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
851 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
852 void (*xShmBarrier)(sqlite3_file*);
853 int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
854 /* Methods above are valid for version 2 */
855 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
856 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
857 /* Methods above are valid for version 3 */
858 /* Additional methods may be added in future releases */
862 ** CAPI3REF: Standard File Control Opcodes
863 ** KEYWORDS: {file control opcodes} {file control opcode}
865 ** These integer constants are opcodes for the xFileControl method
866 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
870 ** <li>[[SQLITE_FCNTL_LOCKSTATE]]
871 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
872 ** opcode causes the xFileControl method to write the current state of
873 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
874 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
875 ** into an integer that the pArg argument points to.
876 ** This capability is only available if SQLite is compiled with [SQLITE_DEBUG].
878 ** <li>[[SQLITE_FCNTL_SIZE_HINT]]
879 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
880 ** layer a hint of how large the database file will grow to be during the
881 ** current transaction. This hint is not guaranteed to be accurate but it
882 ** is often close. The underlying VFS might choose to preallocate database
883 ** file space based on this hint in order to help writes to the database
886 ** <li>[[SQLITE_FCNTL_SIZE_LIMIT]]
887 ** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that
888 ** implements [sqlite3_deserialize()] to set an upper bound on the size
889 ** of the in-memory database. The argument is a pointer to a [sqlite3_int64].
890 ** If the integer pointed to is negative, then it is filled in with the
891 ** current limit. Otherwise the limit is set to the larger of the value
892 ** of the integer pointed to and the current database size. The integer
893 ** pointed to is set to the new limit.
895 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
896 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
897 ** extends and truncates the database file in chunks of a size specified
898 ** by the user. The fourth argument to [sqlite3_file_control()] should
899 ** point to an integer (type int) containing the new chunk-size to use
900 ** for the nominated database. Allocating database file space in large
901 ** chunks (say 1MB at a time), may reduce file-system fragmentation and
902 ** improve performance on some systems.
904 ** <li>[[SQLITE_FCNTL_FILE_POINTER]]
905 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
906 ** to the [sqlite3_file] object associated with a particular database
907 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER].
909 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]
910 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
911 ** to the [sqlite3_file] object associated with the journal file (either
912 ** the [rollback journal] or the [write-ahead log]) for a particular database
913 ** connection. See also [SQLITE_FCNTL_FILE_POINTER].
915 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
918 ** <li>[[SQLITE_FCNTL_SYNC]]
919 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
920 ** sent to the VFS immediately before the xSync method is invoked on a
921 ** database file descriptor. Or, if the xSync method is not invoked
922 ** because the user has configured SQLite with
923 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
924 ** of the xSync method. In most cases, the pointer argument passed with
925 ** this file-control is NULL. However, if the database file is being synced
926 ** as part of a multi-database commit, the argument points to a nul-terminated
927 ** string containing the transactions super-journal file name. VFSes that
928 ** do not need this signal should silently ignore this opcode. Applications
929 ** should not call [sqlite3_file_control()] with this opcode as doing so may
930 ** disrupt the operation of the specialized VFSes that do require it.
932 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
933 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
934 ** and sent to the VFS after a transaction has been committed immediately
935 ** but before the database is unlocked. VFSes that do not need this signal
936 ** should silently ignore this opcode. Applications should not call
937 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the
938 ** operation of the specialized VFSes that do require it.
940 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
941 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
942 ** retry counts and intervals for certain disk I/O operations for the
943 ** windows [VFS] in order to provide robustness in the presence of
944 ** anti-virus programs. By default, the windows VFS will retry file read,
945 ** file write, and file delete operations up to 10 times, with a delay
946 ** of 25 milliseconds before the first retry and with the delay increasing
947 ** by an additional 25 milliseconds with each subsequent retry. This
948 ** opcode allows these two values (10 retries and 25 milliseconds of delay)
949 ** to be adjusted. The values are changed for all database connections
950 ** within the same process. The argument is a pointer to an array of two
951 ** integers where the first integer is the new retry count and the second
952 ** integer is the delay. If either integer is negative, then the setting
953 ** is not changed but instead the prior value of that setting is written
954 ** into the array entry, allowing the current retry settings to be
955 ** interrogated. The zDbName parameter is ignored.
957 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
958 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
959 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary
960 ** write ahead log ([WAL file]) and shared memory
961 ** files used for transaction control
962 ** are automatically deleted when the latest connection to the database
963 ** closes. Setting persistent WAL mode causes those files to persist after
964 ** close. Persisting the files is useful when other processes that do not
965 ** have write permission on the directory containing the database file want
966 ** to read the database file, as the WAL and shared memory files must exist
967 ** in order for the database to be readable. The fourth parameter to
968 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
969 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
970 ** WAL mode. If the integer is -1, then it is overwritten with the current
971 ** WAL persistence setting.
973 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
974 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
975 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
976 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
977 ** xDeviceCharacteristics methods. The fourth parameter to
978 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
979 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
980 ** mode. If the integer is -1, then it is overwritten with the current
981 ** zero-damage mode setting.
983 ** <li>[[SQLITE_FCNTL_OVERWRITE]]
984 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
985 ** a write transaction to indicate that, unless it is rolled back for some
986 ** reason, the entire database file will be overwritten by the current
987 ** transaction. This is used by VACUUM operations.
989 ** <li>[[SQLITE_FCNTL_VFSNAME]]
990 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
991 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the
992 ** final bottom-level VFS are written into memory obtained from
993 ** [sqlite3_malloc()] and the result is stored in the char* variable
994 ** that the fourth parameter of [sqlite3_file_control()] points to.
995 ** The caller is responsible for freeing the memory when done. As with
996 ** all file-control actions, there is no guarantee that this will actually
997 ** do anything. Callers should initialize the char* variable to a NULL
998 ** pointer in case this file-control is not implemented. This file-control
999 ** is intended for diagnostic use only.
1001 ** <li>[[SQLITE_FCNTL_VFS_POINTER]]
1002 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
1003 ** [VFSes] currently in use. ^(The argument X in
1004 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
1005 ** of type "[sqlite3_vfs] **". This opcodes will set *X
1006 ** to a pointer to the top-level VFS.)^
1007 ** ^When there are multiple VFS shims in the stack, this opcode finds the
1008 ** upper-most shim only.
1010 ** <li>[[SQLITE_FCNTL_PRAGMA]]
1011 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
1012 ** file control is sent to the open [sqlite3_file] object corresponding
1013 ** to the database file to which the pragma statement refers. ^The argument
1014 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
1015 ** pointers to strings (char**) in which the second element of the array
1016 ** is the name of the pragma and the third element is the argument to the
1017 ** pragma or NULL if the pragma has no argument. ^The handler for an
1018 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
1019 ** of the char** argument point to a string obtained from [sqlite3_mprintf()]
1020 ** or the equivalent and that string will become the result of the pragma or
1021 ** the error message if the pragma fails. ^If the
1022 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
1023 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA]
1024 ** file control returns [SQLITE_OK], then the parser assumes that the
1025 ** VFS has handled the PRAGMA itself and the parser generates a no-op
1026 ** prepared statement if result string is NULL, or that returns a copy
1027 ** of the result string if the string is non-NULL.
1028 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
1029 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
1030 ** that the VFS encountered an error while handling the [PRAGMA] and the
1031 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA]
1032 ** file control occurs at the beginning of pragma statement analysis and so
1033 ** it is able to override built-in [PRAGMA] statements.
1035 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
1036 ** ^The [SQLITE_FCNTL_BUSYHANDLER]
1037 ** file-control may be invoked by SQLite on the database file handle
1038 ** shortly after it is opened in order to provide a custom VFS with access
1039 ** to the connection's busy-handler callback. The argument is of type (void**)
1040 ** - an array of two (void *) values. The first (void *) actually points
1041 ** to a function of type (int (*)(void *)). In order to invoke the connection's
1042 ** busy-handler, this function should be invoked with the second (void *) in
1043 ** the array as the only argument. If it returns non-zero, then the operation
1044 ** should be retried. If it returns zero, the custom VFS should abandon the
1045 ** current operation.
1047 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
1048 ** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
1049 ** to have SQLite generate a
1050 ** temporary filename using the same algorithm that is followed to generate
1051 ** temporary filenames for TEMP tables and other internal uses. The
1052 ** argument should be a char** which will be filled with the filename
1053 ** written into memory obtained from [sqlite3_malloc()]. The caller should
1054 ** invoke [sqlite3_free()] on the result to avoid a memory leak.
1056 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
1057 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
1058 ** maximum number of bytes that will be used for memory-mapped I/O.
1059 ** The argument is a pointer to a value of type sqlite3_int64 that
1060 ** is an advisory maximum number of bytes in the file to memory map. The
1061 ** pointer is overwritten with the old value. The limit is not changed if
1062 ** the value originally pointed to is negative, and so the current limit
1063 ** can be queried by passing in a pointer to a negative number. This
1064 ** file-control is used internally to implement [PRAGMA mmap_size].
1066 ** <li>[[SQLITE_FCNTL_TRACE]]
1067 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information
1068 ** to the VFS about what the higher layers of the SQLite stack are doing.
1069 ** This file control is used by some VFS activity tracing [shims].
1070 ** The argument is a zero-terminated string. Higher layers in the
1071 ** SQLite stack may generate instances of this file control if
1072 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
1074 ** <li>[[SQLITE_FCNTL_HAS_MOVED]]
1075 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
1076 ** pointer to an integer and it writes a boolean into that integer depending
1077 ** on whether or not the file has been renamed, moved, or deleted since it
1078 ** was first opened.
1080 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]]
1081 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the
1082 ** underlying native file handle associated with a file handle. This file
1083 ** control interprets its argument as a pointer to a native file handle and
1084 ** writes the resulting value there.
1086 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
1087 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This
1088 ** opcode causes the xFileControl method to swap the file handle with the one
1089 ** pointed to by the pArg argument. This capability is used during testing
1090 ** and only needs to be supported when SQLITE_TEST is defined.
1092 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
1093 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
1094 ** be advantageous to block on the next WAL lock if the lock is not immediately
1095 ** available. The WAL subsystem issues this signal during rare
1096 ** circumstances in order to fix a problem with priority inversion.
1097 ** Applications should <em>not</em> use this file-control.
1099 ** <li>[[SQLITE_FCNTL_ZIPVFS]]
1100 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
1101 ** VFS should return SQLITE_NOTFOUND for this opcode.
1103 ** <li>[[SQLITE_FCNTL_RBU]]
1104 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
1105 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for
1108 ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]]
1109 ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then
1110 ** the file descriptor is placed in "batch write mode", which
1111 ** means all subsequent write operations will be deferred and done
1112 ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems
1113 ** that do not support batch atomic writes will return SQLITE_NOTFOUND.
1114 ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to
1115 ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or
1116 ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make
1117 ** no VFS interface calls on the same [sqlite3_file] file descriptor
1118 ** except for calls to the xWrite method and the xFileControl method
1119 ** with [SQLITE_FCNTL_SIZE_HINT].
1121 ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]]
1122 ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write
1123 ** operations since the previous successful call to
1124 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically.
1125 ** This file control returns [SQLITE_OK] if and only if the writes were
1126 ** all performed successfully and have been committed to persistent storage.
1127 ** ^Regardless of whether or not it is successful, this file control takes
1128 ** the file descriptor out of batch write mode so that all subsequent
1129 ** write operations are independent.
1130 ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without
1131 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1133 ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]]
1134 ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write
1135 ** operations since the previous successful call to
1136 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back.
1137 ** ^This file control takes the file descriptor out of batch write mode
1138 ** so that all subsequent write operations are independent.
1139 ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without
1140 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1142 ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]]
1143 ** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS
1144 ** to block for up to M milliseconds before failing when attempting to
1145 ** obtain a file lock using the xLock or xShmLock methods of the VFS.
1146 ** The parameter is a pointer to a 32-bit signed integer that contains
1147 ** the value that M is to be set to. Before returning, the 32-bit signed
1148 ** integer is overwritten with the previous value of M.
1150 ** <li>[[SQLITE_FCNTL_DATA_VERSION]]
1151 ** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to
1152 ** a database file. The argument is a pointer to a 32-bit unsigned integer.
1153 ** The "data version" for the pager is written into the pointer. The
1154 ** "data version" changes whenever any change occurs to the corresponding
1155 ** database file, either through SQL statements on the same database
1156 ** connection or through transactions committed by separate database
1157 ** connections possibly in other processes. The [sqlite3_total_changes()]
1158 ** interface can be used to find if any database on the connection has changed,
1159 ** but that interface responds to changes on TEMP as well as MAIN and does
1160 ** not provide a mechanism to detect changes to MAIN only. Also, the
1161 ** [sqlite3_total_changes()] interface responds to internal changes only and
1162 ** omits changes made by other database connections. The
1163 ** [PRAGMA data_version] command provides a mechanism to detect changes to
1164 ** a single attached database that occur due to other database connections,
1165 ** but omits changes implemented by the database connection on which it is
1166 ** called. This file control is the only mechanism to detect changes that
1167 ** happen either internally or externally and that are associated with
1168 ** a particular attached database.
1170 ** <li>[[SQLITE_FCNTL_CKPT_START]]
1171 ** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint
1172 ** in wal mode before the client starts to copy pages from the wal
1173 ** file to the database file.
1175 ** <li>[[SQLITE_FCNTL_CKPT_DONE]]
1176 ** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint
1177 ** in wal mode after the client has finished copying pages from the wal
1178 ** file to the database file, but before the *-shm file is updated to
1179 ** record the fact that the pages have been checkpointed.
1181 ** <li>[[SQLITE_FCNTL_EXTERNAL_READER]]
1182 ** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect
1183 ** whether or not there is a database client in another process with a wal-mode
1184 ** transaction open on the database or not. It is only available on unix.The
1185 ** (void*) argument passed with this file-control should be a pointer to a
1186 ** value of type (int). The integer value is set to 1 if the database is a wal
1187 ** mode database and there exists at least one client in another process that
1188 ** currently has an SQL transaction open on the database. It is set to 0 if
1189 ** the database is not a wal-mode db, or if there is no such connection in any
1190 ** other process. This opcode cannot be used to detect transactions opened
1191 ** by clients within the current process, only within other processes.
1193 ** <li>[[SQLITE_FCNTL_CKSM_FILE]]
1194 ** The [SQLITE_FCNTL_CKSM_FILE] opcode is for use internally by the
1195 ** [checksum VFS shim] only.
1197 ** <li>[[SQLITE_FCNTL_RESET_CACHE]]
1198 ** If there is currently no transaction open on the database, and the
1199 ** database is not a temp db, then the [SQLITE_FCNTL_RESET_CACHE] file-control
1200 ** purges the contents of the in-memory page cache. If there is an open
1201 ** transaction, or if the db is a temp-db, this opcode is a no-op, not an error.
1204 #define SQLITE_FCNTL_LOCKSTATE 1
1205 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2
1206 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3
1207 #define SQLITE_FCNTL_LAST_ERRNO 4
1208 #define SQLITE_FCNTL_SIZE_HINT 5
1209 #define SQLITE_FCNTL_CHUNK_SIZE 6
1210 #define SQLITE_FCNTL_FILE_POINTER 7
1211 #define SQLITE_FCNTL_SYNC_OMITTED 8
1212 #define SQLITE_FCNTL_WIN32_AV_RETRY 9
1213 #define SQLITE_FCNTL_PERSIST_WAL 10
1214 #define SQLITE_FCNTL_OVERWRITE 11
1215 #define SQLITE_FCNTL_VFSNAME 12
1216 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13
1217 #define SQLITE_FCNTL_PRAGMA 14
1218 #define SQLITE_FCNTL_BUSYHANDLER 15
1219 #define SQLITE_FCNTL_TEMPFILENAME 16
1220 #define SQLITE_FCNTL_MMAP_SIZE 18
1221 #define SQLITE_FCNTL_TRACE 19
1222 #define SQLITE_FCNTL_HAS_MOVED 20
1223 #define SQLITE_FCNTL_SYNC 21
1224 #define SQLITE_FCNTL_COMMIT_PHASETWO 22
1225 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23
1226 #define SQLITE_FCNTL_WAL_BLOCK 24
1227 #define SQLITE_FCNTL_ZIPVFS 25
1228 #define SQLITE_FCNTL_RBU 26
1229 #define SQLITE_FCNTL_VFS_POINTER 27
1230 #define SQLITE_FCNTL_JOURNAL_POINTER 28
1231 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29
1232 #define SQLITE_FCNTL_PDB 30
1233 #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31
1234 #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32
1235 #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33
1236 #define SQLITE_FCNTL_LOCK_TIMEOUT 34
1237 #define SQLITE_FCNTL_DATA_VERSION 35
1238 #define SQLITE_FCNTL_SIZE_LIMIT 36
1239 #define SQLITE_FCNTL_CKPT_DONE 37
1240 #define SQLITE_FCNTL_RESERVE_BYTES 38
1241 #define SQLITE_FCNTL_CKPT_START 39
1242 #define SQLITE_FCNTL_EXTERNAL_READER 40
1243 #define SQLITE_FCNTL_CKSM_FILE 41
1244 #define SQLITE_FCNTL_RESET_CACHE 42
1246 /* deprecated names */
1247 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE
1248 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE
1249 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO
1253 ** CAPI3REF: Mutex Handle
1255 ** The mutex module within SQLite defines [sqlite3_mutex] to be an
1256 ** abstract type for a mutex object. The SQLite core never looks
1257 ** at the internal representation of an [sqlite3_mutex]. It only
1258 ** deals with pointers to the [sqlite3_mutex] object.
1260 ** Mutexes are created using [sqlite3_mutex_alloc()].
1262 typedef struct sqlite3_mutex sqlite3_mutex;
1265 ** CAPI3REF: Loadable Extension Thunk
1267 ** A pointer to the opaque sqlite3_api_routines structure is passed as
1268 ** the third parameter to entry points of [loadable extensions]. This
1269 ** structure must be typedefed in order to work around compiler warnings
1270 ** on some platforms.
1272 typedef struct sqlite3_api_routines sqlite3_api_routines;
1275 ** CAPI3REF: File Name
1277 ** Type [sqlite3_filename] is used by SQLite to pass filenames to the
1278 ** xOpen method of a [VFS]. It may be cast to (const char*) and treated
1279 ** as a normal, nul-terminated, UTF-8 buffer containing the filename, but
1280 ** may also be passed to special APIs such as:
1283 ** <li> sqlite3_filename_database()
1284 ** <li> sqlite3_filename_journal()
1285 ** <li> sqlite3_filename_wal()
1286 ** <li> sqlite3_uri_parameter()
1287 ** <li> sqlite3_uri_boolean()
1288 ** <li> sqlite3_uri_int64()
1289 ** <li> sqlite3_uri_key()
1292 typedef const char *sqlite3_filename;
1295 ** CAPI3REF: OS Interface Object
1297 ** An instance of the sqlite3_vfs object defines the interface between
1298 ** the SQLite core and the underlying operating system. The "vfs"
1299 ** in the name of the object stands for "virtual file system". See
1300 ** the [VFS | VFS documentation] for further information.
1302 ** The VFS interface is sometimes extended by adding new methods onto
1303 ** the end. Each time such an extension occurs, the iVersion field
1304 ** is incremented. The iVersion value started out as 1 in
1305 ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2
1306 ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased
1307 ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields
1308 ** may be appended to the sqlite3_vfs object and the iVersion value
1309 ** may increase again in future versions of SQLite.
1310 ** Note that due to an oversight, the structure
1311 ** of the sqlite3_vfs object changed in the transition from
1312 ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0]
1313 ** and yet the iVersion field was not increased.
1315 ** The szOsFile field is the size of the subclassed [sqlite3_file]
1316 ** structure used by this VFS. mxPathname is the maximum length of
1317 ** a pathname in this VFS.
1319 ** Registered sqlite3_vfs objects are kept on a linked list formed by
1320 ** the pNext pointer. The [sqlite3_vfs_register()]
1321 ** and [sqlite3_vfs_unregister()] interfaces manage this list
1322 ** in a thread-safe way. The [sqlite3_vfs_find()] interface
1323 ** searches the list. Neither the application code nor the VFS
1324 ** implementation should use the pNext pointer.
1326 ** The pNext field is the only field in the sqlite3_vfs
1327 ** structure that SQLite will ever modify. SQLite will only access
1328 ** or modify this field while holding a particular static mutex.
1329 ** The application should never modify anything within the sqlite3_vfs
1330 ** object once the object has been registered.
1332 ** The zName field holds the name of the VFS module. The name must
1333 ** be unique across all VFS modules.
1335 ** [[sqlite3_vfs.xOpen]]
1336 ** ^SQLite guarantees that the zFilename parameter to xOpen
1337 ** is either a NULL pointer or string obtained
1338 ** from xFullPathname() with an optional suffix added.
1339 ** ^If a suffix is added to the zFilename parameter, it will
1340 ** consist of a single "-" character followed by no more than
1341 ** 11 alphanumeric and/or "-" characters.
1342 ** ^SQLite further guarantees that
1343 ** the string will be valid and unchanged until xClose() is
1344 ** called. Because of the previous sentence,
1345 ** the [sqlite3_file] can safely store a pointer to the
1346 ** filename if it needs to remember the filename for some reason.
1347 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1348 ** must invent its own temporary name for the file. ^Whenever the
1349 ** xFilename parameter is NULL it will also be the case that the
1350 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1352 ** The flags argument to xOpen() includes all bits set in
1353 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
1354 ** or [sqlite3_open16()] is used, then flags includes at least
1355 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
1356 ** If xOpen() opens a file read-only then it sets *pOutFlags to
1357 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
1359 ** ^(SQLite will also add one of the following flags to the xOpen()
1360 ** call, depending on the object being opened:
1363 ** <li> [SQLITE_OPEN_MAIN_DB]
1364 ** <li> [SQLITE_OPEN_MAIN_JOURNAL]
1365 ** <li> [SQLITE_OPEN_TEMP_DB]
1366 ** <li> [SQLITE_OPEN_TEMP_JOURNAL]
1367 ** <li> [SQLITE_OPEN_TRANSIENT_DB]
1368 ** <li> [SQLITE_OPEN_SUBJOURNAL]
1369 ** <li> [SQLITE_OPEN_SUPER_JOURNAL]
1370 ** <li> [SQLITE_OPEN_WAL]
1373 ** The file I/O implementation can use the object type flags to
1374 ** change the way it deals with files. For example, an application
1375 ** that does not care about crash recovery or rollback might make
1376 ** the open of a journal file a no-op. Writes to this journal would
1377 ** also be no-ops, and any attempt to read the journal would return
1378 ** SQLITE_IOERR. Or the implementation might recognize that a database
1379 ** file will be doing page-aligned sector reads and writes in a random
1380 ** order and set up its I/O subsystem accordingly.
1382 ** SQLite might also add one of the following flags to the xOpen method:
1385 ** <li> [SQLITE_OPEN_DELETEONCLOSE]
1386 ** <li> [SQLITE_OPEN_EXCLUSIVE]
1389 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1390 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
1391 ** will be set for TEMP databases and their journals, transient
1392 ** databases, and subjournals.
1394 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1395 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1396 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1397 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1398 ** SQLITE_OPEN_CREATE, is used to indicate that file should always
1399 ** be created, and that it is an error if it already exists.
1400 ** It is <i>not</i> used to indicate the file should be opened
1401 ** for exclusive access.
1403 ** ^At least szOsFile bytes of memory are allocated by SQLite
1404 ** to hold the [sqlite3_file] structure passed as the third
1405 ** argument to xOpen. The xOpen method does not have to
1406 ** allocate the structure; it should just fill it in. Note that
1407 ** the xOpen method must set the sqlite3_file.pMethods to either
1408 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
1409 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
1410 ** element will be valid after xOpen returns regardless of the success
1411 ** or failure of the xOpen call.
1413 ** [[sqlite3_vfs.xAccess]]
1414 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1415 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1416 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1417 ** to test whether a file is at least readable. The SQLITE_ACCESS_READ
1418 ** flag is never actually used and is not implemented in the built-in
1419 ** VFSes of SQLite. The file is named by the second argument and can be a
1420 ** directory. The xAccess method returns [SQLITE_OK] on success or some
1421 ** non-zero error code if there is an I/O error or if the name of
1422 ** the file given in the second argument is illegal. If SQLITE_OK
1423 ** is returned, then non-zero or zero is written into *pResOut to indicate
1424 ** whether or not the file is accessible.
1426 ** ^SQLite will always allocate at least mxPathname+1 bytes for the
1427 ** output buffer xFullPathname. The exact size of the output buffer
1428 ** is also passed as a parameter to both methods. If the output buffer
1429 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1430 ** handled as a fatal error by SQLite, vfs implementations should endeavor
1431 ** to prevent this by setting mxPathname to a sufficiently large value.
1433 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1434 ** interfaces are not strictly a part of the filesystem, but they are
1435 ** included in the VFS structure for completeness.
1436 ** The xRandomness() function attempts to return nBytes bytes
1437 ** of good-quality randomness into zOut. The return value is
1438 ** the actual number of bytes of randomness obtained.
1439 ** The xSleep() method causes the calling thread to sleep for at
1440 ** least the number of microseconds given. ^The xCurrentTime()
1441 ** method returns a Julian Day Number for the current date and time as
1442 ** a floating point value.
1443 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1444 ** Day Number multiplied by 86400000 (the number of milliseconds in
1446 ** ^SQLite will use the xCurrentTimeInt64() method to get the current
1447 ** date and time if that method is available (if iVersion is 2 or
1448 ** greater and the function pointer is not NULL) and will fall back
1449 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1451 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1452 ** are not used by the SQLite core. These optional interfaces are provided
1453 ** by some VFSes to facilitate testing of the VFS code. By overriding
1454 ** system calls with functions under its control, a test program can
1455 ** simulate faults and error conditions that would otherwise be difficult
1456 ** or impossible to induce. The set of system calls that can be overridden
1457 ** varies from one VFS to another, and from one version of the same VFS to the
1458 ** next. Applications that use these interfaces must be prepared for any
1459 ** or all of these interfaces to be NULL or for their behavior to change
1460 ** from one release to the next. Applications must not attempt to access
1461 ** any of these methods if the iVersion of the VFS is less than 3.
1463 typedef struct sqlite3_vfs sqlite3_vfs;
1464 typedef void (*sqlite3_syscall_ptr)(void);
1465 struct sqlite3_vfs {
1466 int iVersion; /* Structure version number (currently 3) */
1467 int szOsFile; /* Size of subclassed sqlite3_file */
1468 int mxPathname; /* Maximum file pathname length */
1469 sqlite3_vfs *pNext; /* Next registered VFS */
1470 const char *zName; /* Name of this virtual file system */
1471 void *pAppData; /* Pointer to application-specific data */
1472 int (*xOpen)(sqlite3_vfs*, sqlite3_filename zName, sqlite3_file*,
1473 int flags, int *pOutFlags);
1474 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1475 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1476 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1477 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1478 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1479 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1480 void (*xDlClose)(sqlite3_vfs*, void*);
1481 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1482 int (*xSleep)(sqlite3_vfs*, int microseconds);
1483 int (*xCurrentTime)(sqlite3_vfs*, double*);
1484 int (*xGetLastError)(sqlite3_vfs*, int, char *);
1486 ** The methods above are in version 1 of the sqlite_vfs object
1487 ** definition. Those that follow are added in version 2 or later
1489 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1491 ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1492 ** Those below are for version 3 and greater.
1494 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1495 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1496 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1498 ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1499 ** New fields may be appended in future versions. The iVersion
1500 ** value will increment whenever this happens.
1505 ** CAPI3REF: Flags for the xAccess VFS method
1507 ** These integer constants can be used as the third parameter to
1508 ** the xAccess method of an [sqlite3_vfs] object. They determine
1509 ** what kind of permissions the xAccess method is looking for.
1510 ** With SQLITE_ACCESS_EXISTS, the xAccess method
1511 ** simply checks whether the file exists.
1512 ** With SQLITE_ACCESS_READWRITE, the xAccess method
1513 ** checks whether the named directory is both readable and writable
1514 ** (in other words, if files can be added, removed, and renamed within
1516 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1517 ** [temp_store_directory pragma], though this could change in a future
1518 ** release of SQLite.
1519 ** With SQLITE_ACCESS_READ, the xAccess method
1520 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
1521 ** currently unused, though it might be used in a future release of
1524 #define SQLITE_ACCESS_EXISTS 0
1525 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
1526 #define SQLITE_ACCESS_READ 2 /* Unused */
1529 ** CAPI3REF: Flags for the xShmLock VFS method
1531 ** These integer constants define the various locking operations
1532 ** allowed by the xShmLock method of [sqlite3_io_methods]. The
1533 ** following are the only legal combinations of flags to the
1537 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1538 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1539 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1540 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1543 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1544 ** was given on the corresponding lock.
1546 ** The xShmLock method can transition between unlocked and SHARED or
1547 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED
1550 #define SQLITE_SHM_UNLOCK 1
1551 #define SQLITE_SHM_LOCK 2
1552 #define SQLITE_SHM_SHARED 4
1553 #define SQLITE_SHM_EXCLUSIVE 8
1556 ** CAPI3REF: Maximum xShmLock index
1558 ** The xShmLock method on [sqlite3_io_methods] may use values
1559 ** between 0 and this upper bound as its "offset" argument.
1560 ** The SQLite core will never attempt to acquire or release a
1561 ** lock outside of this range
1563 #define SQLITE_SHM_NLOCK 8
1567 ** CAPI3REF: Initialize The SQLite Library
1569 ** ^The sqlite3_initialize() routine initializes the
1570 ** SQLite library. ^The sqlite3_shutdown() routine
1571 ** deallocates any resources that were allocated by sqlite3_initialize().
1572 ** These routines are designed to aid in process initialization and
1573 ** shutdown on embedded systems. Workstation applications using
1574 ** SQLite normally do not need to invoke either of these routines.
1576 ** A call to sqlite3_initialize() is an "effective" call if it is
1577 ** the first time sqlite3_initialize() is invoked during the lifetime of
1578 ** the process, or if it is the first time sqlite3_initialize() is invoked
1579 ** following a call to sqlite3_shutdown(). ^(Only an effective call
1580 ** of sqlite3_initialize() does any initialization. All other calls
1581 ** are harmless no-ops.)^
1583 ** A call to sqlite3_shutdown() is an "effective" call if it is the first
1584 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
1585 ** an effective call to sqlite3_shutdown() does any deinitialization.
1586 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1588 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1589 ** is not. The sqlite3_shutdown() interface must only be called from a
1590 ** single thread. All open [database connections] must be closed and all
1591 ** other SQLite resources must be deallocated prior to invoking
1592 ** sqlite3_shutdown().
1594 ** Among other things, ^sqlite3_initialize() will invoke
1595 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
1596 ** will invoke sqlite3_os_end().
1598 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1599 ** ^If for some reason, sqlite3_initialize() is unable to initialize
1600 ** the library (perhaps it is unable to allocate a needed resource such
1601 ** as a mutex) it returns an [error code] other than [SQLITE_OK].
1603 ** ^The sqlite3_initialize() routine is called internally by many other
1604 ** SQLite interfaces so that an application usually does not need to
1605 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
1606 ** calls sqlite3_initialize() so the SQLite library will be automatically
1607 ** initialized when [sqlite3_open()] is called if it has not be initialized
1608 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1609 ** compile-time option, then the automatic calls to sqlite3_initialize()
1610 ** are omitted and the application must call sqlite3_initialize() directly
1611 ** prior to using any other SQLite interface. For maximum portability,
1612 ** it is recommended that applications always invoke sqlite3_initialize()
1613 ** directly prior to using any other SQLite interface. Future releases
1614 ** of SQLite may require this. In other words, the behavior exhibited
1615 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1616 ** default behavior in some future release of SQLite.
1618 ** The sqlite3_os_init() routine does operating-system specific
1619 ** initialization of the SQLite library. The sqlite3_os_end()
1620 ** routine undoes the effect of sqlite3_os_init(). Typical tasks
1621 ** performed by these routines include allocation or deallocation
1622 ** of static resources, initialization of global variables,
1623 ** setting up a default [sqlite3_vfs] module, or setting up
1624 ** a default configuration using [sqlite3_config()].
1626 ** The application should never invoke either sqlite3_os_init()
1627 ** or sqlite3_os_end() directly. The application should only invoke
1628 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
1629 ** interface is called automatically by sqlite3_initialize() and
1630 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
1631 ** implementations for sqlite3_os_init() and sqlite3_os_end()
1632 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1633 ** When [custom builds | built for other platforms]
1634 ** (using the [SQLITE_OS_OTHER=1] compile-time
1635 ** option) the application must supply a suitable implementation for
1636 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
1637 ** implementation of sqlite3_os_init() or sqlite3_os_end()
1638 ** must return [SQLITE_OK] on success and some other [error code] upon
1641 SQLITE_API int sqlite3_initialize(void);
1642 SQLITE_API int sqlite3_shutdown(void);
1643 SQLITE_API int sqlite3_os_init(void);
1644 SQLITE_API int sqlite3_os_end(void);
1647 ** CAPI3REF: Configuring The SQLite Library
1649 ** The sqlite3_config() interface is used to make global configuration
1650 ** changes to SQLite in order to tune SQLite to the specific needs of
1651 ** the application. The default configuration is recommended for most
1652 ** applications and so this routine is usually not necessary. It is
1653 ** provided to support rare applications with unusual needs.
1655 ** <b>The sqlite3_config() interface is not threadsafe. The application
1656 ** must ensure that no other SQLite interfaces are invoked by other
1657 ** threads while sqlite3_config() is running.</b>
1659 ** The first argument to sqlite3_config() is an integer
1660 ** [configuration option] that determines
1661 ** what property of SQLite is to be configured. Subsequent arguments
1662 ** vary depending on the [configuration option]
1663 ** in the first argument.
1665 ** For most configuration options, the sqlite3_config() interface
1666 ** may only be invoked prior to library initialization using
1667 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1668 ** The exceptional configuration options that may be invoked at any time
1669 ** are called "anytime configuration options".
1670 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1671 ** [sqlite3_shutdown()] with a first argument that is not an anytime
1672 ** configuration option, then the sqlite3_config() call will return SQLITE_MISUSE.
1673 ** Note, however, that ^sqlite3_config() can be called as part of the
1674 ** implementation of an application-defined [sqlite3_os_init()].
1676 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1677 ** ^If the option is unknown or SQLite is unable to set the option
1678 ** then this routine returns a non-zero [error code].
1680 SQLITE_API int sqlite3_config(int, ...);
1683 ** CAPI3REF: Configure database connections
1686 ** The sqlite3_db_config() interface is used to make configuration
1687 ** changes to a [database connection]. The interface is similar to
1688 ** [sqlite3_config()] except that the changes apply to a single
1689 ** [database connection] (specified in the first argument).
1691 ** The second argument to sqlite3_db_config(D,V,...) is the
1692 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1693 ** that indicates what aspect of the [database connection] is being configured.
1694 ** Subsequent arguments vary depending on the configuration verb.
1696 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1697 ** the call is considered successful.
1699 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1702 ** CAPI3REF: Memory Allocation Routines
1704 ** An instance of this object defines the interface between SQLite
1705 ** and low-level memory allocation routines.
1707 ** This object is used in only one place in the SQLite interface.
1708 ** A pointer to an instance of this object is the argument to
1709 ** [sqlite3_config()] when the configuration option is
1710 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1711 ** By creating an instance of this object
1712 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1713 ** during configuration, an application can specify an alternative
1714 ** memory allocation subsystem for SQLite to use for all of its
1715 ** dynamic memory needs.
1717 ** Note that SQLite comes with several [built-in memory allocators]
1718 ** that are perfectly adequate for the overwhelming majority of applications
1719 ** and that this object is only useful to a tiny minority of applications
1720 ** with specialized memory allocation requirements. This object is
1721 ** also used during testing of SQLite in order to specify an alternative
1722 ** memory allocator that simulates memory out-of-memory conditions in
1723 ** order to verify that SQLite recovers gracefully from such
1726 ** The xMalloc, xRealloc, and xFree methods must work like the
1727 ** malloc(), realloc() and free() functions from the standard C library.
1728 ** ^SQLite guarantees that the second argument to
1729 ** xRealloc is always a value returned by a prior call to xRoundup.
1731 ** xSize should return the allocated size of a memory allocation
1732 ** previously obtained from xMalloc or xRealloc. The allocated size
1733 ** is always at least as big as the requested size but may be larger.
1735 ** The xRoundup method returns what would be the allocated size of
1736 ** a memory allocation given a particular requested size. Most memory
1737 ** allocators round up memory allocations at least to the next multiple
1738 ** of 8. Some allocators round up to a larger multiple or to a power of 2.
1739 ** Every memory allocation request coming in through [sqlite3_malloc()]
1740 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1741 ** that causes the corresponding memory allocation to fail.
1743 ** The xInit method initializes the memory allocator. For example,
1744 ** it might allocate any required mutexes or initialize internal data
1745 ** structures. The xShutdown method is invoked (indirectly) by
1746 ** [sqlite3_shutdown()] and should deallocate any resources acquired
1747 ** by xInit. The pAppData pointer is used as the only parameter to
1748 ** xInit and xShutdown.
1750 ** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes
1751 ** the xInit method, so the xInit method need not be threadsafe. The
1752 ** xShutdown method is only called from [sqlite3_shutdown()] so it does
1753 ** not need to be threadsafe either. For all other methods, SQLite
1754 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1755 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1756 ** it is by default) and so the methods are automatically serialized.
1757 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1758 ** methods must be threadsafe or else make their own arrangements for
1761 ** SQLite will never invoke xInit() more than once without an intervening
1762 ** call to xShutdown().
1764 typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1765 struct sqlite3_mem_methods {
1766 void *(*xMalloc)(int); /* Memory allocation function */
1767 void (*xFree)(void*); /* Free a prior allocation */
1768 void *(*xRealloc)(void*,int); /* Resize an allocation */
1769 int (*xSize)(void*); /* Return the size of an allocation */
1770 int (*xRoundup)(int); /* Round up request size to allocation size */
1771 int (*xInit)(void*); /* Initialize the memory allocator */
1772 void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1773 void *pAppData; /* Argument to xInit() and xShutdown() */
1777 ** CAPI3REF: Configuration Options
1778 ** KEYWORDS: {configuration option}
1780 ** These constants are the available integer configuration options that
1781 ** can be passed as the first argument to the [sqlite3_config()] interface.
1783 ** Most of the configuration options for sqlite3_config()
1784 ** will only work if invoked prior to [sqlite3_initialize()] or after
1785 ** [sqlite3_shutdown()]. The few exceptions to this rule are called
1786 ** "anytime configuration options".
1787 ** ^Calling [sqlite3_config()] with a first argument that is not an
1788 ** anytime configuration option in between calls to [sqlite3_initialize()] and
1789 ** [sqlite3_shutdown()] is a no-op that returns SQLITE_MISUSE.
1791 ** The set of anytime configuration options can change (by insertions
1792 ** and/or deletions) from one release of SQLite to the next.
1793 ** As of SQLite version 3.42.0, the complete set of anytime configuration
1796 ** <li> SQLITE_CONFIG_LOG
1797 ** <li> SQLITE_CONFIG_PCACHE_HDRSZ
1800 ** New configuration options may be added in future releases of SQLite.
1801 ** Existing configuration options might be discontinued. Applications
1802 ** should check the return code from [sqlite3_config()] to make sure that
1803 ** the call worked. The [sqlite3_config()] interface will return a
1804 ** non-zero [error code] if a discontinued or unsupported configuration option
1808 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1809 ** <dd>There are no arguments to this option. ^This option sets the
1810 ** [threading mode] to Single-thread. In other words, it disables
1811 ** all mutexing and puts SQLite into a mode where it can only be used
1812 ** by a single thread. ^If SQLite is compiled with
1813 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1814 ** it is not possible to change the [threading mode] from its default
1815 ** value of Single-thread and so [sqlite3_config()] will return
1816 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1817 ** configuration option.</dd>
1819 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1820 ** <dd>There are no arguments to this option. ^This option sets the
1821 ** [threading mode] to Multi-thread. In other words, it disables
1822 ** mutexing on [database connection] and [prepared statement] objects.
1823 ** The application is responsible for serializing access to
1824 ** [database connections] and [prepared statements]. But other mutexes
1825 ** are enabled so that SQLite will be safe to use in a multi-threaded
1826 ** environment as long as no two threads attempt to use the same
1827 ** [database connection] at the same time. ^If SQLite is compiled with
1828 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1829 ** it is not possible to set the Multi-thread [threading mode] and
1830 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1831 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1833 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1834 ** <dd>There are no arguments to this option. ^This option sets the
1835 ** [threading mode] to Serialized. In other words, this option enables
1836 ** all mutexes including the recursive
1837 ** mutexes on [database connection] and [prepared statement] objects.
1838 ** In this mode (which is the default when SQLite is compiled with
1839 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1840 ** to [database connections] and [prepared statements] so that the
1841 ** application is free to use the same [database connection] or the
1842 ** same [prepared statement] in different threads at the same time.
1843 ** ^If SQLite is compiled with
1844 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1845 ** it is not possible to set the Serialized [threading mode] and
1846 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1847 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1849 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1850 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is
1851 ** a pointer to an instance of the [sqlite3_mem_methods] structure.
1852 ** The argument specifies
1853 ** alternative low-level memory allocation routines to be used in place of
1854 ** the memory allocation routines built into SQLite.)^ ^SQLite makes
1855 ** its own private copy of the content of the [sqlite3_mem_methods] structure
1856 ** before the [sqlite3_config()] call returns.</dd>
1858 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1859 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
1860 ** is a pointer to an instance of the [sqlite3_mem_methods] structure.
1861 ** The [sqlite3_mem_methods]
1862 ** structure is filled with the currently defined memory allocation routines.)^
1863 ** This option can be used to overload the default memory allocation
1864 ** routines with a wrapper that simulations memory allocation failure or
1865 ** tracks memory usage, for example. </dd>
1867 ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt>
1868 ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of
1869 ** type int, interpreted as a boolean, which if true provides a hint to
1870 ** SQLite that it should avoid large memory allocations if possible.
1871 ** SQLite will run faster if it is free to make large memory allocations,
1872 ** but some application might prefer to run slower in exchange for
1873 ** guarantees about memory fragmentation that are possible if large
1874 ** allocations are avoided. This hint is normally off.
1877 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1878 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
1879 ** interpreted as a boolean, which enables or disables the collection of
1880 ** memory allocation statistics. ^(When memory allocation statistics are
1881 ** disabled, the following SQLite interfaces become non-operational:
1883 ** <li> [sqlite3_hard_heap_limit64()]
1884 ** <li> [sqlite3_memory_used()]
1885 ** <li> [sqlite3_memory_highwater()]
1886 ** <li> [sqlite3_soft_heap_limit64()]
1887 ** <li> [sqlite3_status64()]
1889 ** ^Memory allocation statistics are enabled by default unless SQLite is
1890 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1891 ** allocation statistics are disabled by default.
1894 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1895 ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used.
1898 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1899 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
1900 ** that SQLite can use for the database page cache with the default page
1901 ** cache implementation.
1902 ** This configuration option is a no-op if an application-defined page
1903 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
1904 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
1905 ** 8-byte aligned memory (pMem), the size of each page cache line (sz),
1906 ** and the number of cache lines (N).
1907 ** The sz argument should be the size of the largest database page
1908 ** (a power of two between 512 and 65536) plus some extra bytes for each
1909 ** page header. ^The number of extra bytes needed by the page header
1910 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
1911 ** ^It is harmless, apart from the wasted memory,
1912 ** for the sz parameter to be larger than necessary. The pMem
1913 ** argument must be either a NULL pointer or a pointer to an 8-byte
1914 ** aligned block of memory of at least sz*N bytes, otherwise
1915 ** subsequent behavior is undefined.
1916 ** ^When pMem is not NULL, SQLite will strive to use the memory provided
1917 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
1918 ** a page cache line is larger than sz bytes or if all of the pMem buffer
1920 ** ^If pMem is NULL and N is non-zero, then each database connection
1921 ** does an initial bulk allocation for page cache memory
1922 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
1923 ** of -1024*N bytes if N is negative, . ^If additional
1924 ** page cache memory is needed beyond what is provided by the initial
1925 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
1926 ** additional cache line. </dd>
1928 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1929 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer
1930 ** that SQLite will use for all of its dynamic memory allocation needs
1931 ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE].
1932 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
1933 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
1934 ** [SQLITE_ERROR] if invoked otherwise.
1935 ** ^There are three arguments to SQLITE_CONFIG_HEAP:
1936 ** An 8-byte aligned pointer to the memory,
1937 ** the number of bytes in the memory buffer, and the minimum allocation size.
1938 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1939 ** to using its default memory allocator (the system malloc() implementation),
1940 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
1941 ** memory pointer is not NULL then the alternative memory
1942 ** allocator is engaged to handle all of SQLites memory allocation needs.
1943 ** The first pointer (the memory pointer) must be aligned to an 8-byte
1944 ** boundary or subsequent behavior of SQLite will be undefined.
1945 ** The minimum allocation size is capped at 2**12. Reasonable values
1946 ** for the minimum allocation size are 2**5 through 2**8.</dd>
1948 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1949 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
1950 ** pointer to an instance of the [sqlite3_mutex_methods] structure.
1951 ** The argument specifies alternative low-level mutex routines to be used
1952 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of
1953 ** the content of the [sqlite3_mutex_methods] structure before the call to
1954 ** [sqlite3_config()] returns. ^If SQLite is compiled with
1955 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1956 ** the entire mutexing subsystem is omitted from the build and hence calls to
1957 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1958 ** return [SQLITE_ERROR].</dd>
1960 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
1961 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
1962 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The
1963 ** [sqlite3_mutex_methods]
1964 ** structure is filled with the currently defined mutex routines.)^
1965 ** This option can be used to overload the default mutex allocation
1966 ** routines with a wrapper used to track mutex usage for performance
1967 ** profiling or testing, for example. ^If SQLite is compiled with
1968 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1969 ** the entire mutexing subsystem is omitted from the build and hence calls to
1970 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1971 ** return [SQLITE_ERROR].</dd>
1973 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1974 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
1975 ** the default size of lookaside memory on each [database connection].
1976 ** The first argument is the
1977 ** size of each lookaside buffer slot and the second is the number of
1978 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE
1979 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
1980 ** option to [sqlite3_db_config()] can be used to change the lookaside
1981 ** configuration on individual connections.)^ </dd>
1983 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
1984 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is
1985 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies
1986 ** the interface to a custom page cache implementation.)^
1987 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
1989 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
1990 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
1991 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of
1992 ** the current page cache implementation into that object.)^ </dd>
1994 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
1995 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
1996 ** global [error log].
1997 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
1998 ** function with a call signature of void(*)(void*,int,const char*),
1999 ** and a pointer to void. ^If the function pointer is not NULL, it is
2000 ** invoked by [sqlite3_log()] to process each logging event. ^If the
2001 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
2002 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
2003 ** passed through as the first parameter to the application-defined logger
2004 ** function whenever that function is invoked. ^The second parameter to
2005 ** the logger function is a copy of the first parameter to the corresponding
2006 ** [sqlite3_log()] call and is intended to be a [result code] or an
2007 ** [extended result code]. ^The third parameter passed to the logger is
2008 ** log message after formatting via [sqlite3_snprintf()].
2009 ** The SQLite logging interface is not reentrant; the logger function
2010 ** supplied by the application must not invoke any SQLite interface.
2011 ** In a multi-threaded application, the application-defined logger
2012 ** function must be threadsafe. </dd>
2014 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
2015 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
2016 ** If non-zero, then URI handling is globally enabled. If the parameter is zero,
2017 ** then URI handling is globally disabled.)^ ^If URI handling is globally
2018 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
2019 ** [sqlite3_open16()] or
2020 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless
2021 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
2022 ** connection is opened. ^If it is globally disabled, filenames are
2023 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
2024 ** database connection is opened. ^(By default, URI handling is globally
2025 ** disabled. The default value may be changed by compiling with the
2026 ** [SQLITE_USE_URI] symbol defined.)^
2028 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
2029 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
2030 ** argument which is interpreted as a boolean in order to enable or disable
2031 ** the use of covering indices for full table scans in the query optimizer.
2032 ** ^The default setting is determined
2033 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
2034 ** if that compile-time option is omitted.
2035 ** The ability to disable the use of covering indices for full table scans
2036 ** is because some incorrectly coded legacy applications might malfunction
2037 ** when the optimization is enabled. Providing the ability to
2038 ** disable the optimization allows the older, buggy application code to work
2039 ** without change even with newer versions of SQLite.
2041 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
2042 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
2043 ** <dd> These options are obsolete and should not be used by new code.
2044 ** They are retained for backwards compatibility but are now no-ops.
2047 ** [[SQLITE_CONFIG_SQLLOG]]
2048 ** <dt>SQLITE_CONFIG_SQLLOG
2049 ** <dd>This option is only available if sqlite is compiled with the
2050 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
2051 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
2052 ** The second should be of type (void*). The callback is invoked by the library
2053 ** in three separate circumstances, identified by the value passed as the
2054 ** fourth parameter. If the fourth parameter is 0, then the database connection
2055 ** passed as the second argument has just been opened. The third argument
2056 ** points to a buffer containing the name of the main database file. If the
2057 ** fourth parameter is 1, then the SQL statement that the third parameter
2058 ** points to has just been executed. Or, if the fourth parameter is 2, then
2059 ** the connection being passed as the second parameter is being closed. The
2060 ** third parameter is passed NULL In this case. An example of using this
2061 ** configuration option can be seen in the "test_sqllog.c" source file in
2062 ** the canonical SQLite source tree.</dd>
2064 ** [[SQLITE_CONFIG_MMAP_SIZE]]
2065 ** <dt>SQLITE_CONFIG_MMAP_SIZE
2066 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
2067 ** that are the default mmap size limit (the default setting for
2068 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
2069 ** ^The default setting can be overridden by each database connection using
2070 ** either the [PRAGMA mmap_size] command, or by using the
2071 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size
2072 ** will be silently truncated if necessary so that it does not exceed the
2073 ** compile-time maximum mmap size set by the
2074 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
2075 ** ^If either argument to this option is negative, then that argument is
2076 ** changed to its compile-time default.
2078 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
2079 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
2080 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
2081 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
2082 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
2083 ** that specifies the maximum size of the created heap.
2085 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
2086 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
2087 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
2088 ** is a pointer to an integer and writes into that integer the number of extra
2089 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
2090 ** The amount of extra space required can change depending on the compiler,
2091 ** target platform, and SQLite version.
2093 ** [[SQLITE_CONFIG_PMASZ]]
2094 ** <dt>SQLITE_CONFIG_PMASZ
2095 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
2096 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
2097 ** sorter to that integer. The default minimum PMA Size is set by the
2098 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched
2099 ** to help with sort operations when multithreaded sorting
2100 ** is enabled (using the [PRAGMA threads] command) and the amount of content
2101 ** to be sorted exceeds the page size times the minimum of the
2102 ** [PRAGMA cache_size] setting and this value.
2104 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
2105 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL
2106 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
2107 ** becomes the [statement journal] spill-to-disk threshold.
2108 ** [Statement journals] are held in memory until their size (in bytes)
2109 ** exceeds this threshold, at which point they are written to disk.
2110 ** Or if the threshold is -1, statement journals are always held
2111 ** exclusively in memory.
2112 ** Since many statement journals never become large, setting the spill
2113 ** threshold to a value such as 64KiB can greatly reduce the amount of
2114 ** I/O required to support statement rollback.
2115 ** The default value for this setting is controlled by the
2116 ** [SQLITE_STMTJRNL_SPILL] compile-time option.
2118 ** [[SQLITE_CONFIG_SORTERREF_SIZE]]
2119 ** <dt>SQLITE_CONFIG_SORTERREF_SIZE
2120 ** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter
2121 ** of type (int) - the new value of the sorter-reference size threshold.
2122 ** Usually, when SQLite uses an external sort to order records according
2123 ** to an ORDER BY clause, all fields required by the caller are present in the
2124 ** sorted records. However, if SQLite determines based on the declared type
2125 ** of a table column that its values are likely to be very large - larger
2126 ** than the configured sorter-reference size threshold - then a reference
2127 ** is stored in each sorted record and the required column values loaded
2128 ** from the database as records are returned in sorted order. The default
2129 ** value for this option is to never use this optimization. Specifying a
2130 ** negative value for this option restores the default behavior.
2131 ** This option is only available if SQLite is compiled with the
2132 ** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option.
2134 ** [[SQLITE_CONFIG_MEMDB_MAXSIZE]]
2135 ** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE
2136 ** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter
2137 ** [sqlite3_int64] parameter which is the default maximum size for an in-memory
2138 ** database created using [sqlite3_deserialize()]. This default maximum
2139 ** size can be adjusted up or down for individual databases using the
2140 ** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this
2141 ** configuration setting is never used, then the default maximum is determined
2142 ** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that
2143 ** compile-time option is not set, then the default maximum is 1073741824.
2146 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
2147 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
2148 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */
2149 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
2150 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
2151 #define SQLITE_CONFIG_SCRATCH 6 /* No longer used */
2152 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
2153 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
2154 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
2155 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
2156 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
2157 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
2158 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
2159 #define SQLITE_CONFIG_PCACHE 14 /* no-op */
2160 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */
2161 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
2162 #define SQLITE_CONFIG_URI 17 /* int */
2163 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */
2164 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */
2165 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */
2166 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */
2167 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */
2168 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */
2169 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */
2170 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */
2171 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */
2172 #define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */
2173 #define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */
2174 #define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */
2177 ** CAPI3REF: Database Connection Configuration Options
2179 ** These constants are the available integer configuration options that
2180 ** can be passed as the second argument to the [sqlite3_db_config()] interface.
2182 ** New configuration options may be added in future releases of SQLite.
2183 ** Existing configuration options might be discontinued. Applications
2184 ** should check the return code from [sqlite3_db_config()] to make sure that
2185 ** the call worked. ^The [sqlite3_db_config()] interface will return a
2186 ** non-zero [error code] if a discontinued or unsupported configuration option
2190 ** [[SQLITE_DBCONFIG_LOOKASIDE]]
2191 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
2192 ** <dd> ^This option takes three additional arguments that determine the
2193 ** [lookaside memory allocator] configuration for the [database connection].
2194 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a
2195 ** pointer to a memory buffer to use for lookaside memory.
2196 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
2197 ** may be NULL in which case SQLite will allocate the
2198 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
2199 ** size of each lookaside buffer slot. ^The third argument is the number of
2200 ** slots. The size of the buffer in the first argument must be greater than
2201 ** or equal to the product of the second and third arguments. The buffer
2202 ** must be aligned to an 8-byte boundary. ^If the second argument to
2203 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
2204 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory
2205 ** configuration for a database connection can only be changed when that
2206 ** connection is not currently using lookaside memory, or in other words
2207 ** when the "current value" returned by
2208 ** [sqlite3_db_status](D,[SQLITE_DBSTATUS_LOOKASIDE_USED],...) is zero.
2209 ** Any attempt to change the lookaside memory configuration when lookaside
2210 ** memory is in use leaves the configuration unchanged and returns
2211 ** [SQLITE_BUSY].)^</dd>
2213 ** [[SQLITE_DBCONFIG_ENABLE_FKEY]]
2214 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
2215 ** <dd> ^This option is used to enable or disable the enforcement of
2216 ** [foreign key constraints]. There should be two additional arguments.
2217 ** The first argument is an integer which is 0 to disable FK enforcement,
2218 ** positive to enable FK enforcement or negative to leave FK enforcement
2219 ** unchanged. The second parameter is a pointer to an integer into which
2220 ** is written 0 or 1 to indicate whether FK enforcement is off or on
2221 ** following this call. The second parameter may be a NULL pointer, in
2222 ** which case the FK enforcement setting is not reported back. </dd>
2224 ** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]]
2225 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
2226 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
2227 ** There should be two additional arguments.
2228 ** The first argument is an integer which is 0 to disable triggers,
2229 ** positive to enable triggers or negative to leave the setting unchanged.
2230 ** The second parameter is a pointer to an integer into which
2231 ** is written 0 or 1 to indicate whether triggers are disabled or enabled
2232 ** following this call. The second parameter may be a NULL pointer, in
2233 ** which case the trigger setting is not reported back.
2235 ** <p>Originally this option disabled all triggers. ^(However, since
2236 ** SQLite version 3.35.0, TEMP triggers are still allowed even if
2237 ** this option is off. So, in other words, this option now only disables
2238 ** triggers in the main database schema or in the schemas of ATTACH-ed
2239 ** databases.)^ </dd>
2241 ** [[SQLITE_DBCONFIG_ENABLE_VIEW]]
2242 ** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt>
2243 ** <dd> ^This option is used to enable or disable [CREATE VIEW | views].
2244 ** There should be two additional arguments.
2245 ** The first argument is an integer which is 0 to disable views,
2246 ** positive to enable views or negative to leave the setting unchanged.
2247 ** The second parameter is a pointer to an integer into which
2248 ** is written 0 or 1 to indicate whether views are disabled or enabled
2249 ** following this call. The second parameter may be a NULL pointer, in
2250 ** which case the view setting is not reported back.
2252 ** <p>Originally this option disabled all views. ^(However, since
2253 ** SQLite version 3.35.0, TEMP views are still allowed even if
2254 ** this option is off. So, in other words, this option now only disables
2255 ** views in the main database schema or in the schemas of ATTACH-ed
2256 ** databases.)^ </dd>
2258 ** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]]
2259 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
2260 ** <dd> ^This option is used to enable or disable the
2261 ** [fts3_tokenizer()] function which is part of the
2262 ** [FTS3] full-text search engine extension.
2263 ** There should be two additional arguments.
2264 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or
2265 ** positive to enable fts3_tokenizer() or negative to leave the setting
2267 ** The second parameter is a pointer to an integer into which
2268 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled
2269 ** following this call. The second parameter may be a NULL pointer, in
2270 ** which case the new setting is not reported back. </dd>
2272 ** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]]
2273 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>
2274 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]
2275 ** interface independently of the [load_extension()] SQL function.
2276 ** The [sqlite3_enable_load_extension()] API enables or disables both the
2277 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
2278 ** There should be two additional arguments.
2279 ** When the first argument to this interface is 1, then only the C-API is
2280 ** enabled and the SQL function remains disabled. If the first argument to
2281 ** this interface is 0, then both the C-API and the SQL function are disabled.
2282 ** If the first argument is -1, then no changes are made to state of either the
2283 ** C-API or the SQL function.
2284 ** The second parameter is a pointer to an integer into which
2285 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
2286 ** is disabled or enabled following this call. The second parameter may
2287 ** be a NULL pointer, in which case the new setting is not reported back.
2290 ** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt>
2291 ** <dd> ^This option is used to change the name of the "main" database
2292 ** schema. ^The sole argument is a pointer to a constant UTF8 string
2293 ** which will become the new schema name in place of "main". ^SQLite
2294 ** does not make a copy of the new main schema name string, so the application
2295 ** must ensure that the argument passed into this DBCONFIG option is unchanged
2296 ** until after the database connection closes.
2299 ** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]]
2300 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt>
2301 ** <dd> Usually, when a database in wal mode is closed or detached from a
2302 ** database handle, SQLite checks if this will mean that there are now no
2303 ** connections at all to the database. If so, it performs a checkpoint
2304 ** operation before closing the connection. This option may be used to
2305 ** override this behavior. The first parameter passed to this operation
2306 ** is an integer - positive to disable checkpoints-on-close, or zero (the
2307 ** default) to enable them, and negative to leave the setting unchanged.
2308 ** The second parameter is a pointer to an integer
2309 ** into which is written 0 or 1 to indicate whether checkpoints-on-close
2310 ** have been disabled - 0 if they are not disabled, 1 if they are.
2313 ** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt>
2314 ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates
2315 ** the [query planner stability guarantee] (QPSG). When the QPSG is active,
2316 ** a single SQL query statement will always use the same algorithm regardless
2317 ** of values of [bound parameters].)^ The QPSG disables some query optimizations
2318 ** that look at the values of bound parameters, which can make some queries
2319 ** slower. But the QPSG has the advantage of more predictable behavior. With
2320 ** the QPSG active, SQLite will always use the same query plan in the field as
2321 ** was used during testing in the lab.
2322 ** The first argument to this setting is an integer which is 0 to disable
2323 ** the QPSG, positive to enable QPSG, or negative to leave the setting
2324 ** unchanged. The second parameter is a pointer to an integer into which
2325 ** is written 0 or 1 to indicate whether the QPSG is disabled or enabled
2326 ** following this call.
2329 ** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt>
2330 ** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not
2331 ** include output for any operations performed by trigger programs. This
2332 ** option is used to set or clear (the default) a flag that governs this
2333 ** behavior. The first parameter passed to this operation is an integer -
2334 ** positive to enable output for trigger programs, or zero to disable it,
2335 ** or negative to leave the setting unchanged.
2336 ** The second parameter is a pointer to an integer into which is written
2337 ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if
2338 ** it is not disabled, 1 if it is.
2341 ** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt>
2342 ** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run
2343 ** [VACUUM] in order to reset a database back to an empty database
2344 ** with no schema and no content. The following process works even for
2345 ** a badly corrupted database file:
2347 ** <li> If the database connection is newly opened, make sure it has read the
2348 ** database schema by preparing then discarding some query against the
2349 ** database, or calling sqlite3_table_column_metadata(), ignoring any
2350 ** errors. This step is only necessary if the application desires to keep
2351 ** the database in WAL mode after the reset if it was in WAL mode before
2353 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0);
2354 ** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0);
2355 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0);
2357 ** Because resetting a database is destructive and irreversible, the
2358 ** process requires the use of this obscure API and multiple steps to
2359 ** help ensure that it does not happen by accident. Because this
2360 ** feature must be capable of resetting corrupt databases, and
2361 ** shutting down virtual tables may require access to that corrupt
2362 ** storage, the library must abandon any installed virtual tables
2363 ** without calling their xDestroy() methods.
2365 ** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt>
2366 ** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the
2367 ** "defensive" flag for a database connection. When the defensive
2368 ** flag is enabled, language features that allow ordinary SQL to
2369 ** deliberately corrupt the database file are disabled. The disabled
2370 ** features include but are not limited to the following:
2372 ** <li> The [PRAGMA writable_schema=ON] statement.
2373 ** <li> The [PRAGMA journal_mode=OFF] statement.
2374 ** <li> The [PRAGMA schema_version=N] statement.
2375 ** <li> Writes to the [sqlite_dbpage] virtual table.
2376 ** <li> Direct writes to [shadow tables].
2380 ** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt>
2381 ** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the
2382 ** "writable_schema" flag. This has the same effect and is logically equivalent
2383 ** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF].
2384 ** The first argument to this setting is an integer which is 0 to disable
2385 ** the writable_schema, positive to enable writable_schema, or negative to
2386 ** leave the setting unchanged. The second parameter is a pointer to an
2387 ** integer into which is written 0 or 1 to indicate whether the writable_schema
2388 ** is enabled or disabled following this call.
2391 ** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]]
2392 ** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt>
2393 ** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates
2394 ** the legacy behavior of the [ALTER TABLE RENAME] command such it
2395 ** behaves as it did prior to [version 3.24.0] (2018-06-04). See the
2396 ** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for
2397 ** additional information. This feature can also be turned on and off
2398 ** using the [PRAGMA legacy_alter_table] statement.
2401 ** [[SQLITE_DBCONFIG_DQS_DML]]
2402 ** <dt>SQLITE_DBCONFIG_DQS_DML</dt>
2403 ** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates
2404 ** the legacy [double-quoted string literal] misfeature for DML statements
2405 ** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The
2406 ** default value of this setting is determined by the [-DSQLITE_DQS]
2407 ** compile-time option.
2410 ** [[SQLITE_DBCONFIG_DQS_DDL]]
2411 ** <dt>SQLITE_DBCONFIG_DQS_DDL</dt>
2412 ** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates
2413 ** the legacy [double-quoted string literal] misfeature for DDL statements,
2414 ** such as CREATE TABLE and CREATE INDEX. The
2415 ** default value of this setting is determined by the [-DSQLITE_DQS]
2416 ** compile-time option.
2419 ** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]]
2420 ** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</dt>
2421 ** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to
2422 ** assume that database schemas are untainted by malicious content.
2423 ** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite
2424 ** takes additional defensive steps to protect the application from harm
2427 ** <li> Prohibit the use of SQL functions inside triggers, views,
2428 ** CHECK constraints, DEFAULT clauses, expression indexes,
2429 ** partial indexes, or generated columns
2430 ** unless those functions are tagged with [SQLITE_INNOCUOUS].
2431 ** <li> Prohibit the use of virtual tables inside of triggers or views
2432 ** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS].
2434 ** This setting defaults to "on" for legacy compatibility, however
2435 ** all applications are advised to turn it off if possible. This setting
2436 ** can also be controlled using the [PRAGMA trusted_schema] statement.
2439 ** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]]
2440 ** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</dt>
2441 ** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates
2442 ** the legacy file format flag. When activated, this flag causes all newly
2443 ** created database file to have a schema format version number (the 4-byte
2444 ** integer found at offset 44 into the database header) of 1. This in turn
2445 ** means that the resulting database file will be readable and writable by
2446 ** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting,
2447 ** newly created databases are generally not understandable by SQLite versions
2448 ** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there
2449 ** is now scarcely any need to generate database files that are compatible
2450 ** all the way back to version 3.0.0, and so this setting is of little
2451 ** practical use, but is provided so that SQLite can continue to claim the
2452 ** ability to generate new database files that are compatible with version
2454 ** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on,
2455 ** the [VACUUM] command will fail with an obscure error when attempting to
2456 ** process a table with generated columns and a descending index. This is
2457 ** not considered a bug since SQLite versions 3.3.0 and earlier do not support
2458 ** either generated columns or descending indexes.
2461 ** [[SQLITE_DBCONFIG_STMT_SCANSTATUS]]
2462 ** <dt>SQLITE_DBCONFIG_STMT_SCANSTATUS</dt>
2463 ** <dd>The SQLITE_DBCONFIG_STMT_SCANSTATUS option is only useful in
2464 ** SQLITE_ENABLE_STMT_SCANSTATUS builds. In this case, it sets or clears
2465 ** a flag that enables collection of the sqlite3_stmt_scanstatus_v2()
2466 ** statistics. For statistics to be collected, the flag must be set on
2467 ** the database handle both when the SQL statement is prepared and when it
2468 ** is stepped. The flag is set (collection of statistics is enabled)
2469 ** by default. This option takes two arguments: an integer and a pointer to
2470 ** an integer.. The first argument is 1, 0, or -1 to enable, disable, or
2471 ** leave unchanged the statement scanstatus option. If the second argument
2472 ** is not NULL, then the value of the statement scanstatus setting after
2473 ** processing the first argument is written into the integer that the second
2474 ** argument points to.
2477 ** [[SQLITE_DBCONFIG_REVERSE_SCANORDER]]
2478 ** <dt>SQLITE_DBCONFIG_REVERSE_SCANORDER</dt>
2479 ** <dd>The SQLITE_DBCONFIG_REVERSE_SCANORDER option changes the default order
2480 ** in which tables and indexes are scanned so that the scans start at the end
2481 ** and work toward the beginning rather than starting at the beginning and
2482 ** working toward the end. Setting SQLITE_DBCONFIG_REVERSE_SCANORDER is the
2483 ** same as setting [PRAGMA reverse_unordered_selects]. This option takes
2484 ** two arguments which are an integer and a pointer to an integer. The first
2485 ** argument is 1, 0, or -1 to enable, disable, or leave unchanged the
2486 ** reverse scan order flag, respectively. If the second argument is not NULL,
2487 ** then 0 or 1 is written into the integer that the second argument points to
2488 ** depending on if the reverse scan order flag is set after processing the
2494 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */
2495 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
2496 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
2497 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
2498 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
2499 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
2500 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */
2501 #define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */
2502 #define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */
2503 #define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */
2504 #define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */
2505 #define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */
2506 #define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */
2507 #define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */
2508 #define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */
2509 #define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */
2510 #define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */
2511 #define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */
2512 #define SQLITE_DBCONFIG_STMT_SCANSTATUS 1018 /* int int* */
2513 #define SQLITE_DBCONFIG_REVERSE_SCANORDER 1019 /* int int* */
2514 #define SQLITE_DBCONFIG_MAX 1019 /* Largest DBCONFIG */
2517 ** CAPI3REF: Enable Or Disable Extended Result Codes
2520 ** ^The sqlite3_extended_result_codes() routine enables or disables the
2521 ** [extended result codes] feature of SQLite. ^The extended result
2522 ** codes are disabled by default for historical compatibility.
2524 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
2527 ** CAPI3REF: Last Insert Rowid
2530 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
2531 ** has a unique 64-bit signed
2532 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available
2533 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
2534 ** names are not also used by explicitly declared columns. ^If
2535 ** the table has a column of type [INTEGER PRIMARY KEY] then that column
2536 ** is another alias for the rowid.
2538 ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of
2539 ** the most recent successful [INSERT] into a rowid table or [virtual table]
2540 ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not
2541 ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred
2542 ** on the database connection D, then sqlite3_last_insert_rowid(D) returns
2545 ** As well as being set automatically as rows are inserted into database
2546 ** tables, the value returned by this function may be set explicitly by
2547 ** [sqlite3_set_last_insert_rowid()]
2549 ** Some virtual table implementations may INSERT rows into rowid tables as
2550 ** part of committing a transaction (e.g. to flush data accumulated in memory
2551 ** to disk). In this case subsequent calls to this function return the rowid
2552 ** associated with these internal INSERT operations, which leads to
2553 ** unintuitive results. Virtual table implementations that do write to rowid
2554 ** tables in this way can avoid this problem by restoring the original
2555 ** rowid value using [sqlite3_set_last_insert_rowid()] before returning
2556 ** control to the user.
2558 ** ^(If an [INSERT] occurs within a trigger then this routine will
2559 ** return the [rowid] of the inserted row as long as the trigger is
2560 ** running. Once the trigger program ends, the value returned
2561 ** by this routine reverts to what it was before the trigger was fired.)^
2563 ** ^An [INSERT] that fails due to a constraint violation is not a
2564 ** successful [INSERT] and does not change the value returned by this
2565 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
2566 ** and INSERT OR ABORT make no changes to the return value of this
2567 ** routine when their insertion fails. ^(When INSERT OR REPLACE
2568 ** encounters a constraint violation, it does not fail. The
2569 ** INSERT continues to completion after deleting rows that caused
2570 ** the constraint problem so INSERT OR REPLACE will always change
2571 ** the return value of this interface.)^
2573 ** ^For the purposes of this routine, an [INSERT] is considered to
2574 ** be successful even if it is subsequently rolled back.
2576 ** This function is accessible to SQL statements via the
2577 ** [last_insert_rowid() SQL function].
2579 ** If a separate thread performs a new [INSERT] on the same
2580 ** database connection while the [sqlite3_last_insert_rowid()]
2581 ** function is running and thus changes the last insert [rowid],
2582 ** then the value returned by [sqlite3_last_insert_rowid()] is
2583 ** unpredictable and might not equal either the old or the new
2584 ** last insert [rowid].
2586 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
2589 ** CAPI3REF: Set the Last Insert Rowid value.
2592 ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to
2593 ** set the value returned by calling sqlite3_last_insert_rowid(D) to R
2594 ** without inserting a row into the database.
2596 SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64);
2599 ** CAPI3REF: Count The Number Of Rows Modified
2602 ** ^These functions return the number of rows modified, inserted or
2603 ** deleted by the most recently completed INSERT, UPDATE or DELETE
2604 ** statement on the database connection specified by the only parameter.
2605 ** The two functions are identical except for the type of the return value
2606 ** and that if the number of rows modified by the most recent INSERT, UPDATE
2607 ** or DELETE is greater than the maximum value supported by type "int", then
2608 ** the return value of sqlite3_changes() is undefined. ^Executing any other
2609 ** type of SQL statement does not modify the value returned by these functions.
2611 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
2612 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
2613 ** [foreign key actions] or [REPLACE] constraint resolution are not counted.
2615 ** Changes to a view that are intercepted by
2616 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
2617 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
2618 ** DELETE statement run on a view is always zero. Only changes made to real
2619 ** tables are counted.
2621 ** Things are more complicated if the sqlite3_changes() function is
2622 ** executed while a trigger program is running. This may happen if the
2623 ** program uses the [changes() SQL function], or if some other callback
2624 ** function invokes sqlite3_changes() directly. Essentially:
2627 ** <li> ^(Before entering a trigger program the value returned by
2628 ** sqlite3_changes() function is saved. After the trigger program
2629 ** has finished, the original value is restored.)^
2631 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
2632 ** statement sets the value returned by sqlite3_changes()
2633 ** upon completion as normal. Of course, this value will not include
2634 ** any changes performed by sub-triggers, as the sqlite3_changes()
2635 ** value will be saved and restored after each sub-trigger has run.)^
2638 ** ^This means that if the changes() SQL function (or similar) is used
2639 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it
2640 ** returns the value as set when the calling statement began executing.
2641 ** ^If it is used by the second or subsequent such statement within a trigger
2642 ** program, the value returned reflects the number of rows modified by the
2643 ** previous INSERT, UPDATE or DELETE statement within the same trigger.
2645 ** If a separate thread makes changes on the same database connection
2646 ** while [sqlite3_changes()] is running then the value returned
2647 ** is unpredictable and not meaningful.
2651 ** <li> the [sqlite3_total_changes()] interface
2652 ** <li> the [count_changes pragma]
2653 ** <li> the [changes() SQL function]
2654 ** <li> the [data_version pragma]
2657 SQLITE_API int sqlite3_changes(sqlite3*);
2658 SQLITE_API sqlite3_int64 sqlite3_changes64(sqlite3*);
2661 ** CAPI3REF: Total Number Of Rows Modified
2664 ** ^These functions return the total number of rows inserted, modified or
2665 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
2666 ** since the database connection was opened, including those executed as
2667 ** part of trigger programs. The two functions are identical except for the
2668 ** type of the return value and that if the number of rows modified by the
2669 ** connection exceeds the maximum value supported by type "int", then
2670 ** the return value of sqlite3_total_changes() is undefined. ^Executing
2671 ** any other type of SQL statement does not affect the value returned by
2672 ** sqlite3_total_changes().
2674 ** ^Changes made as part of [foreign key actions] are included in the
2675 ** count, but those made as part of REPLACE constraint resolution are
2676 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
2679 ** The [sqlite3_total_changes(D)] interface only reports the number
2680 ** of rows that changed due to SQL statement run against database
2681 ** connection D. Any changes by other database connections are ignored.
2682 ** To detect changes against a database file from other database
2683 ** connections use the [PRAGMA data_version] command or the
2684 ** [SQLITE_FCNTL_DATA_VERSION] [file control].
2686 ** If a separate thread makes changes on the same database connection
2687 ** while [sqlite3_total_changes()] is running then the value
2688 ** returned is unpredictable and not meaningful.
2692 ** <li> the [sqlite3_changes()] interface
2693 ** <li> the [count_changes pragma]
2694 ** <li> the [changes() SQL function]
2695 ** <li> the [data_version pragma]
2696 ** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control]
2699 SQLITE_API int sqlite3_total_changes(sqlite3*);
2700 SQLITE_API sqlite3_int64 sqlite3_total_changes64(sqlite3*);
2703 ** CAPI3REF: Interrupt A Long-Running Query
2706 ** ^This function causes any pending database operation to abort and
2707 ** return at its earliest opportunity. This routine is typically
2708 ** called in response to a user action such as pressing "Cancel"
2709 ** or Ctrl-C where the user wants a long query operation to halt
2712 ** ^It is safe to call this routine from a thread different from the
2713 ** thread that is currently running the database operation. But it
2714 ** is not safe to call this routine with a [database connection] that
2715 ** is closed or might close before sqlite3_interrupt() returns.
2717 ** ^If an SQL operation is very nearly finished at the time when
2718 ** sqlite3_interrupt() is called, then it might not have an opportunity
2719 ** to be interrupted and might continue to completion.
2721 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
2722 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
2723 ** that is inside an explicit transaction, then the entire transaction
2724 ** will be rolled back automatically.
2726 ** ^The sqlite3_interrupt(D) call is in effect until all currently running
2727 ** SQL statements on [database connection] D complete. ^Any new SQL statements
2728 ** that are started after the sqlite3_interrupt() call and before the
2729 ** running statement count reaches zero are interrupted as if they had been
2730 ** running prior to the sqlite3_interrupt() call. ^New SQL statements
2731 ** that are started after the running statement count reaches zero are
2732 ** not effected by the sqlite3_interrupt().
2733 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running
2734 ** SQL statements is a no-op and has no effect on SQL statements
2735 ** that are started after the sqlite3_interrupt() call returns.
2737 ** ^The [sqlite3_is_interrupted(D)] interface can be used to determine whether
2738 ** or not an interrupt is currently in effect for [database connection] D.
2739 ** It returns 1 if an interrupt is currently in effect, or 0 otherwise.
2741 SQLITE_API void sqlite3_interrupt(sqlite3*);
2742 SQLITE_API int sqlite3_is_interrupted(sqlite3*);
2745 ** CAPI3REF: Determine If An SQL Statement Is Complete
2747 ** These routines are useful during command-line input to determine if the
2748 ** currently entered text seems to form a complete SQL statement or
2749 ** if additional input is needed before sending the text into
2750 ** SQLite for parsing. ^These routines return 1 if the input string
2751 ** appears to be a complete SQL statement. ^A statement is judged to be
2752 ** complete if it ends with a semicolon token and is not a prefix of a
2753 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
2754 ** string literals or quoted identifier names or comments are not
2755 ** independent tokens (they are part of the token in which they are
2756 ** embedded) and thus do not count as a statement terminator. ^Whitespace
2757 ** and comments that follow the final semicolon are ignored.
2759 ** ^These routines return 0 if the statement is incomplete. ^If a
2760 ** memory allocation fails, then SQLITE_NOMEM is returned.
2762 ** ^These routines do not parse the SQL statements thus
2763 ** will not detect syntactically incorrect SQL.
2765 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
2766 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2767 ** automatically by sqlite3_complete16(). If that initialization fails,
2768 ** then the return value from sqlite3_complete16() will be non-zero
2769 ** regardless of whether or not the input SQL is complete.)^
2771 ** The input to [sqlite3_complete()] must be a zero-terminated
2774 ** The input to [sqlite3_complete16()] must be a zero-terminated
2775 ** UTF-16 string in native byte order.
2777 SQLITE_API int sqlite3_complete(const char *sql);
2778 SQLITE_API int sqlite3_complete16(const void *sql);
2781 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2782 ** KEYWORDS: {busy-handler callback} {busy handler}
2785 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
2786 ** that might be invoked with argument P whenever
2787 ** an attempt is made to access a database table associated with
2788 ** [database connection] D when another thread
2789 ** or process has the table locked.
2790 ** The sqlite3_busy_handler() interface is used to implement
2791 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
2793 ** ^If the busy callback is NULL, then [SQLITE_BUSY]
2794 ** is returned immediately upon encountering the lock. ^If the busy callback
2795 ** is not NULL, then the callback might be invoked with two arguments.
2797 ** ^The first argument to the busy handler is a copy of the void* pointer which
2798 ** is the third argument to sqlite3_busy_handler(). ^The second argument to
2799 ** the busy handler callback is the number of times that the busy handler has
2800 ** been invoked previously for the same locking event. ^If the
2801 ** busy callback returns 0, then no additional attempts are made to
2802 ** access the database and [SQLITE_BUSY] is returned
2803 ** to the application.
2804 ** ^If the callback returns non-zero, then another attempt
2805 ** is made to access the database and the cycle repeats.
2807 ** The presence of a busy handler does not guarantee that it will be invoked
2808 ** when there is lock contention. ^If SQLite determines that invoking the busy
2809 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
2810 ** to the application instead of invoking the
2812 ** Consider a scenario where one process is holding a read lock that
2813 ** it is trying to promote to a reserved lock and
2814 ** a second process is holding a reserved lock that it is trying
2815 ** to promote to an exclusive lock. The first process cannot proceed
2816 ** because it is blocked by the second and the second process cannot
2817 ** proceed because it is blocked by the first. If both processes
2818 ** invoke the busy handlers, neither will make any progress. Therefore,
2819 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
2820 ** will induce the first process to release its read lock and allow
2821 ** the second process to proceed.
2823 ** ^The default busy callback is NULL.
2825 ** ^(There can only be a single busy handler defined for each
2826 ** [database connection]. Setting a new busy handler clears any
2827 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
2828 ** or evaluating [PRAGMA busy_timeout=N] will change the
2829 ** busy handler and thus clear any previously set busy handler.
2831 ** The busy callback should not take any actions which modify the
2832 ** database connection that invoked the busy handler. In other words,
2833 ** the busy handler is not reentrant. Any such actions
2834 ** result in undefined behavior.
2836 ** A busy handler must not close the database connection
2837 ** or [prepared statement] that invoked the busy handler.
2839 SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*);
2842 ** CAPI3REF: Set A Busy Timeout
2845 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
2846 ** for a specified amount of time when a table is locked. ^The handler
2847 ** will sleep multiple times until at least "ms" milliseconds of sleeping
2848 ** have accumulated. ^After at least "ms" milliseconds of sleeping,
2849 ** the handler returns 0 which causes [sqlite3_step()] to return
2852 ** ^Calling this routine with an argument less than or equal to zero
2853 ** turns off all busy handlers.
2855 ** ^(There can only be a single busy handler for a particular
2856 ** [database connection] at any given moment. If another busy handler
2857 ** was defined (using [sqlite3_busy_handler()]) prior to calling
2858 ** this routine, that other busy handler is cleared.)^
2860 ** See also: [PRAGMA busy_timeout]
2862 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
2865 ** CAPI3REF: Convenience Routines For Running Queries
2868 ** This is a legacy interface that is preserved for backwards compatibility.
2869 ** Use of this interface is not recommended.
2871 ** Definition: A <b>result table</b> is memory data structure created by the
2872 ** [sqlite3_get_table()] interface. A result table records the
2873 ** complete query results from one or more queries.
2875 ** The table conceptually has a number of rows and columns. But
2876 ** these numbers are not part of the result table itself. These
2877 ** numbers are obtained separately. Let N be the number of rows
2878 ** and M be the number of columns.
2880 ** A result table is an array of pointers to zero-terminated UTF-8 strings.
2881 ** There are (N+1)*M elements in the array. The first M pointers point
2882 ** to zero-terminated strings that contain the names of the columns.
2883 ** The remaining entries all point to query results. NULL values result
2884 ** in NULL pointers. All other values are in their UTF-8 zero-terminated
2885 ** string representation as returned by [sqlite3_column_text()].
2887 ** A result table might consist of one or more memory allocations.
2888 ** It is not safe to pass a result table directly to [sqlite3_free()].
2889 ** A result table should be deallocated using [sqlite3_free_table()].
2891 ** ^(As an example of the result table format, suppose a query result
2894 ** <blockquote><pre>
2896 ** -----------------------
2900 ** </pre></blockquote>
2902 ** There are two columns (M==2) and three rows (N==3). Thus the
2903 ** result table has 8 entries. Suppose the result table is stored
2904 ** in an array named azResult. Then azResult holds this content:
2906 ** <blockquote><pre>
2907 ** azResult[0] = "Name";
2908 ** azResult[1] = "Age";
2909 ** azResult[2] = "Alice";
2910 ** azResult[3] = "43";
2911 ** azResult[4] = "Bob";
2912 ** azResult[5] = "28";
2913 ** azResult[6] = "Cindy";
2914 ** azResult[7] = "21";
2915 ** </pre></blockquote>)^
2917 ** ^The sqlite3_get_table() function evaluates one or more
2918 ** semicolon-separated SQL statements in the zero-terminated UTF-8
2919 ** string of its 2nd parameter and returns a result table to the
2920 ** pointer given in its 3rd parameter.
2922 ** After the application has finished with the result from sqlite3_get_table(),
2923 ** it must pass the result table pointer to sqlite3_free_table() in order to
2924 ** release the memory that was malloced. Because of the way the
2925 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
2926 ** function must not try to call [sqlite3_free()] directly. Only
2927 ** [sqlite3_free_table()] is able to release the memory properly and safely.
2929 ** The sqlite3_get_table() interface is implemented as a wrapper around
2930 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
2931 ** to any internal data structures of SQLite. It uses only the public
2932 ** interface defined here. As a consequence, errors that occur in the
2933 ** wrapper layer outside of the internal [sqlite3_exec()] call are not
2934 ** reflected in subsequent calls to [sqlite3_errcode()] or
2935 ** [sqlite3_errmsg()].
2937 SQLITE_API int sqlite3_get_table(
2938 sqlite3 *db, /* An open database */
2939 const char *zSql, /* SQL to be evaluated */
2940 char ***pazResult, /* Results of the query */
2941 int *pnRow, /* Number of result rows written here */
2942 int *pnColumn, /* Number of result columns written here */
2943 char **pzErrmsg /* Error msg written here */
2945 SQLITE_API void sqlite3_free_table(char **result);
2948 ** CAPI3REF: Formatted String Printing Functions
2950 ** These routines are work-alikes of the "printf()" family of functions
2951 ** from the standard C library.
2952 ** These routines understand most of the common formatting options from
2953 ** the standard library printf()
2954 ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]).
2955 ** See the [built-in printf()] documentation for details.
2957 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
2958 ** results into memory obtained from [sqlite3_malloc64()].
2959 ** The strings returned by these two routines should be
2960 ** released by [sqlite3_free()]. ^Both routines return a
2961 ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough
2962 ** memory to hold the resulting string.
2964 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
2965 ** the standard C library. The result is written into the
2966 ** buffer supplied as the second parameter whose size is given by
2967 ** the first parameter. Note that the order of the
2968 ** first two parameters is reversed from snprintf().)^ This is an
2969 ** historical accident that cannot be fixed without breaking
2970 ** backwards compatibility. ^(Note also that sqlite3_snprintf()
2971 ** returns a pointer to its buffer instead of the number of
2972 ** characters actually written into the buffer.)^ We admit that
2973 ** the number of characters written would be a more useful return
2974 ** value but we cannot change the implementation of sqlite3_snprintf()
2975 ** now without breaking compatibility.
2977 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
2978 ** guarantees that the buffer is always zero-terminated. ^The first
2979 ** parameter "n" is the total size of the buffer, including space for
2980 ** the zero terminator. So the longest string that can be completely
2981 ** written will be n-1 characters.
2983 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
2985 ** See also: [built-in printf()], [printf() SQL function]
2987 SQLITE_API char *sqlite3_mprintf(const char*,...);
2988 SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
2989 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
2990 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
2993 ** CAPI3REF: Memory Allocation Subsystem
2995 ** The SQLite core uses these three routines for all of its own
2996 ** internal memory allocation needs. "Core" in the previous sentence
2997 ** does not include operating-system specific [VFS] implementation. The
2998 ** Windows VFS uses native malloc() and free() for some operations.
3000 ** ^The sqlite3_malloc() routine returns a pointer to a block
3001 ** of memory at least N bytes in length, where N is the parameter.
3002 ** ^If sqlite3_malloc() is unable to obtain sufficient free
3003 ** memory, it returns a NULL pointer. ^If the parameter N to
3004 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
3007 ** ^The sqlite3_malloc64(N) routine works just like
3008 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
3009 ** of a signed 32-bit integer.
3011 ** ^Calling sqlite3_free() with a pointer previously returned
3012 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
3013 ** that it might be reused. ^The sqlite3_free() routine is
3014 ** a no-op if is called with a NULL pointer. Passing a NULL pointer
3015 ** to sqlite3_free() is harmless. After being freed, memory
3016 ** should neither be read nor written. Even reading previously freed
3017 ** memory might result in a segmentation fault or other severe error.
3018 ** Memory corruption, a segmentation fault, or other severe error
3019 ** might result if sqlite3_free() is called with a non-NULL pointer that
3020 ** was not obtained from sqlite3_malloc() or sqlite3_realloc().
3022 ** ^The sqlite3_realloc(X,N) interface attempts to resize a
3023 ** prior memory allocation X to be at least N bytes.
3024 ** ^If the X parameter to sqlite3_realloc(X,N)
3025 ** is a NULL pointer then its behavior is identical to calling
3026 ** sqlite3_malloc(N).
3027 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or
3028 ** negative then the behavior is exactly the same as calling
3030 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
3031 ** of at least N bytes in size or NULL if insufficient memory is available.
3032 ** ^If M is the size of the prior allocation, then min(N,M) bytes
3033 ** of the prior allocation are copied into the beginning of buffer returned
3034 ** by sqlite3_realloc(X,N) and the prior allocation is freed.
3035 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
3036 ** prior allocation is not freed.
3038 ** ^The sqlite3_realloc64(X,N) interfaces works the same as
3039 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
3040 ** of a 32-bit signed integer.
3042 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
3043 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
3044 ** sqlite3_msize(X) returns the size of that memory allocation in bytes.
3045 ** ^The value returned by sqlite3_msize(X) might be larger than the number
3046 ** of bytes requested when X was allocated. ^If X is a NULL pointer then
3047 ** sqlite3_msize(X) returns zero. If X points to something that is not
3048 ** the beginning of memory allocation, or if it points to a formerly
3049 ** valid memory allocation that has now been freed, then the behavior
3050 ** of sqlite3_msize(X) is undefined and possibly harmful.
3052 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
3053 ** sqlite3_malloc64(), and sqlite3_realloc64()
3054 ** is always aligned to at least an 8 byte boundary, or to a
3055 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
3058 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
3059 ** must be either NULL or else pointers obtained from a prior
3060 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
3061 ** not yet been released.
3063 ** The application must not read or write any part of
3064 ** a block of memory after it has been released using
3065 ** [sqlite3_free()] or [sqlite3_realloc()].
3067 SQLITE_API void *sqlite3_malloc(int);
3068 SQLITE_API void *sqlite3_malloc64(sqlite3_uint64);
3069 SQLITE_API void *sqlite3_realloc(void*, int);
3070 SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64);
3071 SQLITE_API void sqlite3_free(void*);
3072 SQLITE_API sqlite3_uint64 sqlite3_msize(void*);
3075 ** CAPI3REF: Memory Allocator Statistics
3077 ** SQLite provides these two interfaces for reporting on the status
3078 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
3079 ** routines, which form the built-in memory allocation subsystem.
3081 ** ^The [sqlite3_memory_used()] routine returns the number of bytes
3082 ** of memory currently outstanding (malloced but not freed).
3083 ** ^The [sqlite3_memory_highwater()] routine returns the maximum
3084 ** value of [sqlite3_memory_used()] since the high-water mark
3085 ** was last reset. ^The values returned by [sqlite3_memory_used()] and
3086 ** [sqlite3_memory_highwater()] include any overhead
3087 ** added by SQLite in its implementation of [sqlite3_malloc()],
3088 ** but not overhead added by the any underlying system library
3089 ** routines that [sqlite3_malloc()] may call.
3091 ** ^The memory high-water mark is reset to the current value of
3092 ** [sqlite3_memory_used()] if and only if the parameter to
3093 ** [sqlite3_memory_highwater()] is true. ^The value returned
3094 ** by [sqlite3_memory_highwater(1)] is the high-water mark
3095 ** prior to the reset.
3097 SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
3098 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
3101 ** CAPI3REF: Pseudo-Random Number Generator
3103 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
3104 ** select random [ROWID | ROWIDs] when inserting new records into a table that
3105 ** already uses the largest possible [ROWID]. The PRNG is also used for
3106 ** the built-in random() and randomblob() SQL functions. This interface allows
3107 ** applications to access the same PRNG for other purposes.
3109 ** ^A call to this routine stores N bytes of randomness into buffer P.
3110 ** ^The P parameter can be a NULL pointer.
3112 ** ^If this routine has not been previously called or if the previous
3113 ** call had N less than one or a NULL pointer for P, then the PRNG is
3114 ** seeded using randomness obtained from the xRandomness method of
3115 ** the default [sqlite3_vfs] object.
3116 ** ^If the previous call to this routine had an N of 1 or more and a
3117 ** non-NULL P then the pseudo-randomness is generated
3118 ** internally and without recourse to the [sqlite3_vfs] xRandomness
3121 SQLITE_API void sqlite3_randomness(int N, void *P);
3124 ** CAPI3REF: Compile-Time Authorization Callbacks
3126 ** KEYWORDS: {authorizer callback}
3128 ** ^This routine registers an authorizer callback with a particular
3129 ** [database connection], supplied in the first argument.
3130 ** ^The authorizer callback is invoked as SQL statements are being compiled
3131 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
3132 ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()],
3133 ** and [sqlite3_prepare16_v3()]. ^At various
3134 ** points during the compilation process, as logic is being created
3135 ** to perform various actions, the authorizer callback is invoked to
3136 ** see if those actions are allowed. ^The authorizer callback should
3137 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
3138 ** specific action but allow the SQL statement to continue to be
3139 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
3140 ** rejected with an error. ^If the authorizer callback returns
3141 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
3142 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered
3143 ** the authorizer will fail with an error message.
3145 ** When the callback returns [SQLITE_OK], that means the operation
3146 ** requested is ok. ^When the callback returns [SQLITE_DENY], the
3147 ** [sqlite3_prepare_v2()] or equivalent call that triggered the
3148 ** authorizer will fail with an error message explaining that
3149 ** access is denied.
3151 ** ^The first parameter to the authorizer callback is a copy of the third
3152 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
3153 ** to the callback is an integer [SQLITE_COPY | action code] that specifies
3154 ** the particular action to be authorized. ^The third through sixth parameters
3155 ** to the callback are either NULL pointers or zero-terminated strings
3156 ** that contain additional details about the action to be authorized.
3157 ** Applications must always be prepared to encounter a NULL pointer in any
3158 ** of the third through the sixth parameters of the authorization callback.
3160 ** ^If the action code is [SQLITE_READ]
3161 ** and the callback returns [SQLITE_IGNORE] then the
3162 ** [prepared statement] statement is constructed to substitute
3163 ** a NULL value in place of the table column that would have
3164 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
3165 ** return can be used to deny an untrusted user access to individual
3166 ** columns of a table.
3167 ** ^When a table is referenced by a [SELECT] but no column values are
3168 ** extracted from that table (for example in a query like
3169 ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback
3170 ** is invoked once for that table with a column name that is an empty string.
3171 ** ^If the action code is [SQLITE_DELETE] and the callback returns
3172 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
3173 ** [truncate optimization] is disabled and all rows are deleted individually.
3175 ** An authorizer is used when [sqlite3_prepare | preparing]
3176 ** SQL statements from an untrusted source, to ensure that the SQL statements
3177 ** do not try to access data they are not allowed to see, or that they do not
3178 ** try to execute malicious statements that damage the database. For
3179 ** example, an application may allow a user to enter arbitrary
3180 ** SQL queries for evaluation by a database. But the application does
3181 ** not want the user to be able to make arbitrary changes to the
3182 ** database. An authorizer could then be put in place while the
3183 ** user-entered SQL is being [sqlite3_prepare | prepared] that
3184 ** disallows everything except [SELECT] statements.
3186 ** Applications that need to process SQL from untrusted sources
3187 ** might also consider lowering resource limits using [sqlite3_limit()]
3188 ** and limiting database size using the [max_page_count] [PRAGMA]
3189 ** in addition to using an authorizer.
3191 ** ^(Only a single authorizer can be in place on a database connection
3192 ** at a time. Each call to sqlite3_set_authorizer overrides the
3193 ** previous call.)^ ^Disable the authorizer by installing a NULL callback.
3194 ** The authorizer is disabled by default.
3196 ** The authorizer callback must not do anything that will modify
3197 ** the database connection that invoked the authorizer callback.
3198 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3199 ** database connections for the meaning of "modify" in this paragraph.
3201 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
3202 ** statement might be re-prepared during [sqlite3_step()] due to a
3203 ** schema change. Hence, the application should ensure that the
3204 ** correct authorizer callback remains in place during the [sqlite3_step()].
3206 ** ^Note that the authorizer callback is invoked only during
3207 ** [sqlite3_prepare()] or its variants. Authorization is not
3208 ** performed during statement evaluation in [sqlite3_step()], unless
3209 ** as stated in the previous paragraph, sqlite3_step() invokes
3210 ** sqlite3_prepare_v2() to reprepare a statement after a schema change.
3212 SQLITE_API int sqlite3_set_authorizer(
3214 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
3219 ** CAPI3REF: Authorizer Return Codes
3221 ** The [sqlite3_set_authorizer | authorizer callback function] must
3222 ** return either [SQLITE_OK] or one of these two constants in order
3223 ** to signal SQLite whether or not the action is permitted. See the
3224 ** [sqlite3_set_authorizer | authorizer documentation] for additional
3227 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
3228 ** returned from the [sqlite3_vtab_on_conflict()] interface.
3230 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */
3231 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
3234 ** CAPI3REF: Authorizer Action Codes
3236 ** The [sqlite3_set_authorizer()] interface registers a callback function
3237 ** that is invoked to authorize certain SQL statement actions. The
3238 ** second parameter to the callback is an integer code that specifies
3239 ** what action is being authorized. These are the integer action codes that
3240 ** the authorizer callback may be passed.
3242 ** These action code values signify what kind of operation is to be
3243 ** authorized. The 3rd and 4th parameters to the authorization
3244 ** callback function will be parameters or NULL depending on which of these
3245 ** codes is used as the second parameter. ^(The 5th parameter to the
3246 ** authorizer callback is the name of the database ("main", "temp",
3247 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
3248 ** is the name of the inner-most trigger or view that is responsible for
3249 ** the access attempt or NULL if this access attempt is directly from
3250 ** top-level SQL code.
3252 /******************************************* 3rd ************ 4th ***********/
3253 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
3254 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
3255 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
3256 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
3257 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
3258 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
3259 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
3260 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */
3261 #define SQLITE_DELETE 9 /* Table Name NULL */
3262 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
3263 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */
3264 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
3265 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
3266 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
3267 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
3268 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
3269 #define SQLITE_DROP_VIEW 17 /* View Name NULL */
3270 #define SQLITE_INSERT 18 /* Table Name NULL */
3271 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
3272 #define SQLITE_READ 20 /* Table Name Column Name */
3273 #define SQLITE_SELECT 21 /* NULL NULL */
3274 #define SQLITE_TRANSACTION 22 /* Operation NULL */
3275 #define SQLITE_UPDATE 23 /* Table Name Column Name */
3276 #define SQLITE_ATTACH 24 /* Filename NULL */
3277 #define SQLITE_DETACH 25 /* Database Name NULL */
3278 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
3279 #define SQLITE_REINDEX 27 /* Index Name NULL */
3280 #define SQLITE_ANALYZE 28 /* Table Name NULL */
3281 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
3282 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
3283 #define SQLITE_FUNCTION 31 /* NULL Function Name */
3284 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
3285 #define SQLITE_COPY 0 /* No longer used */
3286 #define SQLITE_RECURSIVE 33 /* NULL NULL */
3289 ** CAPI3REF: Tracing And Profiling Functions
3292 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface
3293 ** instead of the routines described here.
3295 ** These routines register callback functions that can be used for
3296 ** tracing and profiling the execution of SQL statements.
3298 ** ^The callback function registered by sqlite3_trace() is invoked at
3299 ** various times when an SQL statement is being run by [sqlite3_step()].
3300 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
3301 ** SQL statement text as the statement first begins executing.
3302 ** ^(Additional sqlite3_trace() callbacks might occur
3303 ** as each triggered subprogram is entered. The callbacks for triggers
3304 ** contain a UTF-8 SQL comment that identifies the trigger.)^
3306 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
3307 ** the length of [bound parameter] expansion in the output of sqlite3_trace().
3309 ** ^The callback function registered by sqlite3_profile() is invoked
3310 ** as each SQL statement finishes. ^The profile callback contains
3311 ** the original statement text and an estimate of wall-clock time
3312 ** of how long that statement took to run. ^The profile callback
3313 ** time is in units of nanoseconds, however the current implementation
3314 ** is only capable of millisecond resolution so the six least significant
3315 ** digits in the time are meaningless. Future versions of SQLite
3316 ** might provide greater resolution on the profiler callback. Invoking
3317 ** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the
3318 ** profile callback.
3320 SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*,
3321 void(*xTrace)(void*,const char*), void*);
3322 SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*,
3323 void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
3326 ** CAPI3REF: SQL Trace Event Codes
3327 ** KEYWORDS: SQLITE_TRACE
3329 ** These constants identify classes of events that can be monitored
3330 ** using the [sqlite3_trace_v2()] tracing logic. The M argument
3331 ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of
3332 ** the following constants. ^The first argument to the trace callback
3333 ** is one of the following constants.
3335 ** New tracing constants may be added in future releases.
3337 ** ^A trace callback has four arguments: xCallback(T,C,P,X).
3338 ** ^The T argument is one of the integer type codes above.
3339 ** ^The C argument is a copy of the context pointer passed in as the
3340 ** fourth argument to [sqlite3_trace_v2()].
3341 ** The P and X arguments are pointers whose meanings depend on T.
3344 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt>
3345 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement
3346 ** first begins running and possibly at other times during the
3347 ** execution of the prepared statement, such as at the start of each
3348 ** trigger subprogram. ^The P argument is a pointer to the
3349 ** [prepared statement]. ^The X argument is a pointer to a string which
3350 ** is the unexpanded SQL text of the prepared statement or an SQL comment
3351 ** that indicates the invocation of a trigger. ^The callback can compute
3352 ** the same text that would have been returned by the legacy [sqlite3_trace()]
3353 ** interface by using the X argument when X begins with "--" and invoking
3354 ** [sqlite3_expanded_sql(P)] otherwise.
3356 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt>
3357 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same
3358 ** information as is provided by the [sqlite3_profile()] callback.
3359 ** ^The P argument is a pointer to the [prepared statement] and the
3360 ** X argument points to a 64-bit integer which is approximately
3361 ** the number of nanoseconds that the prepared statement took to run.
3362 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.
3364 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt>
3365 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared
3366 ** statement generates a single row of result.
3367 ** ^The P argument is a pointer to the [prepared statement] and the
3368 ** X argument is unused.
3370 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt>
3371 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database
3372 ** connection closes.
3373 ** ^The P argument is a pointer to the [database connection] object
3374 ** and the X argument is unused.
3377 #define SQLITE_TRACE_STMT 0x01
3378 #define SQLITE_TRACE_PROFILE 0x02
3379 #define SQLITE_TRACE_ROW 0x04
3380 #define SQLITE_TRACE_CLOSE 0x08
3383 ** CAPI3REF: SQL Trace Hook
3386 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback
3387 ** function X against [database connection] D, using property mask M
3388 ** and context pointer P. ^If the X callback is
3389 ** NULL or if the M mask is zero, then tracing is disabled. The
3390 ** M argument should be the bitwise OR-ed combination of
3391 ** zero or more [SQLITE_TRACE] constants.
3393 ** ^Each call to either sqlite3_trace(D,X,P) or sqlite3_trace_v2(D,M,X,P)
3394 ** overrides (cancels) all prior calls to sqlite3_trace(D,X,P) or
3395 ** sqlite3_trace_v2(D,M,X,P) for the [database connection] D. Each
3396 ** database connection may have at most one trace callback.
3398 ** ^The X callback is invoked whenever any of the events identified by
3399 ** mask M occur. ^The integer return value from the callback is currently
3400 ** ignored, though this may change in future releases. Callback
3401 ** implementations should return zero to ensure future compatibility.
3403 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X).
3404 ** ^The T argument is one of the [SQLITE_TRACE]
3405 ** constants to indicate why the callback was invoked.
3406 ** ^The C argument is a copy of the context pointer.
3407 ** The P and X arguments are pointers whose meanings depend on T.
3409 ** The sqlite3_trace_v2() interface is intended to replace the legacy
3410 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which
3413 SQLITE_API int sqlite3_trace_v2(
3416 int(*xCallback)(unsigned,void*,void*,void*),
3421 ** CAPI3REF: Query Progress Callbacks
3424 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
3425 ** function X to be invoked periodically during long running calls to
3426 ** [sqlite3_step()] and [sqlite3_prepare()] and similar for
3427 ** database connection D. An example use for this
3428 ** interface is to keep a GUI updated during a large query.
3430 ** ^The parameter P is passed through as the only parameter to the
3431 ** callback function X. ^The parameter N is the approximate number of
3432 ** [virtual machine instructions] that are evaluated between successive
3433 ** invocations of the callback X. ^If N is less than one then the progress
3434 ** handler is disabled.
3436 ** ^Only a single progress handler may be defined at one time per
3437 ** [database connection]; setting a new progress handler cancels the
3438 ** old one. ^Setting parameter X to NULL disables the progress handler.
3439 ** ^The progress handler is also disabled by setting N to a value less
3442 ** ^If the progress callback returns non-zero, the operation is
3443 ** interrupted. This feature can be used to implement a
3444 ** "Cancel" button on a GUI progress dialog box.
3446 ** The progress handler callback must not do anything that will modify
3447 ** the database connection that invoked the progress handler.
3448 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3449 ** database connections for the meaning of "modify" in this paragraph.
3451 ** The progress handler callback would originally only be invoked from the
3452 ** bytecode engine. It still might be invoked during [sqlite3_prepare()]
3453 ** and similar because those routines might force a reparse of the schema
3454 ** which involves running the bytecode engine. However, beginning with
3455 ** SQLite version 3.41.0, the progress handler callback might also be
3456 ** invoked directly from [sqlite3_prepare()] while analyzing and generating
3457 ** code for complex queries.
3459 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
3462 ** CAPI3REF: Opening A New Database Connection
3463 ** CONSTRUCTOR: sqlite3
3465 ** ^These routines open an SQLite database file as specified by the
3466 ** filename argument. ^The filename argument is interpreted as UTF-8 for
3467 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
3468 ** order for sqlite3_open16(). ^(A [database connection] handle is usually
3469 ** returned in *ppDb, even if an error occurs. The only exception is that
3470 ** if SQLite is unable to allocate memory to hold the [sqlite3] object,
3471 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
3472 ** object.)^ ^(If the database is opened (and/or created) successfully, then
3473 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
3474 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
3475 ** an English language description of the error following a failure of any
3476 ** of the sqlite3_open() routines.
3478 ** ^The default encoding will be UTF-8 for databases created using
3479 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases
3480 ** created using sqlite3_open16() will be UTF-16 in the native byte order.
3482 ** Whether or not an error occurs when it is opened, resources
3483 ** associated with the [database connection] handle should be released by
3484 ** passing it to [sqlite3_close()] when it is no longer required.
3486 ** The sqlite3_open_v2() interface works like sqlite3_open()
3487 ** except that it accepts two additional parameters for additional control
3488 ** over the new database connection. ^(The flags parameter to
3489 ** sqlite3_open_v2() must include, at a minimum, one of the following
3490 ** three flag combinations:)^
3493 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
3494 ** <dd>The database is opened in read-only mode. If the database does
3495 ** not already exist, an error is returned.</dd>)^
3497 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
3498 ** <dd>The database is opened for reading and writing if possible, or
3499 ** reading only if the file is write protected by the operating
3500 ** system. In either case the database must already exist, otherwise
3501 ** an error is returned. For historical reasons, if opening in
3502 ** read-write mode fails due to OS-level permissions, an attempt is
3503 ** made to open it in read-only mode. [sqlite3_db_readonly()] can be
3504 ** used to determine whether the database is actually
3505 ** read-write.</dd>)^
3507 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
3508 ** <dd>The database is opened for reading and writing, and is created if
3509 ** it does not already exist. This is the behavior that is always used for
3510 ** sqlite3_open() and sqlite3_open16().</dd>)^
3513 ** In addition to the required flags, the following optional flags are
3517 ** ^(<dt>[SQLITE_OPEN_URI]</dt>
3518 ** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^
3520 ** ^(<dt>[SQLITE_OPEN_MEMORY]</dt>
3521 ** <dd>The database will be opened as an in-memory database. The database
3522 ** is named by the "filename" argument for the purposes of cache-sharing,
3523 ** if shared cache mode is enabled, but the "filename" is otherwise ignored.
3526 ** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt>
3527 ** <dd>The new database connection will use the "multi-thread"
3528 ** [threading mode].)^ This means that separate threads are allowed
3529 ** to use SQLite at the same time, as long as each thread is using
3530 ** a different [database connection].
3532 ** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt>
3533 ** <dd>The new database connection will use the "serialized"
3534 ** [threading mode].)^ This means the multiple threads can safely
3535 ** attempt to use the same database connection at the same time.
3536 ** (Mutexes will block any actual concurrency, but in this mode
3537 ** there is no harm in trying.)
3539 ** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt>
3540 ** <dd>The database is opened [shared cache] enabled, overriding
3541 ** the default shared cache setting provided by
3542 ** [sqlite3_enable_shared_cache()].)^
3543 ** The [use of shared cache mode is discouraged] and hence shared cache
3544 ** capabilities may be omitted from many builds of SQLite. In such cases,
3545 ** this option is a no-op.
3547 ** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt>
3548 ** <dd>The database is opened [shared cache] disabled, overriding
3549 ** the default shared cache setting provided by
3550 ** [sqlite3_enable_shared_cache()].)^
3552 ** [[OPEN_EXRESCODE]] ^(<dt>[SQLITE_OPEN_EXRESCODE]</dt>
3553 ** <dd>The database connection comes up in "extended result code mode".
3554 ** In other words, the database behaves has if
3555 ** [sqlite3_extended_result_codes(db,1)] where called on the database
3556 ** connection as soon as the connection is created. In addition to setting
3557 ** the extended result code mode, this flag also causes [sqlite3_open_v2()]
3558 ** to return an extended result code.</dd>
3560 ** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt>
3561 ** <dd>The database filename is not allowed to contain a symbolic link</dd>
3564 ** If the 3rd parameter to sqlite3_open_v2() is not one of the
3565 ** required combinations shown above optionally combined with other
3566 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
3567 ** then the behavior is undefined. Historic versions of SQLite
3568 ** have silently ignored surplus bits in the flags parameter to
3569 ** sqlite3_open_v2(), however that behavior might not be carried through
3570 ** into future versions of SQLite and so applications should not rely
3571 ** upon it. Note in particular that the SQLITE_OPEN_EXCLUSIVE flag is a no-op
3572 ** for sqlite3_open_v2(). The SQLITE_OPEN_EXCLUSIVE does *not* cause
3573 ** the open to fail if the database already exists. The SQLITE_OPEN_EXCLUSIVE
3574 ** flag is intended for use by the [sqlite3_vfs|VFS interface] only, and not
3575 ** by sqlite3_open_v2().
3577 ** ^The fourth parameter to sqlite3_open_v2() is the name of the
3578 ** [sqlite3_vfs] object that defines the operating system interface that
3579 ** the new database connection should use. ^If the fourth parameter is
3580 ** a NULL pointer then the default [sqlite3_vfs] object is used.
3582 ** ^If the filename is ":memory:", then a private, temporary in-memory database
3583 ** is created for the connection. ^This in-memory database will vanish when
3584 ** the database connection is closed. Future versions of SQLite might
3585 ** make use of additional special filenames that begin with the ":" character.
3586 ** It is recommended that when a database filename actually does begin with
3587 ** a ":" character you should prefix the filename with a pathname such as
3588 ** "./" to avoid ambiguity.
3590 ** ^If the filename is an empty string, then a private, temporary
3591 ** on-disk database will be created. ^This private database will be
3592 ** automatically deleted as soon as the database connection is closed.
3594 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
3596 ** ^If [URI filename] interpretation is enabled, and the filename argument
3597 ** begins with "file:", then the filename is interpreted as a URI. ^URI
3598 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
3599 ** set in the third argument to sqlite3_open_v2(), or if it has
3600 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the
3601 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
3602 ** URI filename interpretation is turned off
3603 ** by default, but future releases of SQLite might enable URI filename
3604 ** interpretation by default. See "[URI filenames]" for additional
3607 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an
3608 ** authority, then it must be either an empty string or the string
3609 ** "localhost". ^If the authority is not an empty string or "localhost", an
3610 ** error is returned to the caller. ^The fragment component of a URI, if
3611 ** present, is ignored.
3613 ** ^SQLite uses the path component of the URI as the name of the disk file
3614 ** which contains the database. ^If the path begins with a '/' character,
3615 ** then it is interpreted as an absolute path. ^If the path does not begin
3616 ** with a '/' (meaning that the authority section is omitted from the URI)
3617 ** then the path is interpreted as a relative path.
3618 ** ^(On windows, the first component of an absolute path
3619 ** is a drive specification (e.g. "C:").)^
3621 ** [[core URI query parameters]]
3622 ** The query component of a URI may contain parameters that are interpreted
3623 ** either by SQLite itself, or by a [VFS | custom VFS implementation].
3624 ** SQLite and its built-in [VFSes] interpret the
3625 ** following query parameters:
3628 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
3629 ** a VFS object that provides the operating system interface that should
3630 ** be used to access the database file on disk. ^If this option is set to
3631 ** an empty string the default VFS object is used. ^Specifying an unknown
3632 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
3633 ** present, then the VFS specified by the option takes precedence over
3634 ** the value passed as the fourth parameter to sqlite3_open_v2().
3636 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
3637 ** "rwc", or "memory". Attempting to set it to any other value is
3639 ** ^If "ro" is specified, then the database is opened for read-only
3640 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
3641 ** third argument to sqlite3_open_v2(). ^If the mode option is set to
3642 ** "rw", then the database is opened for read-write (but not create)
3643 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
3644 ** been set. ^Value "rwc" is equivalent to setting both
3645 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
3646 ** set to "memory" then a pure [in-memory database] that never reads
3647 ** or writes from disk is used. ^It is an error to specify a value for
3648 ** the mode parameter that is less restrictive than that specified by
3649 ** the flags passed in the third parameter to sqlite3_open_v2().
3651 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
3652 ** "private". ^Setting it to "shared" is equivalent to setting the
3653 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
3654 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
3655 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
3656 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
3657 ** a URI filename, its value overrides any behavior requested by setting
3658 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
3660 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the
3661 ** [powersafe overwrite] property does or does not apply to the
3662 ** storage media on which the database file resides.
3664 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
3665 ** which if set disables file locking in rollback journal modes. This
3666 ** is useful for accessing a database on a filesystem that does not
3667 ** support locking. Caution: Database corruption might result if two
3668 ** or more processes write to the same database and any one of those
3669 ** processes uses nolock=1.
3671 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query
3672 ** parameter that indicates that the database file is stored on
3673 ** read-only media. ^When immutable is set, SQLite assumes that the
3674 ** database file cannot be changed, even by a process with higher
3675 ** privilege, and so the database is opened read-only and all locking
3676 ** and change detection is disabled. Caution: Setting the immutable
3677 ** property on a database file that does in fact change can result
3678 ** in incorrect query results and/or [SQLITE_CORRUPT] errors.
3679 ** See also: [SQLITE_IOCAP_IMMUTABLE].
3683 ** ^Specifying an unknown parameter in the query component of a URI is not an
3684 ** error. Future versions of SQLite might understand additional query
3685 ** parameters. See "[query parameters with special meaning to SQLite]" for
3686 ** additional information.
3688 ** [[URI filename examples]] <h3>URI filename examples</h3>
3690 ** <table border="1" align=center cellpadding=5>
3691 ** <tr><th> URI filenames <th> Results
3692 ** <tr><td> file:data.db <td>
3693 ** Open the file "data.db" in the current directory.
3694 ** <tr><td> file:/home/fred/data.db<br>
3695 ** file:///home/fred/data.db <br>
3696 ** file://localhost/home/fred/data.db <br> <td>
3697 ** Open the database file "/home/fred/data.db".
3698 ** <tr><td> file://darkstar/home/fred/data.db <td>
3699 ** An error. "darkstar" is not a recognized authority.
3700 ** <tr><td style="white-space:nowrap">
3701 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
3702 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive
3703 ** C:. Note that the %20 escaping in this example is not strictly
3704 ** necessary - space characters can be used literally
3705 ** in URI filenames.
3706 ** <tr><td> file:data.db?mode=ro&cache=private <td>
3707 ** Open file "data.db" in the current directory for read-only access.
3708 ** Regardless of whether or not shared-cache mode is enabled by
3709 ** default, use a private cache.
3710 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
3711 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
3712 ** that uses dot-files in place of posix advisory locking.
3713 ** <tr><td> file:data.db?mode=readonly <td>
3714 ** An error. "readonly" is not a valid option for the "mode" parameter.
3715 ** Use "ro" instead: "file:data.db?mode=ro".
3718 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and
3719 ** query components of a URI. A hexadecimal escape sequence consists of a
3720 ** percent sign - "%" - followed by exactly two hexadecimal digits
3721 ** specifying an octet value. ^Before the path or query components of a
3722 ** URI filename are interpreted, they are encoded using UTF-8 and all
3723 ** hexadecimal escape sequences replaced by a single byte containing the
3724 ** corresponding octet. If this process generates an invalid UTF-8 encoding,
3725 ** the results are undefined.
3727 ** <b>Note to Windows users:</b> The encoding used for the filename argument
3728 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
3729 ** codepage is currently defined. Filenames containing international
3730 ** characters must be converted to UTF-8 prior to passing them into
3731 ** sqlite3_open() or sqlite3_open_v2().
3733 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set
3734 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
3735 ** features that require the use of temporary files may fail.
3737 ** See also: [sqlite3_temp_directory]
3739 SQLITE_API int sqlite3_open(
3740 const char *filename, /* Database filename (UTF-8) */
3741 sqlite3 **ppDb /* OUT: SQLite db handle */
3743 SQLITE_API int sqlite3_open16(
3744 const void *filename, /* Database filename (UTF-16) */
3745 sqlite3 **ppDb /* OUT: SQLite db handle */
3747 SQLITE_API int sqlite3_open_v2(
3748 const char *filename, /* Database filename (UTF-8) */
3749 sqlite3 **ppDb, /* OUT: SQLite db handle */
3750 int flags, /* Flags */
3751 const char *zVfs /* Name of VFS module to use */
3755 ** CAPI3REF: Obtain Values For URI Parameters
3757 ** These are utility routines, useful to [VFS|custom VFS implementations],
3758 ** that check if a database file was a URI that contained a specific query
3759 ** parameter, and if so obtains the value of that query parameter.
3761 ** The first parameter to these interfaces (hereafter referred to
3762 ** as F) must be one of:
3764 ** <li> A database filename pointer created by the SQLite core and
3765 ** passed into the xOpen() method of a VFS implementation, or
3766 ** <li> A filename obtained from [sqlite3_db_filename()], or
3767 ** <li> A new filename constructed using [sqlite3_create_filename()].
3769 ** If the F parameter is not one of the above, then the behavior is
3770 ** undefined and probably undesirable. Older versions of SQLite were
3771 ** more tolerant of invalid F parameters than newer versions.
3773 ** If F is a suitable filename (as described in the previous paragraph)
3774 ** and if P is the name of the query parameter, then
3775 ** sqlite3_uri_parameter(F,P) returns the value of the P
3776 ** parameter if it exists or a NULL pointer if P does not appear as a
3777 ** query parameter on F. If P is a query parameter of F and it
3778 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns
3779 ** a pointer to an empty string.
3781 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
3782 ** parameter and returns true (1) or false (0) according to the value
3783 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
3784 ** value of query parameter P is one of "yes", "true", or "on" in any
3785 ** case or if the value begins with a non-zero number. The
3786 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
3787 ** query parameter P is one of "no", "false", or "off" in any case or
3788 ** if the value begins with a numeric zero. If P is not a query
3789 ** parameter on F or if the value of P does not match any of the
3790 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
3792 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
3793 ** 64-bit signed integer and returns that integer, or D if P does not
3794 ** exist. If the value of P is something other than an integer, then
3795 ** zero is returned.
3797 ** The sqlite3_uri_key(F,N) returns a pointer to the name (not
3798 ** the value) of the N-th query parameter for filename F, or a NULL
3799 ** pointer if N is less than zero or greater than the number of query
3800 ** parameters minus 1. The N value is zero-based so N should be 0 to obtain
3801 ** the name of the first query parameter, 1 for the second parameter, and
3804 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
3805 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
3806 ** is not a database file pathname pointer that the SQLite core passed
3807 ** into the xOpen VFS method, then the behavior of this routine is undefined
3808 ** and probably undesirable.
3810 ** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F
3811 ** parameter can also be the name of a rollback journal file or WAL file
3812 ** in addition to the main database file. Prior to version 3.31.0, these
3813 ** routines would only work if F was the name of the main database file.
3814 ** When the F parameter is the name of the rollback journal or WAL file,
3815 ** it has access to all the same query parameters as were found on the
3816 ** main database file.
3818 ** See the [URI filename] documentation for additional information.
3820 SQLITE_API const char *sqlite3_uri_parameter(sqlite3_filename z, const char *zParam);
3821 SQLITE_API int sqlite3_uri_boolean(sqlite3_filename z, const char *zParam, int bDefault);
3822 SQLITE_API sqlite3_int64 sqlite3_uri_int64(sqlite3_filename, const char*, sqlite3_int64);
3823 SQLITE_API const char *sqlite3_uri_key(sqlite3_filename z, int N);
3826 ** CAPI3REF: Translate filenames
3828 ** These routines are available to [VFS|custom VFS implementations] for
3829 ** translating filenames between the main database file, the journal file,
3830 ** and the WAL file.
3832 ** If F is the name of an sqlite database file, journal file, or WAL file
3833 ** passed by the SQLite core into the VFS, then sqlite3_filename_database(F)
3834 ** returns the name of the corresponding database file.
3836 ** If F is the name of an sqlite database file, journal file, or WAL file
3837 ** passed by the SQLite core into the VFS, or if F is a database filename
3838 ** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F)
3839 ** returns the name of the corresponding rollback journal file.
3841 ** If F is the name of an sqlite database file, journal file, or WAL file
3842 ** that was passed by the SQLite core into the VFS, or if F is a database
3843 ** filename obtained from [sqlite3_db_filename()], then
3844 ** sqlite3_filename_wal(F) returns the name of the corresponding
3847 ** In all of the above, if F is not the name of a database, journal or WAL
3848 ** filename passed into the VFS from the SQLite core and F is not the
3849 ** return value from [sqlite3_db_filename()], then the result is
3850 ** undefined and is likely a memory access violation.
3852 SQLITE_API const char *sqlite3_filename_database(sqlite3_filename);
3853 SQLITE_API const char *sqlite3_filename_journal(sqlite3_filename);
3854 SQLITE_API const char *sqlite3_filename_wal(sqlite3_filename);
3857 ** CAPI3REF: Database File Corresponding To A Journal
3859 ** ^If X is the name of a rollback or WAL-mode journal file that is
3860 ** passed into the xOpen method of [sqlite3_vfs], then
3861 ** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file]
3862 ** object that represents the main database file.
3864 ** This routine is intended for use in custom [VFS] implementations
3865 ** only. It is not a general-purpose interface.
3866 ** The argument sqlite3_file_object(X) must be a filename pointer that
3867 ** has been passed into [sqlite3_vfs].xOpen method where the
3868 ** flags parameter to xOpen contains one of the bits
3869 ** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use
3870 ** of this routine results in undefined and probably undesirable
3873 SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*);
3876 ** CAPI3REF: Create and Destroy VFS Filenames
3878 ** These interfaces are provided for use by [VFS shim] implementations and
3879 ** are not useful outside of that context.
3881 ** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of
3882 ** database filename D with corresponding journal file J and WAL file W and
3883 ** with N URI parameters key/values pairs in the array P. The result from
3884 ** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that
3885 ** is safe to pass to routines like:
3887 ** <li> [sqlite3_uri_parameter()],
3888 ** <li> [sqlite3_uri_boolean()],
3889 ** <li> [sqlite3_uri_int64()],
3890 ** <li> [sqlite3_uri_key()],
3891 ** <li> [sqlite3_filename_database()],
3892 ** <li> [sqlite3_filename_journal()], or
3893 ** <li> [sqlite3_filename_wal()].
3895 ** If a memory allocation error occurs, sqlite3_create_filename() might
3896 ** return a NULL pointer. The memory obtained from sqlite3_create_filename(X)
3897 ** must be released by a corresponding call to sqlite3_free_filename(Y).
3899 ** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array
3900 ** of 2*N pointers to strings. Each pair of pointers in this array corresponds
3901 ** to a key and value for a query parameter. The P parameter may be a NULL
3902 ** pointer if N is zero. None of the 2*N pointers in the P array may be
3903 ** NULL pointers and key pointers should not be empty strings.
3904 ** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may
3905 ** be NULL pointers, though they can be empty strings.
3907 ** The sqlite3_free_filename(Y) routine releases a memory allocation
3908 ** previously obtained from sqlite3_create_filename(). Invoking
3909 ** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op.
3911 ** If the Y parameter to sqlite3_free_filename(Y) is anything other
3912 ** than a NULL pointer or a pointer previously acquired from
3913 ** sqlite3_create_filename(), then bad things such as heap
3914 ** corruption or segfaults may occur. The value Y should not be
3915 ** used again after sqlite3_free_filename(Y) has been called. This means
3916 ** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y,
3917 ** then the corresponding [sqlite3_module.xClose() method should also be
3918 ** invoked prior to calling sqlite3_free_filename(Y).
3920 SQLITE_API sqlite3_filename sqlite3_create_filename(
3921 const char *zDatabase,
3922 const char *zJournal,
3925 const char **azParam
3927 SQLITE_API void sqlite3_free_filename(sqlite3_filename);
3930 ** CAPI3REF: Error Codes And Messages
3933 ** ^If the most recent sqlite3_* API call associated with
3934 ** [database connection] D failed, then the sqlite3_errcode(D) interface
3935 ** returns the numeric [result code] or [extended result code] for that
3937 ** ^The sqlite3_extended_errcode()
3938 ** interface is the same except that it always returns the
3939 ** [extended result code] even when extended result codes are
3942 ** The values returned by sqlite3_errcode() and/or
3943 ** sqlite3_extended_errcode() might change with each API call.
3944 ** Except, there are some interfaces that are guaranteed to never
3945 ** change the value of the error code. The error-code preserving
3946 ** interfaces include the following:
3949 ** <li> sqlite3_errcode()
3950 ** <li> sqlite3_extended_errcode()
3951 ** <li> sqlite3_errmsg()
3952 ** <li> sqlite3_errmsg16()
3953 ** <li> sqlite3_error_offset()
3956 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
3957 ** text that describes the error, as either UTF-8 or UTF-16 respectively,
3958 ** or NULL if no error message is available.
3959 ** (See how SQLite handles [invalid UTF] for exceptions to this rule.)
3960 ** ^(Memory to hold the error message string is managed internally.
3961 ** The application does not need to worry about freeing the result.
3962 ** However, the error string might be overwritten or deallocated by
3963 ** subsequent calls to other SQLite interface functions.)^
3965 ** ^The sqlite3_errstr(E) interface returns the English-language text
3966 ** that describes the [result code] E, as UTF-8, or NULL if E is not an
3967 ** result code for which a text error message is available.
3968 ** ^(Memory to hold the error message string is managed internally
3969 ** and must not be freed by the application)^.
3971 ** ^If the most recent error references a specific token in the input
3972 ** SQL, the sqlite3_error_offset() interface returns the byte offset
3973 ** of the start of that token. ^The byte offset returned by
3974 ** sqlite3_error_offset() assumes that the input SQL is UTF8.
3975 ** ^If the most recent error does not reference a specific token in the input
3976 ** SQL, then the sqlite3_error_offset() function returns -1.
3978 ** When the serialized [threading mode] is in use, it might be the
3979 ** case that a second error occurs on a separate thread in between
3980 ** the time of the first error and the call to these interfaces.
3981 ** When that happens, the second error will be reported since these
3982 ** interfaces always report the most recent result. To avoid
3983 ** this, each thread can obtain exclusive use of the [database connection] D
3984 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
3985 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
3986 ** all calls to the interfaces listed here are completed.
3988 ** If an interface fails with SQLITE_MISUSE, that means the interface
3989 ** was invoked incorrectly by the application. In that case, the
3990 ** error code and message may or may not be set.
3992 SQLITE_API int sqlite3_errcode(sqlite3 *db);
3993 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
3994 SQLITE_API const char *sqlite3_errmsg(sqlite3*);
3995 SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
3996 SQLITE_API const char *sqlite3_errstr(int);
3997 SQLITE_API int sqlite3_error_offset(sqlite3 *db);
4000 ** CAPI3REF: Prepared Statement Object
4001 ** KEYWORDS: {prepared statement} {prepared statements}
4003 ** An instance of this object represents a single SQL statement that
4004 ** has been compiled into binary form and is ready to be evaluated.
4006 ** Think of each SQL statement as a separate computer program. The
4007 ** original SQL text is source code. A prepared statement object
4008 ** is the compiled object code. All SQL must be converted into a
4009 ** prepared statement before it can be run.
4011 ** The life-cycle of a prepared statement object usually goes like this:
4014 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
4015 ** <li> Bind values to [parameters] using the sqlite3_bind_*()
4017 ** <li> Run the SQL by calling [sqlite3_step()] one or more times.
4018 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back
4019 ** to step 2. Do this zero or more times.
4020 ** <li> Destroy the object using [sqlite3_finalize()].
4023 typedef struct sqlite3_stmt sqlite3_stmt;
4026 ** CAPI3REF: Run-time Limits
4029 ** ^(This interface allows the size of various constructs to be limited
4030 ** on a connection by connection basis. The first parameter is the
4031 ** [database connection] whose limit is to be set or queried. The
4032 ** second parameter is one of the [limit categories] that define a
4033 ** class of constructs to be size limited. The third parameter is the
4034 ** new limit for that construct.)^
4036 ** ^If the new limit is a negative number, the limit is unchanged.
4037 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
4038 ** [limits | hard upper bound]
4039 ** set at compile-time by a C preprocessor macro called
4040 ** [limits | SQLITE_MAX_<i>NAME</i>].
4041 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^
4042 ** ^Attempts to increase a limit above its hard upper bound are
4043 ** silently truncated to the hard upper bound.
4045 ** ^Regardless of whether or not the limit was changed, the
4046 ** [sqlite3_limit()] interface returns the prior value of the limit.
4047 ** ^Hence, to find the current value of a limit without changing it,
4048 ** simply invoke this interface with the third parameter set to -1.
4050 ** Run-time limits are intended for use in applications that manage
4051 ** both their own internal database and also databases that are controlled
4052 ** by untrusted external sources. An example application might be a
4053 ** web browser that has its own databases for storing history and
4054 ** separate databases controlled by JavaScript applications downloaded
4055 ** off the Internet. The internal databases can be given the
4056 ** large, default limits. Databases managed by external sources can
4057 ** be given much smaller limits designed to prevent a denial of service
4058 ** attack. Developers might also want to use the [sqlite3_set_authorizer()]
4059 ** interface to further control untrusted SQL. The size of the database
4060 ** created by an untrusted script can be contained using the
4061 ** [max_page_count] [PRAGMA].
4063 ** New run-time limit categories may be added in future releases.
4065 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
4068 ** CAPI3REF: Run-Time Limit Categories
4069 ** KEYWORDS: {limit category} {*limit categories}
4071 ** These constants define various performance limits
4072 ** that can be lowered at run-time using [sqlite3_limit()].
4073 ** The synopsis of the meanings of the various limits is shown below.
4074 ** Additional information is available at [limits | Limits in SQLite].
4077 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
4078 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
4080 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
4081 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
4083 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
4084 ** <dd>The maximum number of columns in a table definition or in the
4085 ** result set of a [SELECT] or the maximum number of columns in an index
4086 ** or in an ORDER BY or GROUP BY clause.</dd>)^
4088 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
4089 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^
4091 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
4092 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
4094 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
4095 ** <dd>The maximum number of instructions in a virtual machine program
4096 ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or
4097 ** the equivalent tries to allocate space for more than this many opcodes
4098 ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^
4100 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
4101 ** <dd>The maximum number of arguments on a function.</dd>)^
4103 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
4104 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
4106 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
4107 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
4108 ** <dd>The maximum length of the pattern argument to the [LIKE] or
4109 ** [GLOB] operators.</dd>)^
4111 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
4112 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
4113 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^
4115 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
4116 ** <dd>The maximum depth of recursion for triggers.</dd>)^
4118 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
4119 ** <dd>The maximum number of auxiliary worker threads that a single
4120 ** [prepared statement] may start.</dd>)^
4123 #define SQLITE_LIMIT_LENGTH 0
4124 #define SQLITE_LIMIT_SQL_LENGTH 1
4125 #define SQLITE_LIMIT_COLUMN 2
4126 #define SQLITE_LIMIT_EXPR_DEPTH 3
4127 #define SQLITE_LIMIT_COMPOUND_SELECT 4
4128 #define SQLITE_LIMIT_VDBE_OP 5
4129 #define SQLITE_LIMIT_FUNCTION_ARG 6
4130 #define SQLITE_LIMIT_ATTACHED 7
4131 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
4132 #define SQLITE_LIMIT_VARIABLE_NUMBER 9
4133 #define SQLITE_LIMIT_TRIGGER_DEPTH 10
4134 #define SQLITE_LIMIT_WORKER_THREADS 11
4137 ** CAPI3REF: Prepare Flags
4139 ** These constants define various flags that can be passed into
4140 ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and
4141 ** [sqlite3_prepare16_v3()] interfaces.
4143 ** New flags may be added in future releases of SQLite.
4146 ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt>
4147 ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner
4148 ** that the prepared statement will be retained for a long time and
4149 ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()]
4150 ** and [sqlite3_prepare16_v3()] assume that the prepared statement will
4151 ** be used just once or at most a few times and then destroyed using
4152 ** [sqlite3_finalize()] relatively soon. The current implementation acts
4153 ** on this hint by avoiding the use of [lookaside memory] so as not to
4154 ** deplete the limited store of lookaside memory. Future versions of
4155 ** SQLite may act on this hint differently.
4157 ** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt>
4158 ** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used
4159 ** to be required for any prepared statement that wanted to use the
4160 ** [sqlite3_normalized_sql()] interface. However, the
4161 ** [sqlite3_normalized_sql()] interface is now available to all
4162 ** prepared statements, regardless of whether or not they use this
4165 ** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt>
4166 ** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler
4167 ** to return an error (error code SQLITE_ERROR) if the statement uses
4168 ** any virtual tables.
4171 #define SQLITE_PREPARE_PERSISTENT 0x01
4172 #define SQLITE_PREPARE_NORMALIZE 0x02
4173 #define SQLITE_PREPARE_NO_VTAB 0x04
4176 ** CAPI3REF: Compiling An SQL Statement
4177 ** KEYWORDS: {SQL statement compiler}
4179 ** CONSTRUCTOR: sqlite3_stmt
4181 ** To execute an SQL statement, it must first be compiled into a byte-code
4182 ** program using one of these routines. Or, in other words, these routines
4183 ** are constructors for the [prepared statement] object.
4185 ** The preferred routine to use is [sqlite3_prepare_v2()]. The
4186 ** [sqlite3_prepare()] interface is legacy and should be avoided.
4187 ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used
4188 ** for special purposes.
4190 ** The use of the UTF-8 interfaces is preferred, as SQLite currently
4191 ** does all parsing using UTF-8. The UTF-16 interfaces are provided
4192 ** as a convenience. The UTF-16 interfaces work by converting the
4193 ** input text into UTF-8, then invoking the corresponding UTF-8 interface.
4195 ** The first argument, "db", is a [database connection] obtained from a
4196 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
4197 ** [sqlite3_open16()]. The database connection must not have been closed.
4199 ** The second argument, "zSql", is the statement to be compiled, encoded
4200 ** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(),
4201 ** and sqlite3_prepare_v3()
4202 ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(),
4203 ** and sqlite3_prepare16_v3() use UTF-16.
4205 ** ^If the nByte argument is negative, then zSql is read up to the
4206 ** first zero terminator. ^If nByte is positive, then it is the
4207 ** number of bytes read from zSql. ^If nByte is zero, then no prepared
4208 ** statement is generated.
4209 ** If the caller knows that the supplied string is nul-terminated, then
4210 ** there is a small performance advantage to passing an nByte parameter that
4211 ** is the number of bytes in the input string <i>including</i>
4212 ** the nul-terminator.
4214 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte
4215 ** past the end of the first SQL statement in zSql. These routines only
4216 ** compile the first statement in zSql, so *pzTail is left pointing to
4217 ** what remains uncompiled.
4219 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
4220 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
4221 ** to NULL. ^If the input text contains no SQL (if the input is an empty
4222 ** string or a comment) then *ppStmt is set to NULL.
4223 ** The calling procedure is responsible for deleting the compiled
4224 ** SQL statement using [sqlite3_finalize()] after it has finished with it.
4225 ** ppStmt may not be NULL.
4227 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
4228 ** otherwise an [error code] is returned.
4230 ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(),
4231 ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs.
4232 ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16())
4233 ** are retained for backwards compatibility, but their use is discouraged.
4234 ** ^In the "vX" interfaces, the prepared statement
4235 ** that is returned (the [sqlite3_stmt] object) contains a copy of the
4236 ** original SQL text. This causes the [sqlite3_step()] interface to
4237 ** behave differently in three ways:
4241 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
4242 ** always used to do, [sqlite3_step()] will automatically recompile the SQL
4243 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
4244 ** retries will occur before sqlite3_step() gives up and returns an error.
4248 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed
4249 ** [error codes] or [extended error codes]. ^The legacy behavior was that
4250 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
4251 ** and the application would have to make a second call to [sqlite3_reset()]
4252 ** in order to find the underlying cause of the problem. With the "v2" prepare
4253 ** interfaces, the underlying reason for the error is returned immediately.
4257 ** ^If the specific value bound to a [parameter | host parameter] in the
4258 ** WHERE clause might influence the choice of query plan for a statement,
4259 ** then the statement will be automatically recompiled, as if there had been
4260 ** a schema change, on the first [sqlite3_step()] call following any change
4261 ** to the [sqlite3_bind_text | bindings] of that [parameter].
4262 ** ^The specific value of a WHERE-clause [parameter] might influence the
4263 ** choice of query plan if the parameter is the left-hand side of a [LIKE]
4264 ** or [GLOB] operator or if the parameter is compared to an indexed column
4265 ** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled.
4269 ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having
4270 ** the extra prepFlags parameter, which is a bit array consisting of zero or
4271 ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The
4272 ** sqlite3_prepare_v2() interface works exactly the same as
4273 ** sqlite3_prepare_v3() with a zero prepFlags parameter.
4275 SQLITE_API int sqlite3_prepare(
4276 sqlite3 *db, /* Database handle */
4277 const char *zSql, /* SQL statement, UTF-8 encoded */
4278 int nByte, /* Maximum length of zSql in bytes. */
4279 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4280 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4282 SQLITE_API int sqlite3_prepare_v2(
4283 sqlite3 *db, /* Database handle */
4284 const char *zSql, /* SQL statement, UTF-8 encoded */
4285 int nByte, /* Maximum length of zSql in bytes. */
4286 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4287 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4289 SQLITE_API int sqlite3_prepare_v3(
4290 sqlite3 *db, /* Database handle */
4291 const char *zSql, /* SQL statement, UTF-8 encoded */
4292 int nByte, /* Maximum length of zSql in bytes. */
4293 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4294 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4295 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4297 SQLITE_API int sqlite3_prepare16(
4298 sqlite3 *db, /* Database handle */
4299 const void *zSql, /* SQL statement, UTF-16 encoded */
4300 int nByte, /* Maximum length of zSql in bytes. */
4301 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4302 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4304 SQLITE_API int sqlite3_prepare16_v2(
4305 sqlite3 *db, /* Database handle */
4306 const void *zSql, /* SQL statement, UTF-16 encoded */
4307 int nByte, /* Maximum length of zSql in bytes. */
4308 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4309 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4311 SQLITE_API int sqlite3_prepare16_v3(
4312 sqlite3 *db, /* Database handle */
4313 const void *zSql, /* SQL statement, UTF-16 encoded */
4314 int nByte, /* Maximum length of zSql in bytes. */
4315 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4316 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4317 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4321 ** CAPI3REF: Retrieving Statement SQL
4322 ** METHOD: sqlite3_stmt
4324 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8
4325 ** SQL text used to create [prepared statement] P if P was
4326 ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()],
4327 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4328 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8
4329 ** string containing the SQL text of prepared statement P with
4330 ** [bound parameters] expanded.
4331 ** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8
4332 ** string containing the normalized SQL text of prepared statement P. The
4333 ** semantics used to normalize a SQL statement are unspecified and subject
4334 ** to change. At a minimum, literal values will be replaced with suitable
4337 ** ^(For example, if a prepared statement is created using the SQL
4338 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
4339 ** and parameter :xyz is unbound, then sqlite3_sql() will return
4340 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
4341 ** will return "SELECT 2345,NULL".)^
4343 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
4344 ** is available to hold the result, or if the result would exceed the
4345 ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH].
4347 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
4348 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time
4349 ** option causes sqlite3_expanded_sql() to always return NULL.
4351 ** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P)
4352 ** are managed by SQLite and are automatically freed when the prepared
4353 ** statement is finalized.
4354 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand,
4355 ** is obtained from [sqlite3_malloc()] and must be freed by the application
4356 ** by passing it to [sqlite3_free()].
4358 ** ^The sqlite3_normalized_sql() interface is only available if
4359 ** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined.
4361 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
4362 SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt);
4363 #ifdef SQLITE_ENABLE_NORMALIZE
4364 SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt);
4368 ** CAPI3REF: Determine If An SQL Statement Writes The Database
4369 ** METHOD: sqlite3_stmt
4371 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
4372 ** and only if the [prepared statement] X makes no direct changes to
4373 ** the content of the database file.
4375 ** Note that [application-defined SQL functions] or
4376 ** [virtual tables] might change the database indirectly as a side effect.
4377 ** ^(For example, if an application defines a function "eval()" that
4378 ** calls [sqlite3_exec()], then the following SQL statement would
4379 ** change the database file through side-effects:
4381 ** <blockquote><pre>
4382 ** SELECT eval('DELETE FROM t1') FROM t2;
4383 ** </pre></blockquote>
4385 ** But because the [SELECT] statement does not change the database file
4386 ** directly, sqlite3_stmt_readonly() would still return true.)^
4388 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
4389 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
4390 ** since the statements themselves do not actually modify the database but
4391 ** rather they control the timing of when other statements modify the
4392 ** database. ^The [ATTACH] and [DETACH] statements also cause
4393 ** sqlite3_stmt_readonly() to return true since, while those statements
4394 ** change the configuration of a database connection, they do not make
4395 ** changes to the content of the database files on disk.
4396 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since
4397 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and
4398 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so
4399 ** sqlite3_stmt_readonly() returns false for those commands.
4401 ** ^This routine returns false if there is any possibility that the
4402 ** statement might change the database file. ^A false return does
4403 ** not guarantee that the statement will change the database file.
4404 ** ^For example, an UPDATE statement might have a WHERE clause that
4405 ** makes it a no-op, but the sqlite3_stmt_readonly() result would still
4406 ** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a
4407 ** read-only no-op if the table already exists, but
4408 ** sqlite3_stmt_readonly() still returns false for such a statement.
4410 ** ^If prepared statement X is an [EXPLAIN] or [EXPLAIN QUERY PLAN]
4411 ** statement, then sqlite3_stmt_readonly(X) returns the same value as
4412 ** if the EXPLAIN or EXPLAIN QUERY PLAN prefix were omitted.
4414 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
4417 ** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement
4418 ** METHOD: sqlite3_stmt
4420 ** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the
4421 ** prepared statement S is an EXPLAIN statement, or 2 if the
4422 ** statement S is an EXPLAIN QUERY PLAN.
4423 ** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is
4424 ** an ordinary statement or a NULL pointer.
4426 SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt);
4429 ** CAPI3REF: Change The EXPLAIN Setting For A Prepared Statement
4430 ** METHOD: sqlite3_stmt
4432 ** The sqlite3_stmt_explain(S,E) interface changes the EXPLAIN
4433 ** setting for [prepared statement] S. If E is zero, then S becomes
4434 ** a normal prepared statement. If E is 1, then S behaves as if
4435 ** its SQL text began with "[EXPLAIN]". If E is 2, then S behaves as if
4436 ** its SQL text began with "[EXPLAIN QUERY PLAN]".
4438 ** Calling sqlite3_stmt_explain(S,E) might cause S to be reprepared.
4439 ** SQLite tries to avoid a reprepare, but a reprepare might be necessary
4440 ** on the first transition into EXPLAIN or EXPLAIN QUERY PLAN mode.
4442 ** Because of the potential need to reprepare, a call to
4443 ** sqlite3_stmt_explain(S,E) will fail with SQLITE_ERROR if S cannot be
4444 ** reprepared because it was created using [sqlite3_prepare()] instead of
4445 ** the newer [sqlite3_prepare_v2()] or [sqlite3_prepare_v3()] interfaces and
4446 ** hence has no saved SQL text with which to reprepare.
4448 ** Changing the explain setting for a prepared statement does not change
4449 ** the original SQL text for the statement. Hence, if the SQL text originally
4450 ** began with EXPLAIN or EXPLAIN QUERY PLAN, but sqlite3_stmt_explain(S,0)
4451 ** is called to convert the statement into an ordinary statement, the EXPLAIN
4452 ** or EXPLAIN QUERY PLAN keywords will still appear in the sqlite3_sql(S)
4453 ** output, even though the statement now acts like a normal SQL statement.
4455 ** This routine returns SQLITE_OK if the explain mode is successfully
4456 ** changed, or an error code if the explain mode could not be changed.
4457 ** The explain mode cannot be changed while a statement is active.
4458 ** Hence, it is good practice to call [sqlite3_reset(S)]
4459 ** immediately prior to calling sqlite3_stmt_explain(S,E).
4461 SQLITE_API int sqlite3_stmt_explain(sqlite3_stmt *pStmt, int eMode);
4464 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset
4465 ** METHOD: sqlite3_stmt
4467 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
4468 ** [prepared statement] S has been stepped at least once using
4469 ** [sqlite3_step(S)] but has neither run to completion (returned
4470 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor
4471 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
4472 ** interface returns false if S is a NULL pointer. If S is not a
4473 ** NULL pointer and is not a pointer to a valid [prepared statement]
4474 ** object, then the behavior is undefined and probably undesirable.
4476 ** This interface can be used in combination [sqlite3_next_stmt()]
4477 ** to locate all prepared statements associated with a database
4478 ** connection that are in need of being reset. This can be used,
4479 ** for example, in diagnostic routines to search for prepared
4480 ** statements that are holding a transaction open.
4482 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
4485 ** CAPI3REF: Dynamically Typed Value Object
4486 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
4488 ** SQLite uses the sqlite3_value object to represent all values
4489 ** that can be stored in a database table. SQLite uses dynamic typing
4490 ** for the values it stores. ^Values stored in sqlite3_value objects
4491 ** can be integers, floating point values, strings, BLOBs, or NULL.
4493 ** An sqlite3_value object may be either "protected" or "unprotected".
4494 ** Some interfaces require a protected sqlite3_value. Other interfaces
4495 ** will accept either a protected or an unprotected sqlite3_value.
4496 ** Every interface that accepts sqlite3_value arguments specifies
4497 ** whether or not it requires a protected sqlite3_value. The
4498 ** [sqlite3_value_dup()] interface can be used to construct a new
4499 ** protected sqlite3_value from an unprotected sqlite3_value.
4501 ** The terms "protected" and "unprotected" refer to whether or not
4502 ** a mutex is held. An internal mutex is held for a protected
4503 ** sqlite3_value object but no mutex is held for an unprotected
4504 ** sqlite3_value object. If SQLite is compiled to be single-threaded
4505 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
4506 ** or if SQLite is run in one of reduced mutex modes
4507 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
4508 ** then there is no distinction between protected and unprotected
4509 ** sqlite3_value objects and they can be used interchangeably. However,
4510 ** for maximum code portability it is recommended that applications
4511 ** still make the distinction between protected and unprotected
4512 ** sqlite3_value objects even when not strictly required.
4514 ** ^The sqlite3_value objects that are passed as parameters into the
4515 ** implementation of [application-defined SQL functions] are protected.
4516 ** ^The sqlite3_value objects returned by [sqlite3_vtab_rhs_value()]
4518 ** ^The sqlite3_value object returned by
4519 ** [sqlite3_column_value()] is unprotected.
4520 ** Unprotected sqlite3_value objects may only be used as arguments
4521 ** to [sqlite3_result_value()], [sqlite3_bind_value()], and
4522 ** [sqlite3_value_dup()].
4523 ** The [sqlite3_value_blob | sqlite3_value_type()] family of
4524 ** interfaces require protected sqlite3_value objects.
4526 typedef struct sqlite3_value sqlite3_value;
4529 ** CAPI3REF: SQL Function Context Object
4531 ** The context in which an SQL function executes is stored in an
4532 ** sqlite3_context object. ^A pointer to an sqlite3_context object
4533 ** is always first parameter to [application-defined SQL functions].
4534 ** The application-defined SQL function implementation will pass this
4535 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
4536 ** [sqlite3_aggregate_context()], [sqlite3_user_data()],
4537 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
4538 ** and/or [sqlite3_set_auxdata()].
4540 typedef struct sqlite3_context sqlite3_context;
4543 ** CAPI3REF: Binding Values To Prepared Statements
4544 ** KEYWORDS: {host parameter} {host parameters} {host parameter name}
4545 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
4546 ** METHOD: sqlite3_stmt
4548 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
4549 ** literals may be replaced by a [parameter] that matches one of following
4560 ** In the templates above, NNN represents an integer literal,
4561 ** and VVV represents an alphanumeric identifier.)^ ^The values of these
4562 ** parameters (also called "host parameter names" or "SQL parameters")
4563 ** can be set using the sqlite3_bind_*() routines defined here.
4565 ** ^The first argument to the sqlite3_bind_*() routines is always
4566 ** a pointer to the [sqlite3_stmt] object returned from
4567 ** [sqlite3_prepare_v2()] or its variants.
4569 ** ^The second argument is the index of the SQL parameter to be set.
4570 ** ^The leftmost SQL parameter has an index of 1. ^When the same named
4571 ** SQL parameter is used more than once, second and subsequent
4572 ** occurrences have the same index as the first occurrence.
4573 ** ^The index for named parameters can be looked up using the
4574 ** [sqlite3_bind_parameter_index()] API if desired. ^The index
4575 ** for "?NNN" parameters is the value of NNN.
4576 ** ^The NNN value must be between 1 and the [sqlite3_limit()]
4577 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766).
4579 ** ^The third argument is the value to bind to the parameter.
4580 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4581 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
4582 ** is ignored and the end result is the same as sqlite3_bind_null().
4583 ** ^If the third parameter to sqlite3_bind_text() is not NULL, then
4584 ** it should be a pointer to well-formed UTF8 text.
4585 ** ^If the third parameter to sqlite3_bind_text16() is not NULL, then
4586 ** it should be a pointer to well-formed UTF16 text.
4587 ** ^If the third parameter to sqlite3_bind_text64() is not NULL, then
4588 ** it should be a pointer to a well-formed unicode string that is
4589 ** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16
4592 ** [[byte-order determination rules]] ^The byte-order of
4593 ** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF)
4594 ** found in first character, which is removed, or in the absence of a BOM
4595 ** the byte order is the native byte order of the host
4596 ** machine for sqlite3_bind_text16() or the byte order specified in
4597 ** the 6th parameter for sqlite3_bind_text64().)^
4598 ** ^If UTF16 input text contains invalid unicode
4599 ** characters, then SQLite might change those invalid characters
4600 ** into the unicode replacement character: U+FFFD.
4602 ** ^(In those routines that have a fourth argument, its value is the
4603 ** number of bytes in the parameter. To be clear: the value is the
4604 ** number of <u>bytes</u> in the value, not the number of characters.)^
4605 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4606 ** is negative, then the length of the string is
4607 ** the number of bytes up to the first zero terminator.
4608 ** If the fourth parameter to sqlite3_bind_blob() is negative, then
4609 ** the behavior is undefined.
4610 ** If a non-negative fourth parameter is provided to sqlite3_bind_text()
4611 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then
4612 ** that parameter must be the byte offset
4613 ** where the NUL terminator would occur assuming the string were NUL
4614 ** terminated. If any NUL characters occurs at byte offsets less than
4615 ** the value of the fourth parameter then the resulting string value will
4616 ** contain embedded NULs. The result of expressions involving strings
4617 ** with embedded NULs is undefined.
4619 ** ^The fifth argument to the BLOB and string binding interfaces controls
4620 ** or indicates the lifetime of the object referenced by the third parameter.
4621 ** These three options exist:
4622 ** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished
4623 ** with it may be passed. ^It is called to dispose of the BLOB or string even
4624 ** if the call to the bind API fails, except the destructor is not called if
4625 ** the third parameter is a NULL pointer or the fourth parameter is negative.
4626 ** ^ (2) The special constant, [SQLITE_STATIC], may be passed to indicate that
4627 ** the application remains responsible for disposing of the object. ^In this
4628 ** case, the object and the provided pointer to it must remain valid until
4629 ** either the prepared statement is finalized or the same SQL parameter is
4630 ** bound to something else, whichever occurs sooner.
4631 ** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the
4632 ** object is to be copied prior to the return from sqlite3_bind_*(). ^The
4633 ** object and pointer to it must remain valid until then. ^SQLite will then
4634 ** manage the lifetime of its private copy.
4636 ** ^The sixth argument to sqlite3_bind_text64() must be one of
4637 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]
4638 ** to specify the encoding of the text in the third parameter. If
4639 ** the sixth argument to sqlite3_bind_text64() is not one of the
4640 ** allowed values shown above, or if the text encoding is different
4641 ** from the encoding specified by the sixth parameter, then the behavior
4644 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
4645 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
4646 ** (just an integer to hold its size) while it is being processed.
4647 ** Zeroblobs are intended to serve as placeholders for BLOBs whose
4648 ** content is later written using
4649 ** [sqlite3_blob_open | incremental BLOB I/O] routines.
4650 ** ^A negative value for the zeroblob results in a zero-length BLOB.
4652 ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in
4653 ** [prepared statement] S to have an SQL value of NULL, but to also be
4654 ** associated with the pointer P of type T. ^D is either a NULL pointer or
4655 ** a pointer to a destructor function for P. ^SQLite will invoke the
4656 ** destructor D with a single argument of P when it is finished using
4657 ** P. The T parameter should be a static string, preferably a string
4658 ** literal. The sqlite3_bind_pointer() routine is part of the
4659 ** [pointer passing interface] added for SQLite 3.20.0.
4661 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
4662 ** for the [prepared statement] or with a prepared statement for which
4663 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
4664 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
4665 ** routine is passed a [prepared statement] that has been finalized, the
4666 ** result is undefined and probably harmful.
4668 ** ^Bindings are not cleared by the [sqlite3_reset()] routine.
4669 ** ^Unbound parameters are interpreted as NULL.
4671 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
4672 ** [error code] if anything goes wrong.
4673 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
4674 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
4675 ** [SQLITE_MAX_LENGTH].
4676 ** ^[SQLITE_RANGE] is returned if the parameter
4677 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
4679 ** See also: [sqlite3_bind_parameter_count()],
4680 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
4682 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
4683 SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
4685 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
4686 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
4687 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
4688 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
4689 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
4690 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
4691 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
4692 void(*)(void*), unsigned char encoding);
4693 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
4694 SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*));
4695 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
4696 SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
4699 ** CAPI3REF: Number Of SQL Parameters
4700 ** METHOD: sqlite3_stmt
4702 ** ^This routine can be used to find the number of [SQL parameters]
4703 ** in a [prepared statement]. SQL parameters are tokens of the
4704 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
4705 ** placeholders for values that are [sqlite3_bind_blob | bound]
4706 ** to the parameters at a later time.
4708 ** ^(This routine actually returns the index of the largest (rightmost)
4709 ** parameter. For all forms except ?NNN, this will correspond to the
4710 ** number of unique parameters. If parameters of the ?NNN form are used,
4711 ** there may be gaps in the list.)^
4713 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
4714 ** [sqlite3_bind_parameter_name()], and
4715 ** [sqlite3_bind_parameter_index()].
4717 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
4720 ** CAPI3REF: Name Of A Host Parameter
4721 ** METHOD: sqlite3_stmt
4723 ** ^The sqlite3_bind_parameter_name(P,N) interface returns
4724 ** the name of the N-th [SQL parameter] in the [prepared statement] P.
4725 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
4726 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
4728 ** In other words, the initial ":" or "$" or "@" or "?"
4729 ** is included as part of the name.)^
4730 ** ^Parameters of the form "?" without a following integer have no name
4731 ** and are referred to as "nameless" or "anonymous parameters".
4733 ** ^The first host parameter has an index of 1, not 0.
4735 ** ^If the value N is out of range or if the N-th parameter is
4736 ** nameless, then NULL is returned. ^The returned string is
4737 ** always in UTF-8 encoding even if the named parameter was
4738 ** originally specified as UTF-16 in [sqlite3_prepare16()],
4739 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4741 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
4742 ** [sqlite3_bind_parameter_count()], and
4743 ** [sqlite3_bind_parameter_index()].
4745 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
4748 ** CAPI3REF: Index Of A Parameter With A Given Name
4749 ** METHOD: sqlite3_stmt
4751 ** ^Return the index of an SQL parameter given its name. ^The
4752 ** index value returned is suitable for use as the second
4753 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
4754 ** is returned if no matching parameter is found. ^The parameter
4755 ** name must be given in UTF-8 even if the original statement
4756 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or
4757 ** [sqlite3_prepare16_v3()].
4759 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
4760 ** [sqlite3_bind_parameter_count()], and
4761 ** [sqlite3_bind_parameter_name()].
4763 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
4766 ** CAPI3REF: Reset All Bindings On A Prepared Statement
4767 ** METHOD: sqlite3_stmt
4769 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
4770 ** the [sqlite3_bind_blob | bindings] on a [prepared statement].
4771 ** ^Use this routine to reset all host parameters to NULL.
4773 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
4776 ** CAPI3REF: Number Of Columns In A Result Set
4777 ** METHOD: sqlite3_stmt
4779 ** ^Return the number of columns in the result set returned by the
4780 ** [prepared statement]. ^If this routine returns 0, that means the
4781 ** [prepared statement] returns no data (for example an [UPDATE]).
4782 ** ^However, just because this routine returns a positive number does not
4783 ** mean that one or more rows of data will be returned. ^A SELECT statement
4784 ** will always have a positive sqlite3_column_count() but depending on the
4785 ** WHERE clause constraints and the table content, it might return no rows.
4787 ** See also: [sqlite3_data_count()]
4789 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
4792 ** CAPI3REF: Column Names In A Result Set
4793 ** METHOD: sqlite3_stmt
4795 ** ^These routines return the name assigned to a particular column
4796 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
4797 ** interface returns a pointer to a zero-terminated UTF-8 string
4798 ** and sqlite3_column_name16() returns a pointer to a zero-terminated
4799 ** UTF-16 string. ^The first parameter is the [prepared statement]
4800 ** that implements the [SELECT] statement. ^The second parameter is the
4801 ** column number. ^The leftmost column is number 0.
4803 ** ^The returned string pointer is valid until either the [prepared statement]
4804 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically
4805 ** reprepared by the first call to [sqlite3_step()] for a particular run
4806 ** or until the next call to
4807 ** sqlite3_column_name() or sqlite3_column_name16() on the same column.
4809 ** ^If sqlite3_malloc() fails during the processing of either routine
4810 ** (for example during a conversion from UTF-8 to UTF-16) then a
4811 ** NULL pointer is returned.
4813 ** ^The name of a result column is the value of the "AS" clause for
4814 ** that column, if there is an AS clause. If there is no AS clause
4815 ** then the name of the column is unspecified and may change from
4816 ** one release of SQLite to the next.
4818 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
4819 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
4822 ** CAPI3REF: Source Of Data In A Query Result
4823 ** METHOD: sqlite3_stmt
4825 ** ^These routines provide a means to determine the database, table, and
4826 ** table column that is the origin of a particular result column in
4827 ** [SELECT] statement.
4828 ** ^The name of the database or table or column can be returned as
4829 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return
4830 ** the database name, the _table_ routines return the table name, and
4831 ** the origin_ routines return the column name.
4832 ** ^The returned string is valid until the [prepared statement] is destroyed
4833 ** using [sqlite3_finalize()] or until the statement is automatically
4834 ** reprepared by the first call to [sqlite3_step()] for a particular run
4835 ** or until the same information is requested
4836 ** again in a different encoding.
4838 ** ^The names returned are the original un-aliased names of the
4839 ** database, table, and column.
4841 ** ^The first argument to these interfaces is a [prepared statement].
4842 ** ^These functions return information about the Nth result column returned by
4843 ** the statement, where N is the second function argument.
4844 ** ^The left-most column is column 0 for these routines.
4846 ** ^If the Nth column returned by the statement is an expression or
4847 ** subquery and is not a column value, then all of these functions return
4848 ** NULL. ^These routines might also return NULL if a memory allocation error
4849 ** occurs. ^Otherwise, they return the name of the attached database, table,
4850 ** or column that query result column was extracted from.
4852 ** ^As with all other SQLite APIs, those whose names end with "16" return
4853 ** UTF-16 encoded strings and the other functions return UTF-8.
4855 ** ^These APIs are only available if the library was compiled with the
4856 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
4858 ** If two or more threads call one or more
4859 ** [sqlite3_column_database_name | column metadata interfaces]
4860 ** for the same [prepared statement] and result column
4861 ** at the same time then the results are undefined.
4863 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
4864 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
4865 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
4866 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
4867 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
4868 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
4871 ** CAPI3REF: Declared Datatype Of A Query Result
4872 ** METHOD: sqlite3_stmt
4874 ** ^(The first parameter is a [prepared statement].
4875 ** If this statement is a [SELECT] statement and the Nth column of the
4876 ** returned result set of that [SELECT] is a table column (not an
4877 ** expression or subquery) then the declared type of the table
4878 ** column is returned.)^ ^If the Nth column of the result set is an
4879 ** expression or subquery, then a NULL pointer is returned.
4880 ** ^The returned string is always UTF-8 encoded.
4882 ** ^(For example, given the database schema:
4884 ** CREATE TABLE t1(c1 VARIANT);
4886 ** and the following statement to be compiled:
4888 ** SELECT c1 + 1, c1 FROM t1;
4890 ** this routine would return the string "VARIANT" for the second result
4891 ** column (i==1), and a NULL pointer for the first result column (i==0).)^
4893 ** ^SQLite uses dynamic run-time typing. ^So just because a column
4894 ** is declared to contain a particular type does not mean that the
4895 ** data stored in that column is of the declared type. SQLite is
4896 ** strongly typed, but the typing is dynamic not static. ^Type
4897 ** is associated with individual values, not with the containers
4898 ** used to hold those values.
4900 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
4901 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
4904 ** CAPI3REF: Evaluate An SQL Statement
4905 ** METHOD: sqlite3_stmt
4907 ** After a [prepared statement] has been prepared using any of
4908 ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()],
4909 ** or [sqlite3_prepare16_v3()] or one of the legacy
4910 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
4911 ** must be called one or more times to evaluate the statement.
4913 ** The details of the behavior of the sqlite3_step() interface depend
4914 ** on whether the statement was prepared using the newer "vX" interfaces
4915 ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()],
4916 ** [sqlite3_prepare16_v2()] or the older legacy
4917 ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
4918 ** new "vX" interface is recommended for new applications but the legacy
4919 ** interface will continue to be supported.
4921 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
4922 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
4923 ** ^With the "v2" interface, any of the other [result codes] or
4924 ** [extended result codes] might be returned as well.
4926 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
4927 ** database locks it needs to do its job. ^If the statement is a [COMMIT]
4928 ** or occurs outside of an explicit transaction, then you can retry the
4929 ** statement. If the statement is not a [COMMIT] and occurs within an
4930 ** explicit transaction then you should rollback the transaction before
4933 ** ^[SQLITE_DONE] means that the statement has finished executing
4934 ** successfully. sqlite3_step() should not be called again on this virtual
4935 ** machine without first calling [sqlite3_reset()] to reset the virtual
4936 ** machine back to its initial state.
4938 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
4939 ** is returned each time a new row of data is ready for processing by the
4940 ** caller. The values may be accessed using the [column access functions].
4941 ** sqlite3_step() is called again to retrieve the next row of data.
4943 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
4944 ** violation) has occurred. sqlite3_step() should not be called again on
4945 ** the VM. More information may be found by calling [sqlite3_errmsg()].
4946 ** ^With the legacy interface, a more specific error code (for example,
4947 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
4948 ** can be obtained by calling [sqlite3_reset()] on the
4949 ** [prepared statement]. ^In the "v2" interface,
4950 ** the more specific error code is returned directly by sqlite3_step().
4952 ** [SQLITE_MISUSE] means that the this routine was called inappropriately.
4953 ** Perhaps it was called on a [prepared statement] that has
4954 ** already been [sqlite3_finalize | finalized] or on one that had
4955 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
4956 ** be the case that the same database connection is being used by two or
4957 ** more threads at the same moment in time.
4959 ** For all versions of SQLite up to and including 3.6.23.1, a call to
4960 ** [sqlite3_reset()] was required after sqlite3_step() returned anything
4961 ** other than [SQLITE_ROW] before any subsequent invocation of
4962 ** sqlite3_step(). Failure to reset the prepared statement using
4963 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
4964 ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1],
4965 ** sqlite3_step() began
4966 ** calling [sqlite3_reset()] automatically in this circumstance rather
4967 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility
4968 ** break because any application that ever receives an SQLITE_MISUSE error
4969 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
4970 ** can be used to restore the legacy behavior.
4972 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
4973 ** API always returns a generic error code, [SQLITE_ERROR], following any
4974 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
4975 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
4976 ** specific [error codes] that better describes the error.
4977 ** We admit that this is a goofy design. The problem has been fixed
4978 ** with the "v2" interface. If you prepare all of your SQL statements
4979 ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()]
4980 ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead
4981 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
4982 ** then the more specific [error codes] are returned directly
4983 ** by sqlite3_step(). The use of the "vX" interfaces is recommended.
4985 SQLITE_API int sqlite3_step(sqlite3_stmt*);
4988 ** CAPI3REF: Number of columns in a result set
4989 ** METHOD: sqlite3_stmt
4991 ** ^The sqlite3_data_count(P) interface returns the number of columns in the
4992 ** current row of the result set of [prepared statement] P.
4993 ** ^If prepared statement P does not have results ready to return
4994 ** (via calls to the [sqlite3_column_int | sqlite3_column()] family of
4995 ** interfaces) then sqlite3_data_count(P) returns 0.
4996 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
4997 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
4998 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
4999 ** will return non-zero if previous call to [sqlite3_step](P) returned
5000 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
5001 ** where it always returns zero since each step of that multi-step
5002 ** pragma returns 0 columns of data.
5004 ** See also: [sqlite3_column_count()]
5006 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
5009 ** CAPI3REF: Fundamental Datatypes
5010 ** KEYWORDS: SQLITE_TEXT
5012 ** ^(Every value in SQLite has one of five fundamental datatypes:
5015 ** <li> 64-bit signed integer
5016 ** <li> 64-bit IEEE floating point number
5022 ** These constants are codes for each of those types.
5024 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2
5025 ** for a completely different meaning. Software that links against both
5026 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
5029 #define SQLITE_INTEGER 1
5030 #define SQLITE_FLOAT 2
5031 #define SQLITE_BLOB 4
5032 #define SQLITE_NULL 5
5036 # define SQLITE_TEXT 3
5038 #define SQLITE3_TEXT 3
5041 ** CAPI3REF: Result Values From A Query
5042 ** KEYWORDS: {column access functions}
5043 ** METHOD: sqlite3_stmt
5046 ** <blockquote><table border=0 cellpadding=0 cellspacing=0>
5047 ** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result
5048 ** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result
5049 ** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result
5050 ** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result
5051 ** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result
5052 ** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result
5053 ** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an
5054 ** [sqlite3_value|unprotected sqlite3_value] object.
5055 ** <tr><td> <td> <td>
5056 ** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB
5057 ** or a UTF-8 TEXT result in bytes
5058 ** <tr><td><b>sqlite3_column_bytes16 </b>
5059 ** <td>→ <td>Size of UTF-16
5061 ** <tr><td><b>sqlite3_column_type</b><td>→<td>Default
5062 ** datatype of the result
5063 ** </table></blockquote>
5067 ** ^These routines return information about a single column of the current
5068 ** result row of a query. ^In every case the first argument is a pointer
5069 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
5070 ** that was returned from [sqlite3_prepare_v2()] or one of its variants)
5071 ** and the second argument is the index of the column for which information
5072 ** should be returned. ^The leftmost column of the result set has the index 0.
5073 ** ^The number of columns in the result can be determined using
5074 ** [sqlite3_column_count()].
5076 ** If the SQL statement does not currently point to a valid row, or if the
5077 ** column index is out of range, the result is undefined.
5078 ** These routines may only be called when the most recent call to
5079 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither
5080 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
5081 ** If any of these routines are called after [sqlite3_reset()] or
5082 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned
5083 ** something other than [SQLITE_ROW], the results are undefined.
5084 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
5085 ** are called from a different thread while any of these routines
5086 ** are pending, then the results are undefined.
5088 ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16)
5089 ** each return the value of a result column in a specific data format. If
5090 ** the result column is not initially in the requested format (for example,
5091 ** if the query returns an integer but the sqlite3_column_text() interface
5092 ** is used to extract the value) then an automatic type conversion is performed.
5094 ** ^The sqlite3_column_type() routine returns the
5095 ** [SQLITE_INTEGER | datatype code] for the initial data type
5096 ** of the result column. ^The returned value is one of [SQLITE_INTEGER],
5097 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].
5098 ** The return value of sqlite3_column_type() can be used to decide which
5099 ** of the first six interface should be used to extract the column value.
5100 ** The value returned by sqlite3_column_type() is only meaningful if no
5101 ** automatic type conversions have occurred for the value in question.
5102 ** After a type conversion, the result of calling sqlite3_column_type()
5103 ** is undefined, though harmless. Future
5104 ** versions of SQLite may change the behavior of sqlite3_column_type()
5105 ** following a type conversion.
5107 ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes()
5108 ** or sqlite3_column_bytes16() interfaces can be used to determine the size
5109 ** of that BLOB or string.
5111 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
5112 ** routine returns the number of bytes in that BLOB or string.
5113 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
5114 ** the string to UTF-8 and then returns the number of bytes.
5115 ** ^If the result is a numeric value then sqlite3_column_bytes() uses
5116 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
5117 ** the number of bytes in that string.
5118 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
5120 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
5121 ** routine returns the number of bytes in that BLOB or string.
5122 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
5123 ** the string to UTF-16 and then returns the number of bytes.
5124 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses
5125 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
5126 ** the number of bytes in that string.
5127 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
5129 ** ^The values returned by [sqlite3_column_bytes()] and
5130 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end
5131 ** of the string. ^For clarity: the values returned by
5132 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
5133 ** bytes in the string, not the number of characters.
5135 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
5136 ** even empty strings, are always zero-terminated. ^The return
5137 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
5139 ** ^Strings returned by sqlite3_column_text16() always have the endianness
5140 ** which is native to the platform, regardless of the text encoding set
5141 ** for the database.
5143 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
5144 ** [unprotected sqlite3_value] object. In a multithreaded environment,
5145 ** an unprotected sqlite3_value object may only be used safely with
5146 ** [sqlite3_bind_value()] and [sqlite3_result_value()].
5147 ** If the [unprotected sqlite3_value] object returned by
5148 ** [sqlite3_column_value()] is used in any other way, including calls
5149 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
5150 ** or [sqlite3_value_bytes()], the behavior is not threadsafe.
5151 ** Hence, the sqlite3_column_value() interface
5152 ** is normally only useful within the implementation of
5153 ** [application-defined SQL functions] or [virtual tables], not within
5154 ** top-level application code.
5156 ** These routines may attempt to convert the datatype of the result.
5157 ** ^For example, if the internal representation is FLOAT and a text result
5158 ** is requested, [sqlite3_snprintf()] is used internally to perform the
5159 ** conversion automatically. ^(The following table details the conversions
5160 ** that are applied:
5163 ** <table border="1">
5164 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
5166 ** <tr><td> NULL <td> INTEGER <td> Result is 0
5167 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0
5168 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer
5169 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer
5170 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
5171 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
5172 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
5173 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER
5174 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
5175 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB
5176 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER
5177 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL
5178 ** <tr><td> TEXT <td> BLOB <td> No change
5179 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER
5180 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL
5181 ** <tr><td> BLOB <td> TEXT <td> [CAST] to TEXT, ensure zero terminator
5185 ** Note that when type conversions occur, pointers returned by prior
5186 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
5187 ** sqlite3_column_text16() may be invalidated.
5188 ** Type conversions and pointer invalidations might occur
5189 ** in the following cases:
5192 ** <li> The initial content is a BLOB and sqlite3_column_text() or
5193 ** sqlite3_column_text16() is called. A zero-terminator might
5194 ** need to be added to the string.</li>
5195 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
5196 ** sqlite3_column_text16() is called. The content must be converted
5198 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
5199 ** sqlite3_column_text() is called. The content must be converted
5203 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do
5204 ** not invalidate a prior pointer, though of course the content of the buffer
5205 ** that the prior pointer references will have been modified. Other kinds
5206 ** of conversion are done in place when it is possible, but sometimes they
5207 ** are not possible and in those cases prior pointers are invalidated.
5209 ** The safest policy is to invoke these routines
5210 ** in one of the following ways:
5213 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
5214 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
5215 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
5218 ** In other words, you should call sqlite3_column_text(),
5219 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
5220 ** into the desired format, then invoke sqlite3_column_bytes() or
5221 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
5222 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to
5223 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
5224 ** with calls to sqlite3_column_bytes().
5226 ** ^The pointers returned are valid until a type conversion occurs as
5227 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
5228 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings
5229 ** and BLOBs is freed automatically. Do not pass the pointers returned
5230 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
5231 ** [sqlite3_free()].
5233 ** As long as the input parameters are correct, these routines will only
5234 ** fail if an out-of-memory error occurs during a format conversion.
5235 ** Only the following subset of interfaces are subject to out-of-memory
5239 ** <li> sqlite3_column_blob()
5240 ** <li> sqlite3_column_text()
5241 ** <li> sqlite3_column_text16()
5242 ** <li> sqlite3_column_bytes()
5243 ** <li> sqlite3_column_bytes16()
5246 ** If an out-of-memory error occurs, then the return value from these
5247 ** routines is the same as if the column had contained an SQL NULL value.
5248 ** Valid SQL NULL returns can be distinguished from out-of-memory errors
5249 ** by invoking the [sqlite3_errcode()] immediately after the suspect
5250 ** return value is obtained and before any
5251 ** other SQLite interface is called on the same [database connection].
5253 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
5254 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
5255 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
5256 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
5257 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
5258 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
5259 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
5260 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
5261 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
5262 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
5265 ** CAPI3REF: Destroy A Prepared Statement Object
5266 ** DESTRUCTOR: sqlite3_stmt
5268 ** ^The sqlite3_finalize() function is called to delete a [prepared statement].
5269 ** ^If the most recent evaluation of the statement encountered no errors
5270 ** or if the statement is never been evaluated, then sqlite3_finalize() returns
5271 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
5272 ** sqlite3_finalize(S) returns the appropriate [error code] or
5273 ** [extended error code].
5275 ** ^The sqlite3_finalize(S) routine can be called at any point during
5276 ** the life cycle of [prepared statement] S:
5277 ** before statement S is ever evaluated, after
5278 ** one or more calls to [sqlite3_reset()], or after any call
5279 ** to [sqlite3_step()] regardless of whether or not the statement has
5280 ** completed execution.
5282 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
5284 ** The application must finalize every [prepared statement] in order to avoid
5285 ** resource leaks. It is a grievous error for the application to try to use
5286 ** a prepared statement after it has been finalized. Any use of a prepared
5287 ** statement after it has been finalized can result in undefined and
5288 ** undesirable behavior such as segfaults and heap corruption.
5290 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
5293 ** CAPI3REF: Reset A Prepared Statement Object
5294 ** METHOD: sqlite3_stmt
5296 ** The sqlite3_reset() function is called to reset a [prepared statement]
5297 ** object back to its initial state, ready to be re-executed.
5298 ** ^Any SQL statement variables that had values bound to them using
5299 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
5300 ** Use [sqlite3_clear_bindings()] to reset the bindings.
5302 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
5303 ** back to the beginning of its program.
5305 ** ^The return code from [sqlite3_reset(S)] indicates whether or not
5306 ** the previous evaluation of prepared statement S completed successfully.
5307 ** ^If [sqlite3_step(S)] has never before been called on S or if
5308 ** [sqlite3_step(S)] has not been called since the previous call
5309 ** to [sqlite3_reset(S)], then [sqlite3_reset(S)] will return
5312 ** ^If the most recent call to [sqlite3_step(S)] for the
5313 ** [prepared statement] S indicated an error, then
5314 ** [sqlite3_reset(S)] returns an appropriate [error code].
5315 ** ^The [sqlite3_reset(S)] interface might also return an [error code]
5316 ** if there were no prior errors but the process of resetting
5317 ** the prepared statement caused a new error. ^For example, if an
5318 ** [INSERT] statement with a [RETURNING] clause is only stepped one time,
5319 ** that one call to [sqlite3_step(S)] might return SQLITE_ROW but
5320 ** the overall statement might still fail and the [sqlite3_reset(S)] call
5321 ** might return SQLITE_BUSY if locking constraints prevent the
5322 ** database change from committing. Therefore, it is important that
5323 ** applications check the return code from [sqlite3_reset(S)] even if
5324 ** no prior call to [sqlite3_step(S)] indicated a problem.
5326 ** ^The [sqlite3_reset(S)] interface does not change the values
5327 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
5329 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
5333 ** CAPI3REF: Create Or Redefine SQL Functions
5334 ** KEYWORDS: {function creation routines}
5337 ** ^These functions (collectively known as "function creation routines")
5338 ** are used to add SQL functions or aggregates or to redefine the behavior
5339 ** of existing SQL functions or aggregates. The only differences between
5340 ** the three "sqlite3_create_function*" routines are the text encoding
5341 ** expected for the second parameter (the name of the function being
5342 ** created) and the presence or absence of a destructor callback for
5343 ** the application data pointer. Function sqlite3_create_window_function()
5344 ** is similar, but allows the user to supply the extra callback functions
5345 ** needed by [aggregate window functions].
5347 ** ^The first parameter is the [database connection] to which the SQL
5348 ** function is to be added. ^If an application uses more than one database
5349 ** connection then application-defined SQL functions must be added
5350 ** to each database connection separately.
5352 ** ^The second parameter is the name of the SQL function to be created or
5353 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
5354 ** representation, exclusive of the zero-terminator. ^Note that the name
5355 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
5356 ** ^Any attempt to create a function with a longer name
5357 ** will result in [SQLITE_MISUSE] being returned.
5359 ** ^The third parameter (nArg)
5360 ** is the number of arguments that the SQL function or
5361 ** aggregate takes. ^If this parameter is -1, then the SQL function or
5362 ** aggregate may take any number of arguments between 0 and the limit
5363 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
5364 ** parameter is less than -1 or greater than 127 then the behavior is
5367 ** ^The fourth parameter, eTextRep, specifies what
5368 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for
5369 ** its parameters. The application should set this parameter to
5370 ** [SQLITE_UTF16LE] if the function implementation invokes
5371 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
5372 ** implementation invokes [sqlite3_value_text16be()] on an input, or
5373 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
5374 ** otherwise. ^The same SQL function may be registered multiple times using
5375 ** different preferred text encodings, with different implementations for
5377 ** ^When multiple implementations of the same function are available, SQLite
5378 ** will pick the one that involves the least amount of data conversion.
5380 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
5381 ** to signal that the function will always return the same result given
5382 ** the same inputs within a single SQL statement. Most SQL functions are
5383 ** deterministic. The built-in [random()] SQL function is an example of a
5384 ** function that is not deterministic. The SQLite query planner is able to
5385 ** perform additional optimizations on deterministic functions, so use
5386 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
5388 ** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY]
5389 ** flag, which if present prevents the function from being invoked from
5390 ** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions,
5391 ** index expressions, or the WHERE clause of partial indexes.
5393 ** For best security, the [SQLITE_DIRECTONLY] flag is recommended for
5394 ** all application-defined SQL functions that do not need to be
5395 ** used inside of triggers, view, CHECK constraints, or other elements of
5396 ** the database schema. This flags is especially recommended for SQL
5397 ** functions that have side effects or reveal internal application state.
5398 ** Without this flag, an attacker might be able to modify the schema of
5399 ** a database file to include invocations of the function with parameters
5400 ** chosen by the attacker, which the application will then execute when
5401 ** the database file is opened and read.
5403 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the
5404 ** function can gain access to this pointer using [sqlite3_user_data()].)^
5406 ** ^The sixth, seventh and eighth parameters passed to the three
5407 ** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are
5408 ** pointers to C-language functions that implement the SQL function or
5409 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc
5410 ** callback only; NULL pointers must be passed as the xStep and xFinal
5411 ** parameters. ^An aggregate SQL function requires an implementation of xStep
5412 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
5413 ** SQL function or aggregate, pass NULL pointers for all three function
5416 ** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue
5417 ** and xInverse) passed to sqlite3_create_window_function are pointers to
5418 ** C-language callbacks that implement the new function. xStep and xFinal
5419 ** must both be non-NULL. xValue and xInverse may either both be NULL, in
5420 ** which case a regular aggregate function is created, or must both be
5421 ** non-NULL, in which case the new function may be used as either an aggregate
5422 ** or aggregate window function. More details regarding the implementation
5423 ** of aggregate window functions are
5424 ** [user-defined window functions|available here].
5426 ** ^(If the final parameter to sqlite3_create_function_v2() or
5427 ** sqlite3_create_window_function() is not NULL, then it is destructor for
5428 ** the application data pointer. The destructor is invoked when the function
5429 ** is deleted, either by being overloaded or when the database connection
5430 ** closes.)^ ^The destructor is also invoked if the call to
5431 ** sqlite3_create_function_v2() fails. ^When the destructor callback is
5432 ** invoked, it is passed a single argument which is a copy of the application
5433 ** data pointer which was the fifth parameter to sqlite3_create_function_v2().
5435 ** ^It is permitted to register multiple implementations of the same
5436 ** functions with the same name but with either differing numbers of
5437 ** arguments or differing preferred text encodings. ^SQLite will use
5438 ** the implementation that most closely matches the way in which the
5439 ** SQL function is used. ^A function implementation with a non-negative
5440 ** nArg parameter is a better match than a function implementation with
5441 ** a negative nArg. ^A function where the preferred text encoding
5442 ** matches the database encoding is a better
5443 ** match than a function where the encoding is different.
5444 ** ^A function where the encoding difference is between UTF16le and UTF16be
5445 ** is a closer match than a function where the encoding difference is
5446 ** between UTF8 and UTF16.
5448 ** ^Built-in functions may be overloaded by new application-defined functions.
5450 ** ^An application-defined function is permitted to call other
5451 ** SQLite interfaces. However, such calls must not
5452 ** close the database connection nor finalize or reset the prepared
5453 ** statement in which the function is running.
5455 SQLITE_API int sqlite3_create_function(
5457 const char *zFunctionName,
5461 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5462 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5463 void (*xFinal)(sqlite3_context*)
5465 SQLITE_API int sqlite3_create_function16(
5467 const void *zFunctionName,
5471 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5472 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5473 void (*xFinal)(sqlite3_context*)
5475 SQLITE_API int sqlite3_create_function_v2(
5477 const char *zFunctionName,
5481 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5482 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5483 void (*xFinal)(sqlite3_context*),
5484 void(*xDestroy)(void*)
5486 SQLITE_API int sqlite3_create_window_function(
5488 const char *zFunctionName,
5492 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5493 void (*xFinal)(sqlite3_context*),
5494 void (*xValue)(sqlite3_context*),
5495 void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
5496 void(*xDestroy)(void*)
5500 ** CAPI3REF: Text Encodings
5502 ** These constant define integer codes that represent the various
5503 ** text encodings supported by SQLite.
5505 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */
5506 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */
5507 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */
5508 #define SQLITE_UTF16 4 /* Use native byte order */
5509 #define SQLITE_ANY 5 /* Deprecated */
5510 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
5513 ** CAPI3REF: Function Flags
5515 ** These constants may be ORed together with the
5516 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
5517 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or
5518 ** [sqlite3_create_function_v2()].
5521 ** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd>
5522 ** The SQLITE_DETERMINISTIC flag means that the new function always gives
5523 ** the same output when the input parameters are the same.
5524 ** The [abs|abs() function] is deterministic, for example, but
5525 ** [randomblob|randomblob()] is not. Functions must
5526 ** be deterministic in order to be used in certain contexts such as
5527 ** with the WHERE clause of [partial indexes] or in [generated columns].
5528 ** SQLite might also optimize deterministic functions by factoring them
5529 ** out of inner loops.
5532 ** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd>
5533 ** The SQLITE_DIRECTONLY flag means that the function may only be invoked
5534 ** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in
5535 ** schema structures such as [CHECK constraints], [DEFAULT clauses],
5536 ** [expression indexes], [partial indexes], or [generated columns].
5538 ** The SQLITE_DIRECTONLY flag is recommended for any
5539 ** [application-defined SQL function]
5540 ** that has side-effects or that could potentially leak sensitive information.
5541 ** This will prevent attacks in which an application is tricked
5542 ** into using a database file that has had its schema surreptitiously
5543 ** modified to invoke the application-defined function in ways that are
5546 ** Some people say it is good practice to set SQLITE_DIRECTONLY on all
5547 ** [application-defined SQL functions], regardless of whether or not they
5548 ** are security sensitive, as doing so prevents those functions from being used
5549 ** inside of the database schema, and thus ensures that the database
5550 ** can be inspected and modified using generic tools (such as the [CLI])
5551 ** that do not have access to the application-defined functions.
5554 ** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd>
5555 ** The SQLITE_INNOCUOUS flag means that the function is unlikely
5556 ** to cause problems even if misused. An innocuous function should have
5557 ** no side effects and should not depend on any values other than its
5558 ** input parameters. The [abs|abs() function] is an example of an
5559 ** innocuous function.
5560 ** The [load_extension() SQL function] is not innocuous because of its
5562 ** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not
5563 ** exactly the same. The [random|random() function] is an example of a
5564 ** function that is innocuous but not deterministic.
5565 ** <p>Some heightened security settings
5566 ** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF])
5567 ** disable the use of SQL functions inside views and triggers and in
5568 ** schema structures such as [CHECK constraints], [DEFAULT clauses],
5569 ** [expression indexes], [partial indexes], and [generated columns] unless
5570 ** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions
5571 ** are innocuous. Developers are advised to avoid using the
5572 ** SQLITE_INNOCUOUS flag for application-defined functions unless the
5573 ** function has been carefully audited and found to be free of potentially
5574 ** security-adverse side-effects and information-leaks.
5577 ** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd>
5578 ** The SQLITE_SUBTYPE flag indicates to SQLite that a function might call
5579 ** [sqlite3_value_subtype()] to inspect the sub-types of its arguments.
5580 ** This flag instructs SQLite to omit some corner-case optimizations that
5581 ** might disrupt the operation of the [sqlite3_value_subtype()] function,
5582 ** causing it to return zero rather than the correct subtype().
5583 ** SQL functions that invokes [sqlite3_value_subtype()] should have this
5584 ** property. If the SQLITE_SUBTYPE property is omitted, then the return
5585 ** value from [sqlite3_value_subtype()] might sometimes be zero even though
5586 ** a non-zero subtype was specified by the function argument expression.
5588 ** [[SQLITE_RESULT_SUBTYPE]] <dt>SQLITE_RESULT_SUBTYPE</dt><dd>
5589 ** The SQLITE_RESULT_SUBTYPE flag indicates to SQLite that a function might call
5590 ** [sqlite3_result_subtype()] to cause a sub-type to be associated with its
5592 ** Every function that invokes [sqlite3_result_subtype()] should have this
5593 ** property. If it does not, then the call to [sqlite3_result_subtype()]
5594 ** might become a no-op if the function is used as term in an
5595 ** [expression index]. On the other hand, SQL functions that never invoke
5596 ** [sqlite3_result_subtype()] should avoid setting this property, as the
5597 ** purpose of this property is to disable certain optimizations that are
5598 ** incompatible with subtypes.
5602 #define SQLITE_DETERMINISTIC 0x000000800
5603 #define SQLITE_DIRECTONLY 0x000080000
5604 #define SQLITE_SUBTYPE 0x000100000
5605 #define SQLITE_INNOCUOUS 0x000200000
5606 #define SQLITE_RESULT_SUBTYPE 0x001000000
5609 ** CAPI3REF: Deprecated Functions
5612 ** These functions are [deprecated]. In order to maintain
5613 ** backwards compatibility with older code, these functions continue
5614 ** to be supported. However, new applications should avoid
5615 ** the use of these functions. To encourage programmers to avoid
5616 ** these functions, we will not explain what they do.
5618 #ifndef SQLITE_OMIT_DEPRECATED
5619 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
5620 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
5621 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
5622 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
5623 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
5624 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
5625 void*,sqlite3_int64);
5629 ** CAPI3REF: Obtaining SQL Values
5630 ** METHOD: sqlite3_value
5633 ** <blockquote><table border=0 cellpadding=0 cellspacing=0>
5634 ** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value
5635 ** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value
5636 ** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value
5637 ** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value
5638 ** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value
5639 ** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value
5640 ** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in
5641 ** the native byteorder
5642 ** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value
5643 ** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value
5644 ** <tr><td> <td> <td>
5645 ** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB
5646 ** or a UTF-8 TEXT in bytes
5647 ** <tr><td><b>sqlite3_value_bytes16 </b>
5648 ** <td>→ <td>Size of UTF-16
5650 ** <tr><td><b>sqlite3_value_type</b><td>→<td>Default
5651 ** datatype of the value
5652 ** <tr><td><b>sqlite3_value_numeric_type </b>
5653 ** <td>→ <td>Best numeric datatype of the value
5654 ** <tr><td><b>sqlite3_value_nochange </b>
5655 ** <td>→ <td>True if the column is unchanged in an UPDATE
5656 ** against a virtual table.
5657 ** <tr><td><b>sqlite3_value_frombind </b>
5658 ** <td>→ <td>True if value originated from a [bound parameter]
5659 ** </table></blockquote>
5663 ** These routines extract type, size, and content information from
5664 ** [protected sqlite3_value] objects. Protected sqlite3_value objects
5665 ** are used to pass parameter information into the functions that
5666 ** implement [application-defined SQL functions] and [virtual tables].
5668 ** These routines work only with [protected sqlite3_value] objects.
5669 ** Any attempt to use these routines on an [unprotected sqlite3_value]
5670 ** is not threadsafe.
5672 ** ^These routines work just like the corresponding [column access functions]
5673 ** except that these routines take a single [protected sqlite3_value] object
5674 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
5676 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string
5677 ** in the native byte-order of the host machine. ^The
5678 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
5679 ** extract UTF-16 strings as big-endian and little-endian respectively.
5681 ** ^If [sqlite3_value] object V was initialized
5682 ** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)]
5683 ** and if X and Y are strings that compare equal according to strcmp(X,Y),
5684 ** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise,
5685 ** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer()
5686 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
5688 ** ^(The sqlite3_value_type(V) interface returns the
5689 ** [SQLITE_INTEGER | datatype code] for the initial datatype of the
5690 ** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER],
5691 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^
5692 ** Other interfaces might change the datatype for an sqlite3_value object.
5693 ** For example, if the datatype is initially SQLITE_INTEGER and
5694 ** sqlite3_value_text(V) is called to extract a text value for that
5695 ** integer, then subsequent calls to sqlite3_value_type(V) might return
5696 ** SQLITE_TEXT. Whether or not a persistent internal datatype conversion
5697 ** occurs is undefined and may change from one release of SQLite to the next.
5699 ** ^(The sqlite3_value_numeric_type() interface attempts to apply
5700 ** numeric affinity to the value. This means that an attempt is
5701 ** made to convert the value to an integer or floating point. If
5702 ** such a conversion is possible without loss of information (in other
5703 ** words, if the value is a string that looks like a number)
5704 ** then the conversion is performed. Otherwise no conversion occurs.
5705 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
5707 ** ^Within the [xUpdate] method of a [virtual table], the
5708 ** sqlite3_value_nochange(X) interface returns true if and only if
5709 ** the column corresponding to X is unchanged by the UPDATE operation
5710 ** that the xUpdate method call was invoked to implement and if
5711 ** and the prior [xColumn] method call that was invoked to extracted
5712 ** the value for that column returned without setting a result (probably
5713 ** because it queried [sqlite3_vtab_nochange()] and found that the column
5714 ** was unchanging). ^Within an [xUpdate] method, any value for which
5715 ** sqlite3_value_nochange(X) is true will in all other respects appear
5716 ** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other
5717 ** than within an [xUpdate] method call for an UPDATE statement, then
5718 ** the return value is arbitrary and meaningless.
5720 ** ^The sqlite3_value_frombind(X) interface returns non-zero if the
5721 ** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()]
5722 ** interfaces. ^If X comes from an SQL literal value, or a table column,
5723 ** or an expression, then sqlite3_value_frombind(X) returns zero.
5725 ** Please pay particular attention to the fact that the pointer returned
5726 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or
5727 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to
5728 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
5729 ** or [sqlite3_value_text16()].
5731 ** These routines must be called from the same thread as
5732 ** the SQL function that supplied the [sqlite3_value*] parameters.
5734 ** As long as the input parameter is correct, these routines can only
5735 ** fail if an out-of-memory error occurs during a format conversion.
5736 ** Only the following subset of interfaces are subject to out-of-memory
5740 ** <li> sqlite3_value_blob()
5741 ** <li> sqlite3_value_text()
5742 ** <li> sqlite3_value_text16()
5743 ** <li> sqlite3_value_text16le()
5744 ** <li> sqlite3_value_text16be()
5745 ** <li> sqlite3_value_bytes()
5746 ** <li> sqlite3_value_bytes16()
5749 ** If an out-of-memory error occurs, then the return value from these
5750 ** routines is the same as if the column had contained an SQL NULL value.
5751 ** Valid SQL NULL returns can be distinguished from out-of-memory errors
5752 ** by invoking the [sqlite3_errcode()] immediately after the suspect
5753 ** return value is obtained and before any
5754 ** other SQLite interface is called on the same [database connection].
5756 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
5757 SQLITE_API double sqlite3_value_double(sqlite3_value*);
5758 SQLITE_API int sqlite3_value_int(sqlite3_value*);
5759 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
5760 SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*);
5761 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
5762 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
5763 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
5764 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
5765 SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
5766 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
5767 SQLITE_API int sqlite3_value_type(sqlite3_value*);
5768 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
5769 SQLITE_API int sqlite3_value_nochange(sqlite3_value*);
5770 SQLITE_API int sqlite3_value_frombind(sqlite3_value*);
5773 ** CAPI3REF: Report the internal text encoding state of an sqlite3_value object
5774 ** METHOD: sqlite3_value
5776 ** ^(The sqlite3_value_encoding(X) interface returns one of [SQLITE_UTF8],
5777 ** [SQLITE_UTF16BE], or [SQLITE_UTF16LE] according to the current text encoding
5778 ** of the value X, assuming that X has type TEXT.)^ If sqlite3_value_type(X)
5779 ** returns something other than SQLITE_TEXT, then the return value from
5780 ** sqlite3_value_encoding(X) is meaningless. ^Calls to
5781 ** [sqlite3_value_text(X)], [sqlite3_value_text16(X)], [sqlite3_value_text16be(X)],
5782 ** [sqlite3_value_text16le(X)], [sqlite3_value_bytes(X)], or
5783 ** [sqlite3_value_bytes16(X)] might change the encoding of the value X and
5784 ** thus change the return from subsequent calls to sqlite3_value_encoding(X).
5786 ** This routine is intended for used by applications that test and validate
5787 ** the SQLite implementation. This routine is inquiring about the opaque
5788 ** internal state of an [sqlite3_value] object. Ordinary applications should
5789 ** not need to know what the internal state of an sqlite3_value object is and
5790 ** hence should not need to use this interface.
5792 SQLITE_API int sqlite3_value_encoding(sqlite3_value*);
5795 ** CAPI3REF: Finding The Subtype Of SQL Values
5796 ** METHOD: sqlite3_value
5798 ** The sqlite3_value_subtype(V) function returns the subtype for
5799 ** an [application-defined SQL function] argument V. The subtype
5800 ** information can be used to pass a limited amount of context from
5801 ** one SQL function to another. Use the [sqlite3_result_subtype()]
5802 ** routine to set the subtype for the return value of an SQL function.
5804 ** Every [application-defined SQL function] that invoke this interface
5805 ** should include the [SQLITE_SUBTYPE] property in the text
5806 ** encoding argument when the function is [sqlite3_create_function|registered].
5807 ** If the [SQLITE_SUBTYPE] property is omitted, then sqlite3_value_subtype()
5808 ** might return zero instead of the upstream subtype in some corner cases.
5810 SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*);
5813 ** CAPI3REF: Copy And Free SQL Values
5814 ** METHOD: sqlite3_value
5816 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
5817 ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned
5818 ** is a [protected sqlite3_value] object even if the input is not.
5819 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
5820 ** memory allocation fails. ^If V is a [pointer value], then the result
5821 ** of sqlite3_value_dup(V) is a NULL value.
5823 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
5824 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer
5825 ** then sqlite3_value_free(V) is a harmless no-op.
5827 SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*);
5828 SQLITE_API void sqlite3_value_free(sqlite3_value*);
5831 ** CAPI3REF: Obtain Aggregate Function Context
5832 ** METHOD: sqlite3_context
5834 ** Implementations of aggregate SQL functions use this
5835 ** routine to allocate memory for storing their state.
5837 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called
5838 ** for a particular aggregate function, SQLite allocates
5839 ** N bytes of memory, zeroes out that memory, and returns a pointer
5840 ** to the new memory. ^On second and subsequent calls to
5841 ** sqlite3_aggregate_context() for the same aggregate function instance,
5842 ** the same buffer is returned. Sqlite3_aggregate_context() is normally
5843 ** called once for each invocation of the xStep callback and then one
5844 ** last time when the xFinal callback is invoked. ^(When no rows match
5845 ** an aggregate query, the xStep() callback of the aggregate function
5846 ** implementation is never called and xFinal() is called exactly once.
5847 ** In those cases, sqlite3_aggregate_context() might be called for the
5848 ** first time from within xFinal().)^
5850 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
5851 ** when first called if N is less than or equal to zero or if a memory
5852 ** allocation error occurs.
5854 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
5855 ** determined by the N parameter on first successful call. Changing the
5856 ** value of N in any subsequent call to sqlite3_aggregate_context() within
5857 ** the same aggregate function instance will not resize the memory
5858 ** allocation.)^ Within the xFinal callback, it is customary to set
5859 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
5860 ** pointless memory allocations occur.
5862 ** ^SQLite automatically frees the memory allocated by
5863 ** sqlite3_aggregate_context() when the aggregate query concludes.
5865 ** The first parameter must be a copy of the
5866 ** [sqlite3_context | SQL function context] that is the first parameter
5867 ** to the xStep or xFinal callback routine that implements the aggregate
5870 ** This routine must be called from the same thread in which
5871 ** the aggregate SQL function is running.
5873 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
5876 ** CAPI3REF: User Data For Functions
5877 ** METHOD: sqlite3_context
5879 ** ^The sqlite3_user_data() interface returns a copy of
5880 ** the pointer that was the pUserData parameter (the 5th parameter)
5881 ** of the [sqlite3_create_function()]
5882 ** and [sqlite3_create_function16()] routines that originally
5883 ** registered the application defined function.
5885 ** This routine must be called from the same thread in which
5886 ** the application-defined function is running.
5888 SQLITE_API void *sqlite3_user_data(sqlite3_context*);
5891 ** CAPI3REF: Database Connection For Functions
5892 ** METHOD: sqlite3_context
5894 ** ^The sqlite3_context_db_handle() interface returns a copy of
5895 ** the pointer to the [database connection] (the 1st parameter)
5896 ** of the [sqlite3_create_function()]
5897 ** and [sqlite3_create_function16()] routines that originally
5898 ** registered the application defined function.
5900 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
5903 ** CAPI3REF: Function Auxiliary Data
5904 ** METHOD: sqlite3_context
5906 ** These functions may be used by (non-aggregate) SQL functions to
5907 ** associate auxiliary data with argument values. If the same argument
5908 ** value is passed to multiple invocations of the same SQL function during
5909 ** query execution, under some circumstances the associated auxiliary data
5910 ** might be preserved. An example of where this might be useful is in a
5911 ** regular-expression matching function. The compiled version of the regular
5912 ** expression can be stored as auxiliary data associated with the pattern string.
5913 ** Then as long as the pattern string remains the same,
5914 ** the compiled regular expression can be reused on multiple
5915 ** invocations of the same function.
5917 ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the auxiliary data
5918 ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument
5919 ** value to the application-defined function. ^N is zero for the left-most
5920 ** function argument. ^If there is no auxiliary data
5921 ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface
5922 ** returns a NULL pointer.
5924 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as auxiliary data for the
5925 ** N-th argument of the application-defined function. ^Subsequent
5926 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent
5927 ** sqlite3_set_auxdata(C,N,P,X) call if the auxiliary data is still valid or
5928 ** NULL if the auxiliary data has been discarded.
5929 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
5930 ** SQLite will invoke the destructor function X with parameter P exactly
5931 ** once, when the auxiliary data is discarded.
5932 ** SQLite is free to discard the auxiliary data at any time, including: <ul>
5933 ** <li> ^(when the corresponding function parameter changes)^, or
5934 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
5935 ** SQL statement)^, or
5936 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same
5938 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory
5939 ** allocation error occurs.)^
5940 ** <li> ^(during the original sqlite3_set_auxdata() call if the function
5941 ** is evaluated during query planning instead of during query execution,
5942 ** as sometimes happens with [SQLITE_ENABLE_STAT4].)^ </ul>
5944 ** Note the last two bullets in particular. The destructor X in
5945 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
5946 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata()
5947 ** should be called near the end of the function implementation and the
5948 ** function implementation should not make any use of P after
5949 ** sqlite3_set_auxdata() has been called. Furthermore, a call to
5950 ** sqlite3_get_auxdata() that occurs immediately after a corresponding call
5951 ** to sqlite3_set_auxdata() might still return NULL if an out-of-memory
5952 ** condition occurred during the sqlite3_set_auxdata() call or if the
5953 ** function is being evaluated during query planning rather than during
5956 ** ^(In practice, auxiliary data is preserved between function calls for
5957 ** function parameters that are compile-time constants, including literal
5958 ** values and [parameters] and expressions composed from the same.)^
5960 ** The value of the N parameter to these interfaces should be non-negative.
5961 ** Future enhancements may make use of negative N values to define new
5962 ** kinds of function caching behavior.
5964 ** These routines must be called from the same thread in which
5965 ** the SQL function is running.
5967 ** See also: [sqlite3_get_clientdata()] and [sqlite3_set_clientdata()].
5969 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
5970 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
5973 ** CAPI3REF: Database Connection Client Data
5976 ** These functions are used to associate one or more named pointers
5977 ** with a [database connection].
5978 ** A call to sqlite3_set_clientdata(D,N,P,X) causes the pointer P
5979 ** to be attached to [database connection] D using name N. Subsequent
5980 ** calls to sqlite3_get_clientdata(D,N) will return a copy of pointer P
5981 ** or a NULL pointer if there were no prior calls to
5982 ** sqlite3_set_clientdata() with the same values of D and N.
5983 ** Names are compared using strcmp() and are thus case sensitive.
5985 ** If P and X are both non-NULL, then the destructor X is invoked with
5986 ** argument P on the first of the following occurrences:
5988 ** <li> An out-of-memory error occurs during the call to
5989 ** sqlite3_set_clientdata() which attempts to register pointer P.
5990 ** <li> A subsequent call to sqlite3_set_clientdata(D,N,P,X) is made
5991 ** with the same D and N parameters.
5992 ** <li> The database connection closes. SQLite does not make any guarantees
5993 ** about the order in which destructors are called, only that all
5994 ** destructors will be called exactly once at some point during the
5995 ** database connection closing process.
5998 ** SQLite does not do anything with client data other than invoke
5999 ** destructors on the client data at the appropriate time. The intended
6000 ** use for client data is to provide a mechanism for wrapper libraries
6001 ** to store additional information about an SQLite database connection.
6003 ** There is no limit (other than available memory) on the number of different
6004 ** client data pointers (with different names) that can be attached to a
6005 ** single database connection. However, the implementation is optimized
6006 ** for the case of having only one or two different client data names.
6007 ** Applications and wrapper libraries are discouraged from using more than
6008 ** one client data name each.
6010 ** There is no way to enumerate the client data pointers
6011 ** associated with a database connection. The N parameter can be thought
6012 ** of as a secret key such that only code that knows the secret key is able
6013 ** to access the associated data.
6015 ** Security Warning: These interfaces should not be exposed in scripting
6016 ** languages or in other circumstances where it might be possible for an
6017 ** an attacker to invoke them. Any agent that can invoke these interfaces
6018 ** can probably also take control of the process.
6020 ** Database connection client data is only available for SQLite
6021 ** version 3.44.0 ([dateof:3.44.0]) and later.
6023 ** See also: [sqlite3_set_auxdata()] and [sqlite3_get_auxdata()].
6025 SQLITE_API void *sqlite3_get_clientdata(sqlite3*,const char*);
6026 SQLITE_API int sqlite3_set_clientdata(sqlite3*, const char*, void*, void(*)(void*));
6029 ** CAPI3REF: Constants Defining Special Destructor Behavior
6031 ** These are special values for the destructor that is passed in as the
6032 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
6033 ** argument is SQLITE_STATIC, it means that the content pointer is constant
6034 ** and will never change. It does not need to be destroyed. ^The
6035 ** SQLITE_TRANSIENT value means that the content will likely change in
6036 ** the near future and that SQLite should make its own private copy of
6037 ** the content before returning.
6039 ** The typedef is necessary to work around problems in certain
6042 typedef void (*sqlite3_destructor_type)(void*);
6043 #define SQLITE_STATIC ((sqlite3_destructor_type)0)
6044 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
6047 ** CAPI3REF: Setting The Result Of An SQL Function
6048 ** METHOD: sqlite3_context
6050 ** These routines are used by the xFunc or xFinal callbacks that
6051 ** implement SQL functions and aggregates. See
6052 ** [sqlite3_create_function()] and [sqlite3_create_function16()]
6053 ** for additional information.
6055 ** These functions work very much like the [parameter binding] family of
6056 ** functions used to bind values to host parameters in prepared statements.
6057 ** Refer to the [SQL parameter] documentation for additional information.
6059 ** ^The sqlite3_result_blob() interface sets the result from
6060 ** an application-defined function to be the BLOB whose content is pointed
6061 ** to by the second parameter and which is N bytes long where N is the
6064 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
6065 ** interfaces set the result of the application-defined function to be
6066 ** a BLOB containing all zero bytes and N bytes in size.
6068 ** ^The sqlite3_result_double() interface sets the result from
6069 ** an application-defined function to be a floating point value specified
6070 ** by its 2nd argument.
6072 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions
6073 ** cause the implemented SQL function to throw an exception.
6074 ** ^SQLite uses the string pointed to by the
6075 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
6076 ** as the text of an error message. ^SQLite interprets the error
6077 ** message string from sqlite3_result_error() as UTF-8. ^SQLite
6078 ** interprets the string from sqlite3_result_error16() as UTF-16 using
6079 ** the same [byte-order determination rules] as [sqlite3_bind_text16()].
6080 ** ^If the third parameter to sqlite3_result_error()
6081 ** or sqlite3_result_error16() is negative then SQLite takes as the error
6082 ** message all text up through the first zero character.
6083 ** ^If the third parameter to sqlite3_result_error() or
6084 ** sqlite3_result_error16() is non-negative then SQLite takes that many
6085 ** bytes (not characters) from the 2nd parameter as the error message.
6086 ** ^The sqlite3_result_error() and sqlite3_result_error16()
6087 ** routines make a private copy of the error message text before
6088 ** they return. Hence, the calling function can deallocate or
6089 ** modify the text after they return without harm.
6090 ** ^The sqlite3_result_error_code() function changes the error code
6091 ** returned by SQLite as a result of an error in a function. ^By default,
6092 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
6093 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
6095 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
6096 ** error indicating that a string or BLOB is too long to represent.
6098 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
6099 ** error indicating that a memory allocation failed.
6101 ** ^The sqlite3_result_int() interface sets the return value
6102 ** of the application-defined function to be the 32-bit signed integer
6103 ** value given in the 2nd argument.
6104 ** ^The sqlite3_result_int64() interface sets the return value
6105 ** of the application-defined function to be the 64-bit signed integer
6106 ** value given in the 2nd argument.
6108 ** ^The sqlite3_result_null() interface sets the return value
6109 ** of the application-defined function to be NULL.
6111 ** ^The sqlite3_result_text(), sqlite3_result_text16(),
6112 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
6113 ** set the return value of the application-defined function to be
6114 ** a text string which is represented as UTF-8, UTF-16 native byte order,
6115 ** UTF-16 little endian, or UTF-16 big endian, respectively.
6116 ** ^The sqlite3_result_text64() interface sets the return value of an
6117 ** application-defined function to be a text string in an encoding
6118 ** specified by the fifth (and last) parameter, which must be one
6119 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE].
6120 ** ^SQLite takes the text result from the application from
6121 ** the 2nd parameter of the sqlite3_result_text* interfaces.
6122 ** ^If the 3rd parameter to any of the sqlite3_result_text* interfaces
6123 ** other than sqlite3_result_text64() is negative, then SQLite computes
6124 ** the string length itself by searching the 2nd parameter for the first
6126 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
6127 ** is non-negative, then as many bytes (not characters) of the text
6128 ** pointed to by the 2nd parameter are taken as the application-defined
6129 ** function result. If the 3rd parameter is non-negative, then it
6130 ** must be the byte offset into the string where the NUL terminator would
6131 ** appear if the string where NUL terminated. If any NUL characters occur
6132 ** in the string at a byte offset that is less than the value of the 3rd
6133 ** parameter, then the resulting string will contain embedded NULs and the
6134 ** result of expressions operating on strings with embedded NULs is undefined.
6135 ** ^If the 4th parameter to the sqlite3_result_text* interfaces
6136 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
6137 ** function as the destructor on the text or BLOB result when it has
6138 ** finished using that result.
6139 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
6140 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
6141 ** assumes that the text or BLOB result is in constant space and does not
6142 ** copy the content of the parameter nor call a destructor on the content
6143 ** when it has finished using that result.
6144 ** ^If the 4th parameter to the sqlite3_result_text* interfaces
6145 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
6146 ** then SQLite makes a copy of the result into space obtained
6147 ** from [sqlite3_malloc()] before it returns.
6149 ** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and
6150 ** sqlite3_result_text16be() routines, and for sqlite3_result_text64()
6151 ** when the encoding is not UTF8, if the input UTF16 begins with a
6152 ** byte-order mark (BOM, U+FEFF) then the BOM is removed from the
6153 ** string and the rest of the string is interpreted according to the
6154 ** byte-order specified by the BOM. ^The byte-order specified by
6155 ** the BOM at the beginning of the text overrides the byte-order
6156 ** specified by the interface procedure. ^So, for example, if
6157 ** sqlite3_result_text16le() is invoked with text that begins
6158 ** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the
6159 ** first two bytes of input are skipped and the remaining input
6160 ** is interpreted as UTF16BE text.
6162 ** ^For UTF16 input text to the sqlite3_result_text16(),
6163 ** sqlite3_result_text16be(), sqlite3_result_text16le(), and
6164 ** sqlite3_result_text64() routines, if the text contains invalid
6165 ** UTF16 characters, the invalid characters might be converted
6166 ** into the unicode replacement character, U+FFFD.
6168 ** ^The sqlite3_result_value() interface sets the result of
6169 ** the application-defined function to be a copy of the
6170 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
6171 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
6172 ** so that the [sqlite3_value] specified in the parameter may change or
6173 ** be deallocated after sqlite3_result_value() returns without harm.
6174 ** ^A [protected sqlite3_value] object may always be used where an
6175 ** [unprotected sqlite3_value] object is required, so either
6176 ** kind of [sqlite3_value] object can be used with this interface.
6178 ** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an
6179 ** SQL NULL value, just like [sqlite3_result_null(C)], except that it
6180 ** also associates the host-language pointer P or type T with that
6181 ** NULL value such that the pointer can be retrieved within an
6182 ** [application-defined SQL function] using [sqlite3_value_pointer()].
6183 ** ^If the D parameter is not NULL, then it is a pointer to a destructor
6184 ** for the P parameter. ^SQLite invokes D with P as its only argument
6185 ** when SQLite is finished with P. The T parameter should be a static
6186 ** string and preferably a string literal. The sqlite3_result_pointer()
6187 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
6189 ** If these routines are called from within the different thread
6190 ** than the one containing the application-defined function that received
6191 ** the [sqlite3_context] pointer, the results are undefined.
6193 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
6194 SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*,
6195 sqlite3_uint64,void(*)(void*));
6196 SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
6197 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
6198 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
6199 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
6200 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
6201 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
6202 SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
6203 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
6204 SQLITE_API void sqlite3_result_null(sqlite3_context*);
6205 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
6206 SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64,
6207 void(*)(void*), unsigned char encoding);
6208 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
6209 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
6210 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
6211 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
6212 SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*));
6213 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
6214 SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
6218 ** CAPI3REF: Setting The Subtype Of An SQL Function
6219 ** METHOD: sqlite3_context
6221 ** The sqlite3_result_subtype(C,T) function causes the subtype of
6222 ** the result from the [application-defined SQL function] with
6223 ** [sqlite3_context] C to be the value T. Only the lower 8 bits
6224 ** of the subtype T are preserved in current versions of SQLite;
6225 ** higher order bits are discarded.
6226 ** The number of subtype bytes preserved by SQLite might increase
6227 ** in future releases of SQLite.
6229 ** Every [application-defined SQL function] that invokes this interface
6230 ** should include the [SQLITE_RESULT_SUBTYPE] property in its
6231 ** text encoding argument when the SQL function is
6232 ** [sqlite3_create_function|registered]. If the [SQLITE_RESULT_SUBTYPE]
6233 ** property is omitted from the function that invokes sqlite3_result_subtype(),
6234 ** then in some cases the sqlite3_result_subtype() might fail to set
6235 ** the result subtype.
6237 ** If SQLite is compiled with -DSQLITE_STRICT_SUBTYPE=1, then any
6238 ** SQL function that invokes the sqlite3_result_subtype() interface
6239 ** and that does not have the SQLITE_RESULT_SUBTYPE property will raise
6240 ** an error. Future versions of SQLite might enable -DSQLITE_STRICT_SUBTYPE=1
6243 SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int);
6246 ** CAPI3REF: Define New Collating Sequences
6249 ** ^These functions add, remove, or modify a [collation] associated
6250 ** with the [database connection] specified as the first argument.
6252 ** ^The name of the collation is a UTF-8 string
6253 ** for sqlite3_create_collation() and sqlite3_create_collation_v2()
6254 ** and a UTF-16 string in native byte order for sqlite3_create_collation16().
6255 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
6256 ** considered to be the same name.
6258 ** ^(The third argument (eTextRep) must be one of the constants:
6260 ** <li> [SQLITE_UTF8],
6261 ** <li> [SQLITE_UTF16LE],
6262 ** <li> [SQLITE_UTF16BE],
6263 ** <li> [SQLITE_UTF16], or
6264 ** <li> [SQLITE_UTF16_ALIGNED].
6266 ** ^The eTextRep argument determines the encoding of strings passed
6267 ** to the collating function callback, xCompare.
6268 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
6269 ** force strings to be UTF16 with native byte order.
6270 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
6271 ** on an even byte address.
6273 ** ^The fourth argument, pArg, is an application data pointer that is passed
6274 ** through as the first argument to the collating function callback.
6276 ** ^The fifth argument, xCompare, is a pointer to the collating function.
6277 ** ^Multiple collating functions can be registered using the same name but
6278 ** with different eTextRep parameters and SQLite will use whichever
6279 ** function requires the least amount of data transformation.
6280 ** ^If the xCompare argument is NULL then the collating function is
6281 ** deleted. ^When all collating functions having the same name are deleted,
6282 ** that collation is no longer usable.
6284 ** ^The collating function callback is invoked with a copy of the pArg
6285 ** application data pointer and with two strings in the encoding specified
6286 ** by the eTextRep argument. The two integer parameters to the collating
6287 ** function callback are the length of the two strings, in bytes. The collating
6288 ** function must return an integer that is negative, zero, or positive
6289 ** if the first string is less than, equal to, or greater than the second,
6290 ** respectively. A collating function must always return the same answer
6291 ** given the same inputs. If two or more collating functions are registered
6292 ** to the same collation name (using different eTextRep values) then all
6293 ** must give an equivalent answer when invoked with equivalent strings.
6294 ** The collating function must obey the following properties for all
6295 ** strings A, B, and C:
6298 ** <li> If A==B then B==A.
6299 ** <li> If A==B and B==C then A==C.
6300 ** <li> If A<B THEN B>A.
6301 ** <li> If A<B and B<C then A<C.
6304 ** If a collating function fails any of the above constraints and that
6305 ** collating function is registered and used, then the behavior of SQLite
6308 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
6309 ** with the addition that the xDestroy callback is invoked on pArg when
6310 ** the collating function is deleted.
6311 ** ^Collating functions are deleted when they are overridden by later
6312 ** calls to the collation creation functions or when the
6313 ** [database connection] is closed using [sqlite3_close()].
6315 ** ^The xDestroy callback is <u>not</u> called if the
6316 ** sqlite3_create_collation_v2() function fails. Applications that invoke
6317 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
6318 ** check the return code and dispose of the application data pointer
6319 ** themselves rather than expecting SQLite to deal with it for them.
6320 ** This is different from every other SQLite interface. The inconsistency
6321 ** is unfortunate but cannot be changed without breaking backwards
6324 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
6326 SQLITE_API int sqlite3_create_collation(
6331 int(*xCompare)(void*,int,const void*,int,const void*)
6333 SQLITE_API int sqlite3_create_collation_v2(
6338 int(*xCompare)(void*,int,const void*,int,const void*),
6339 void(*xDestroy)(void*)
6341 SQLITE_API int sqlite3_create_collation16(
6346 int(*xCompare)(void*,int,const void*,int,const void*)
6350 ** CAPI3REF: Collation Needed Callbacks
6353 ** ^To avoid having to register all collation sequences before a database
6354 ** can be used, a single callback function may be registered with the
6355 ** [database connection] to be invoked whenever an undefined collation
6356 ** sequence is required.
6358 ** ^If the function is registered using the sqlite3_collation_needed() API,
6359 ** then it is passed the names of undefined collation sequences as strings
6360 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
6361 ** the names are passed as UTF-16 in machine native byte order.
6362 ** ^A call to either function replaces the existing collation-needed callback.
6364 ** ^(When the callback is invoked, the first argument passed is a copy
6365 ** of the second argument to sqlite3_collation_needed() or
6366 ** sqlite3_collation_needed16(). The second argument is the database
6367 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
6368 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
6369 ** sequence function required. The fourth parameter is the name of the
6370 ** required collation sequence.)^
6372 ** The callback function should register the desired collation using
6373 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
6374 ** [sqlite3_create_collation_v2()].
6376 SQLITE_API int sqlite3_collation_needed(
6379 void(*)(void*,sqlite3*,int eTextRep,const char*)
6381 SQLITE_API int sqlite3_collation_needed16(
6384 void(*)(void*,sqlite3*,int eTextRep,const void*)
6387 #ifdef SQLITE_ENABLE_CEROD
6389 ** Specify the activation key for a CEROD database. Unless
6390 ** activated, none of the CEROD routines will work.
6392 SQLITE_API void sqlite3_activate_cerod(
6393 const char *zPassPhrase /* Activation phrase */
6398 ** CAPI3REF: Suspend Execution For A Short Time
6400 ** The sqlite3_sleep() function causes the current thread to suspend execution
6401 ** for at least a number of milliseconds specified in its parameter.
6403 ** If the operating system does not support sleep requests with
6404 ** millisecond time resolution, then the time will be rounded up to
6405 ** the nearest second. The number of milliseconds of sleep actually
6406 ** requested from the operating system is returned.
6408 ** ^SQLite implements this interface by calling the xSleep()
6409 ** method of the default [sqlite3_vfs] object. If the xSleep() method
6410 ** of the default VFS is not implemented correctly, or not implemented at
6411 ** all, then the behavior of sqlite3_sleep() may deviate from the description
6412 ** in the previous paragraphs.
6414 ** If a negative argument is passed to sqlite3_sleep() the results vary by
6415 ** VFS and operating system. Some system treat a negative argument as an
6416 ** instruction to sleep forever. Others understand it to mean do not sleep
6417 ** at all. ^In SQLite version 3.42.0 and later, a negative
6418 ** argument passed into sqlite3_sleep() is changed to zero before it is relayed
6419 ** down into the xSleep method of the VFS.
6421 SQLITE_API int sqlite3_sleep(int);
6424 ** CAPI3REF: Name Of The Folder Holding Temporary Files
6426 ** ^(If this global variable is made to point to a string which is
6427 ** the name of a folder (a.k.a. directory), then all temporary files
6428 ** created by SQLite when using a built-in [sqlite3_vfs | VFS]
6429 ** will be placed in that directory.)^ ^If this variable
6430 ** is a NULL pointer, then SQLite performs a search for an appropriate
6431 ** temporary file directory.
6433 ** Applications are strongly discouraged from using this global variable.
6434 ** It is required to set a temporary folder on Windows Runtime (WinRT).
6435 ** But for all other platforms, it is highly recommended that applications
6436 ** neither read nor write this variable. This global variable is a relic
6437 ** that exists for backwards compatibility of legacy applications and should
6438 ** be avoided in new projects.
6440 ** It is not safe to read or modify this variable in more than one
6441 ** thread at a time. It is not safe to read or modify this variable
6442 ** if a [database connection] is being used at the same time in a separate
6444 ** It is intended that this variable be set once
6445 ** as part of process initialization and before any SQLite interface
6446 ** routines have been called and that this variable remain unchanged
6449 ** ^The [temp_store_directory pragma] may modify this variable and cause
6450 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6451 ** the [temp_store_directory pragma] always assumes that any string
6452 ** that this variable points to is held in memory obtained from
6453 ** [sqlite3_malloc] and the pragma may attempt to free that memory
6454 ** using [sqlite3_free].
6455 ** Hence, if this variable is modified directly, either it should be
6456 ** made NULL or made to point to memory obtained from [sqlite3_malloc]
6457 ** or else the use of the [temp_store_directory pragma] should be avoided.
6458 ** Except when requested by the [temp_store_directory pragma], SQLite
6459 ** does not free the memory that sqlite3_temp_directory points to. If
6460 ** the application wants that memory to be freed, it must do
6461 ** so itself, taking care to only do so after all [database connection]
6462 ** objects have been destroyed.
6464 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set
6465 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
6466 ** features that require the use of temporary files may fail. Here is an
6467 ** example of how to do this using C++ with the Windows Runtime:
6469 ** <blockquote><pre>
6470 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
6471 ** TemporaryFolder->Path->Data();
6472 ** char zPathBuf[MAX_PATH + 1];
6473 ** memset(zPathBuf, 0, sizeof(zPathBuf));
6474 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
6475 ** NULL, NULL);
6476 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
6477 ** </pre></blockquote>
6479 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
6482 ** CAPI3REF: Name Of The Folder Holding Database Files
6484 ** ^(If this global variable is made to point to a string which is
6485 ** the name of a folder (a.k.a. directory), then all database files
6486 ** specified with a relative pathname and created or accessed by
6487 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
6488 ** to be relative to that directory.)^ ^If this variable is a NULL
6489 ** pointer, then SQLite assumes that all database files specified
6490 ** with a relative pathname are relative to the current directory
6491 ** for the process. Only the windows VFS makes use of this global
6492 ** variable; it is ignored by the unix VFS.
6494 ** Changing the value of this variable while a database connection is
6495 ** open can result in a corrupt database.
6497 ** It is not safe to read or modify this variable in more than one
6498 ** thread at a time. It is not safe to read or modify this variable
6499 ** if a [database connection] is being used at the same time in a separate
6501 ** It is intended that this variable be set once
6502 ** as part of process initialization and before any SQLite interface
6503 ** routines have been called and that this variable remain unchanged
6506 ** ^The [data_store_directory pragma] may modify this variable and cause
6507 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6508 ** the [data_store_directory pragma] always assumes that any string
6509 ** that this variable points to is held in memory obtained from
6510 ** [sqlite3_malloc] and the pragma may attempt to free that memory
6511 ** using [sqlite3_free].
6512 ** Hence, if this variable is modified directly, either it should be
6513 ** made NULL or made to point to memory obtained from [sqlite3_malloc]
6514 ** or else the use of the [data_store_directory pragma] should be avoided.
6516 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
6519 ** CAPI3REF: Win32 Specific Interface
6521 ** These interfaces are available only on Windows. The
6522 ** [sqlite3_win32_set_directory] interface is used to set the value associated
6523 ** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to
6524 ** zValue, depending on the value of the type parameter. The zValue parameter
6525 ** should be NULL to cause the previous value to be freed via [sqlite3_free];
6526 ** a non-NULL value will be copied into memory obtained from [sqlite3_malloc]
6527 ** prior to being used. The [sqlite3_win32_set_directory] interface returns
6528 ** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported,
6529 ** or [SQLITE_NOMEM] if memory could not be allocated. The value of the
6530 ** [sqlite3_data_directory] variable is intended to act as a replacement for
6531 ** the current directory on the sub-platforms of Win32 where that concept is
6532 ** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and
6533 ** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the
6534 ** sqlite3_win32_set_directory interface except the string parameter must be
6535 ** UTF-8 or UTF-16, respectively.
6537 SQLITE_API int sqlite3_win32_set_directory(
6538 unsigned long type, /* Identifier for directory being set or reset */
6539 void *zValue /* New value for directory being set or reset */
6541 SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue);
6542 SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue);
6545 ** CAPI3REF: Win32 Directory Types
6547 ** These macros are only available on Windows. They define the allowed values
6548 ** for the type argument to the [sqlite3_win32_set_directory] interface.
6550 #define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1
6551 #define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2
6554 ** CAPI3REF: Test For Auto-Commit Mode
6555 ** KEYWORDS: {autocommit mode}
6558 ** ^The sqlite3_get_autocommit() interface returns non-zero or
6559 ** zero if the given database connection is or is not in autocommit mode,
6560 ** respectively. ^Autocommit mode is on by default.
6561 ** ^Autocommit mode is disabled by a [BEGIN] statement.
6562 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
6564 ** If certain kinds of errors occur on a statement within a multi-statement
6565 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
6566 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
6567 ** transaction might be rolled back automatically. The only way to
6568 ** find out whether SQLite automatically rolled back the transaction after
6569 ** an error is to use this function.
6571 ** If another thread changes the autocommit status of the database
6572 ** connection while this routine is running, then the return value
6575 SQLITE_API int sqlite3_get_autocommit(sqlite3*);
6578 ** CAPI3REF: Find The Database Handle Of A Prepared Statement
6579 ** METHOD: sqlite3_stmt
6581 ** ^The sqlite3_db_handle interface returns the [database connection] handle
6582 ** to which a [prepared statement] belongs. ^The [database connection]
6583 ** returned by sqlite3_db_handle is the same [database connection]
6584 ** that was the first argument
6585 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
6586 ** create the statement in the first place.
6588 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
6591 ** CAPI3REF: Return The Schema Name For A Database Connection
6594 ** ^The sqlite3_db_name(D,N) interface returns a pointer to the schema name
6595 ** for the N-th database on database connection D, or a NULL pointer of N is
6596 ** out of range. An N value of 0 means the main database file. An N of 1 is
6597 ** the "temp" schema. Larger values of N correspond to various ATTACH-ed
6600 ** Space to hold the string that is returned by sqlite3_db_name() is managed
6601 ** by SQLite itself. The string might be deallocated by any operation that
6602 ** changes the schema, including [ATTACH] or [DETACH] or calls to
6603 ** [sqlite3_serialize()] or [sqlite3_deserialize()], even operations that
6604 ** occur on a different thread. Applications that need to
6605 ** remember the string long-term should make their own copy. Applications that
6606 ** are accessing the same database connection simultaneously on multiple
6607 ** threads should mutex-protect calls to this API and should make their own
6608 ** private copy of the result prior to releasing the mutex.
6610 SQLITE_API const char *sqlite3_db_name(sqlite3 *db, int N);
6613 ** CAPI3REF: Return The Filename For A Database Connection
6616 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename
6617 ** associated with database N of connection D.
6618 ** ^If there is no attached database N on the database
6619 ** connection D, or if database N is a temporary or in-memory database, then
6620 ** this function will return either a NULL pointer or an empty string.
6622 ** ^The string value returned by this routine is owned and managed by
6623 ** the database connection. ^The value will be valid until the database N
6624 ** is [DETACH]-ed or until the database connection closes.
6626 ** ^The filename returned by this function is the output of the
6627 ** xFullPathname method of the [VFS]. ^In other words, the filename
6628 ** will be an absolute pathname, even if the filename used
6629 ** to open the database originally was a URI or relative pathname.
6631 ** If the filename pointer returned by this routine is not NULL, then it
6632 ** can be used as the filename input parameter to these routines:
6634 ** <li> [sqlite3_uri_parameter()]
6635 ** <li> [sqlite3_uri_boolean()]
6636 ** <li> [sqlite3_uri_int64()]
6637 ** <li> [sqlite3_filename_database()]
6638 ** <li> [sqlite3_filename_journal()]
6639 ** <li> [sqlite3_filename_wal()]
6642 SQLITE_API sqlite3_filename sqlite3_db_filename(sqlite3 *db, const char *zDbName);
6645 ** CAPI3REF: Determine if a database is read-only
6648 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
6649 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not
6650 ** the name of a database on connection D.
6652 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
6655 ** CAPI3REF: Determine the transaction state of a database
6658 ** ^The sqlite3_txn_state(D,S) interface returns the current
6659 ** [transaction state] of schema S in database connection D. ^If S is NULL,
6660 ** then the highest transaction state of any schema on database connection D
6661 ** is returned. Transaction states are (in order of lowest to highest):
6663 ** <li value="0"> SQLITE_TXN_NONE
6664 ** <li value="1"> SQLITE_TXN_READ
6665 ** <li value="2"> SQLITE_TXN_WRITE
6667 ** ^If the S argument to sqlite3_txn_state(D,S) is not the name of
6668 ** a valid schema, then -1 is returned.
6670 SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema);
6673 ** CAPI3REF: Allowed return values from sqlite3_txn_state()
6674 ** KEYWORDS: {transaction state}
6676 ** These constants define the current transaction state of a database file.
6677 ** ^The [sqlite3_txn_state(D,S)] interface returns one of these
6678 ** constants in order to describe the transaction state of schema S
6679 ** in [database connection] D.
6682 ** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt>
6683 ** <dd>The SQLITE_TXN_NONE state means that no transaction is currently
6686 ** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt>
6687 ** <dd>The SQLITE_TXN_READ state means that the database is currently
6688 ** in a read transaction. Content has been read from the database file
6689 ** but nothing in the database file has changed. The transaction state
6690 ** will advanced to SQLITE_TXN_WRITE if any changes occur and there are
6691 ** no other conflicting concurrent write transactions. The transaction
6692 ** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or
6695 ** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt>
6696 ** <dd>The SQLITE_TXN_WRITE state means that the database is currently
6697 ** in a write transaction. Content has been written to the database file
6698 ** but has not yet committed. The transaction state will change to
6699 ** to SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd>
6701 #define SQLITE_TXN_NONE 0
6702 #define SQLITE_TXN_READ 1
6703 #define SQLITE_TXN_WRITE 2
6706 ** CAPI3REF: Find the next prepared statement
6709 ** ^This interface returns a pointer to the next [prepared statement] after
6710 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
6711 ** then this interface returns a pointer to the first prepared statement
6712 ** associated with the database connection pDb. ^If no prepared statement
6713 ** satisfies the conditions of this routine, it returns NULL.
6715 ** The [database connection] pointer D in a call to
6716 ** [sqlite3_next_stmt(D,S)] must refer to an open database
6717 ** connection and in particular must not be a NULL pointer.
6719 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
6722 ** CAPI3REF: Commit And Rollback Notification Callbacks
6725 ** ^The sqlite3_commit_hook() interface registers a callback
6726 ** function to be invoked whenever a transaction is [COMMIT | committed].
6727 ** ^Any callback set by a previous call to sqlite3_commit_hook()
6728 ** for the same database connection is overridden.
6729 ** ^The sqlite3_rollback_hook() interface registers a callback
6730 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
6731 ** ^Any callback set by a previous call to sqlite3_rollback_hook()
6732 ** for the same database connection is overridden.
6733 ** ^The pArg argument is passed through to the callback.
6734 ** ^If the callback on a commit hook function returns non-zero,
6735 ** then the commit is converted into a rollback.
6737 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
6738 ** return the P argument from the previous call of the same function
6739 ** on the same [database connection] D, or NULL for
6740 ** the first call for each function on D.
6742 ** The commit and rollback hook callbacks are not reentrant.
6743 ** The callback implementation must not do anything that will modify
6744 ** the database connection that invoked the callback. Any actions
6745 ** to modify the database connection must be deferred until after the
6746 ** completion of the [sqlite3_step()] call that triggered the commit
6747 ** or rollback hook in the first place.
6748 ** Note that running any other SQL statements, including SELECT statements,
6749 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
6750 ** the database connections for the meaning of "modify" in this paragraph.
6752 ** ^Registering a NULL function disables the callback.
6754 ** ^When the commit hook callback routine returns zero, the [COMMIT]
6755 ** operation is allowed to continue normally. ^If the commit hook
6756 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
6757 ** ^The rollback hook is invoked on a rollback that results from a commit
6758 ** hook returning non-zero, just as it would be with any other rollback.
6760 ** ^For the purposes of this API, a transaction is said to have been
6761 ** rolled back if an explicit "ROLLBACK" statement is executed, or
6762 ** an error or constraint causes an implicit rollback to occur.
6763 ** ^The rollback callback is not invoked if a transaction is
6764 ** automatically rolled back because the database connection is closed.
6766 ** See also the [sqlite3_update_hook()] interface.
6768 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
6769 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
6772 ** CAPI3REF: Autovacuum Compaction Amount Callback
6775 ** ^The sqlite3_autovacuum_pages(D,C,P,X) interface registers a callback
6776 ** function C that is invoked prior to each autovacuum of the database
6777 ** file. ^The callback is passed a copy of the generic data pointer (P),
6778 ** the schema-name of the attached database that is being autovacuumed,
6779 ** the size of the database file in pages, the number of free pages,
6780 ** and the number of bytes per page, respectively. The callback should
6781 ** return the number of free pages that should be removed by the
6782 ** autovacuum. ^If the callback returns zero, then no autovacuum happens.
6783 ** ^If the value returned is greater than or equal to the number of
6784 ** free pages, then a complete autovacuum happens.
6786 ** <p>^If there are multiple ATTACH-ed database files that are being
6787 ** modified as part of a transaction commit, then the autovacuum pages
6788 ** callback is invoked separately for each file.
6790 ** <p><b>The callback is not reentrant.</b> The callback function should
6791 ** not attempt to invoke any other SQLite interface. If it does, bad
6792 ** things may happen, including segmentation faults and corrupt database
6793 ** files. The callback function should be a simple function that
6794 ** does some arithmetic on its input parameters and returns a result.
6796 ** ^The X parameter to sqlite3_autovacuum_pages(D,C,P,X) is an optional
6797 ** destructor for the P parameter. ^If X is not NULL, then X(P) is
6798 ** invoked whenever the database connection closes or when the callback
6799 ** is overwritten by another invocation of sqlite3_autovacuum_pages().
6801 ** <p>^There is only one autovacuum pages callback per database connection.
6802 ** ^Each call to the sqlite3_autovacuum_pages() interface overrides all
6803 ** previous invocations for that database connection. ^If the callback
6804 ** argument (C) to sqlite3_autovacuum_pages(D,C,P,X) is a NULL pointer,
6805 ** then the autovacuum steps callback is canceled. The return value
6806 ** from sqlite3_autovacuum_pages() is normally SQLITE_OK, but might
6807 ** be some other error code if something goes wrong. The current
6808 ** implementation will only return SQLITE_OK or SQLITE_MISUSE, but other
6809 ** return codes might be added in future releases.
6811 ** <p>If no autovacuum pages callback is specified (the usual case) or
6812 ** a NULL pointer is provided for the callback,
6813 ** then the default behavior is to vacuum all free pages. So, in other
6814 ** words, the default behavior is the same as if the callback function
6815 ** were something like this:
6817 ** <blockquote><pre>
6818 ** unsigned int demonstration_autovac_pages_callback(
6819 ** void *pClientData,
6820 ** const char *zSchema,
6821 ** unsigned int nDbPage,
6822 ** unsigned int nFreePage,
6823 ** unsigned int nBytePerPage
6825 ** return nFreePage;
6827 ** </pre></blockquote>
6829 SQLITE_API int sqlite3_autovacuum_pages(
6831 unsigned int(*)(void*,const char*,unsigned int,unsigned int,unsigned int),
6838 ** CAPI3REF: Data Change Notification Callbacks
6841 ** ^The sqlite3_update_hook() interface registers a callback function
6842 ** with the [database connection] identified by the first argument
6843 ** to be invoked whenever a row is updated, inserted or deleted in
6845 ** ^Any callback set by a previous call to this function
6846 ** for the same database connection is overridden.
6848 ** ^The second argument is a pointer to the function to invoke when a
6849 ** row is updated, inserted or deleted in a rowid table.
6850 ** ^The first argument to the callback is a copy of the third argument
6851 ** to sqlite3_update_hook().
6852 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
6853 ** or [SQLITE_UPDATE], depending on the operation that caused the callback
6855 ** ^The third and fourth arguments to the callback contain pointers to the
6856 ** database and table name containing the affected row.
6857 ** ^The final callback parameter is the [rowid] of the row.
6858 ** ^In the case of an update, this is the [rowid] after the update takes place.
6860 ** ^(The update hook is not invoked when internal system tables are
6861 ** modified (i.e. sqlite_sequence).)^
6862 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
6864 ** ^In the current implementation, the update hook
6865 ** is not invoked when conflicting rows are deleted because of an
6866 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
6867 ** invoked when rows are deleted using the [truncate optimization].
6868 ** The exceptions defined in this paragraph might change in a future
6869 ** release of SQLite.
6871 ** The update hook implementation must not do anything that will modify
6872 ** the database connection that invoked the update hook. Any actions
6873 ** to modify the database connection must be deferred until after the
6874 ** completion of the [sqlite3_step()] call that triggered the update hook.
6875 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
6876 ** database connections for the meaning of "modify" in this paragraph.
6878 ** ^The sqlite3_update_hook(D,C,P) function
6879 ** returns the P argument from the previous call
6880 ** on the same [database connection] D, or NULL for
6881 ** the first call on D.
6883 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],
6884 ** and [sqlite3_preupdate_hook()] interfaces.
6886 SQLITE_API void *sqlite3_update_hook(
6888 void(*)(void *,int ,char const *,char const *,sqlite3_int64),
6893 ** CAPI3REF: Enable Or Disable Shared Pager Cache
6895 ** ^(This routine enables or disables the sharing of the database cache
6896 ** and schema data structures between [database connection | connections]
6897 ** to the same database. Sharing is enabled if the argument is true
6898 ** and disabled if the argument is false.)^
6900 ** This interface is omitted if SQLite is compiled with
6901 ** [-DSQLITE_OMIT_SHARED_CACHE]. The [-DSQLITE_OMIT_SHARED_CACHE]
6902 ** compile-time option is recommended because the
6903 ** [use of shared cache mode is discouraged].
6905 ** ^Cache sharing is enabled and disabled for an entire process.
6906 ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]).
6907 ** In prior versions of SQLite,
6908 ** sharing was enabled or disabled for each thread separately.
6910 ** ^(The cache sharing mode set by this interface effects all subsequent
6911 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
6912 ** Existing database connections continue to use the sharing mode
6913 ** that was in effect at the time they were opened.)^
6915 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
6916 ** successfully. An [error code] is returned otherwise.)^
6918 ** ^Shared cache is disabled by default. It is recommended that it stay
6919 ** that way. In other words, do not use this routine. This interface
6920 ** continues to be provided for historical compatibility, but its use is
6921 ** discouraged. Any use of shared cache is discouraged. If shared cache
6922 ** must be used, it is recommended that shared cache only be enabled for
6923 ** individual database connections using the [sqlite3_open_v2()] interface
6924 ** with the [SQLITE_OPEN_SHAREDCACHE] flag.
6926 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
6927 ** and will always return SQLITE_MISUSE. On those systems,
6928 ** shared cache mode should be enabled per-database connection via
6929 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
6931 ** This interface is threadsafe on processors where writing a
6932 ** 32-bit integer is atomic.
6934 ** See Also: [SQLite Shared-Cache Mode]
6936 SQLITE_API int sqlite3_enable_shared_cache(int);
6939 ** CAPI3REF: Attempt To Free Heap Memory
6941 ** ^The sqlite3_release_memory() interface attempts to free N bytes
6942 ** of heap memory by deallocating non-essential memory allocations
6943 ** held by the database library. Memory used to cache database
6944 ** pages to improve performance is an example of non-essential memory.
6945 ** ^sqlite3_release_memory() returns the number of bytes actually freed,
6946 ** which might be more or less than the amount requested.
6947 ** ^The sqlite3_release_memory() routine is a no-op returning zero
6948 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
6950 ** See also: [sqlite3_db_release_memory()]
6952 SQLITE_API int sqlite3_release_memory(int);
6955 ** CAPI3REF: Free Memory Used By A Database Connection
6958 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
6959 ** memory as possible from database connection D. Unlike the
6960 ** [sqlite3_release_memory()] interface, this interface is in effect even
6961 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
6964 ** See also: [sqlite3_release_memory()]
6966 SQLITE_API int sqlite3_db_release_memory(sqlite3*);
6969 ** CAPI3REF: Impose A Limit On Heap Size
6971 ** These interfaces impose limits on the amount of heap memory that will be
6972 ** by all database connections within a single process.
6974 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
6975 ** soft limit on the amount of heap memory that may be allocated by SQLite.
6976 ** ^SQLite strives to keep heap memory utilization below the soft heap
6977 ** limit by reducing the number of pages held in the page cache
6978 ** as heap memory usages approaches the limit.
6979 ** ^The soft heap limit is "soft" because even though SQLite strives to stay
6980 ** below the limit, it will exceed the limit rather than generate
6981 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit
6982 ** is advisory only.
6984 ** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of
6985 ** N bytes on the amount of memory that will be allocated. ^The
6986 ** sqlite3_hard_heap_limit64(N) interface is similar to
6987 ** sqlite3_soft_heap_limit64(N) except that memory allocations will fail
6988 ** when the hard heap limit is reached.
6990 ** ^The return value from both sqlite3_soft_heap_limit64() and
6991 ** sqlite3_hard_heap_limit64() is the size of
6992 ** the heap limit prior to the call, or negative in the case of an
6993 ** error. ^If the argument N is negative
6994 ** then no change is made to the heap limit. Hence, the current
6995 ** size of heap limits can be determined by invoking
6996 ** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1).
6998 ** ^Setting the heap limits to zero disables the heap limiter mechanism.
7000 ** ^The soft heap limit may not be greater than the hard heap limit.
7001 ** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N)
7002 ** is invoked with a value of N that is greater than the hard heap limit,
7003 ** the soft heap limit is set to the value of the hard heap limit.
7004 ** ^The soft heap limit is automatically enabled whenever the hard heap
7005 ** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and
7006 ** the soft heap limit is outside the range of 1..N, then the soft heap
7007 ** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the
7008 ** hard heap limit is enabled makes the soft heap limit equal to the
7011 ** The memory allocation limits can also be adjusted using
7012 ** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit].
7014 ** ^(The heap limits are not enforced in the current implementation
7015 ** if one or more of following conditions are true:
7018 ** <li> The limit value is set to zero.
7019 ** <li> Memory accounting is disabled using a combination of the
7020 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
7021 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
7022 ** <li> An alternative page cache implementation is specified using
7023 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
7024 ** <li> The page cache allocates from its own memory pool supplied
7025 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
7029 ** The circumstances under which SQLite will enforce the heap limits may
7030 ** changes in future releases of SQLite.
7032 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
7033 SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N);
7036 ** CAPI3REF: Deprecated Soft Heap Limit Interface
7039 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
7040 ** interface. This routine is provided for historical compatibility
7041 ** only. All new applications should use the
7042 ** [sqlite3_soft_heap_limit64()] interface rather than this one.
7044 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
7048 ** CAPI3REF: Extract Metadata About A Column Of A Table
7051 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
7052 ** information about column C of table T in database D
7053 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata()
7054 ** interface returns SQLITE_OK and fills in the non-NULL pointers in
7055 ** the final five arguments with appropriate values if the specified
7056 ** column exists. ^The sqlite3_table_column_metadata() interface returns
7057 ** SQLITE_ERROR if the specified column does not exist.
7058 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a
7059 ** NULL pointer, then this routine simply checks for the existence of the
7060 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
7061 ** does not. If the table name parameter T in a call to
7062 ** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is
7063 ** undefined behavior.
7065 ** ^The column is identified by the second, third and fourth parameters to
7066 ** this function. ^(The second parameter is either the name of the database
7067 ** (i.e. "main", "temp", or an attached database) containing the specified
7068 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched
7069 ** for the table using the same algorithm used by the database engine to
7070 ** resolve unqualified table references.
7072 ** ^The third and fourth parameters to this function are the table and column
7073 ** name of the desired column, respectively.
7075 ** ^Metadata is returned by writing to the memory locations passed as the 5th
7076 ** and subsequent parameters to this function. ^Any of these arguments may be
7077 ** NULL, in which case the corresponding element of metadata is omitted.
7080 ** <table border="1">
7081 ** <tr><th> Parameter <th> Output<br>Type <th> Description
7083 ** <tr><td> 5th <td> const char* <td> Data type
7084 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence
7085 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
7086 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
7087 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
7091 ** ^The memory pointed to by the character pointers returned for the
7092 ** declaration type and collation sequence is valid until the next
7093 ** call to any SQLite API function.
7095 ** ^If the specified table is actually a view, an [error code] is returned.
7097 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table
7098 ** is not a [WITHOUT ROWID] table and an
7099 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
7100 ** parameters are set for the explicitly declared column. ^(If there is no
7101 ** [INTEGER PRIMARY KEY] column, then the outputs
7102 ** for the [rowid] are set as follows:
7105 ** data type: "INTEGER"
7106 ** collation sequence: "BINARY"
7109 ** auto increment: 0
7112 ** ^This function causes all database schemas to be read from disk and
7113 ** parsed, if that has not already been done, and returns an error if
7114 ** any errors are encountered while loading the schema.
7116 SQLITE_API int sqlite3_table_column_metadata(
7117 sqlite3 *db, /* Connection handle */
7118 const char *zDbName, /* Database name or NULL */
7119 const char *zTableName, /* Table name */
7120 const char *zColumnName, /* Column name */
7121 char const **pzDataType, /* OUTPUT: Declared data type */
7122 char const **pzCollSeq, /* OUTPUT: Collation sequence name */
7123 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
7124 int *pPrimaryKey, /* OUTPUT: True if column part of PK */
7125 int *pAutoinc /* OUTPUT: True if column is auto-increment */
7129 ** CAPI3REF: Load An Extension
7132 ** ^This interface loads an SQLite extension library from the named file.
7134 ** ^The sqlite3_load_extension() interface attempts to load an
7135 ** [SQLite extension] library contained in the file zFile. If
7136 ** the file cannot be loaded directly, attempts are made to load
7137 ** with various operating-system specific extensions added.
7138 ** So for example, if "samplelib" cannot be loaded, then names like
7139 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
7142 ** ^The entry point is zProc.
7143 ** ^(zProc may be 0, in which case SQLite will try to come up with an
7144 ** entry point name on its own. It first tries "sqlite3_extension_init".
7145 ** If that does not work, it constructs a name "sqlite3_X_init" where the
7146 ** X is consists of the lower-case equivalent of all ASCII alphabetic
7147 ** characters in the filename from the last "/" to the first following
7148 ** "." and omitting any initial "lib".)^
7149 ** ^The sqlite3_load_extension() interface returns
7150 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
7151 ** ^If an error occurs and pzErrMsg is not 0, then the
7152 ** [sqlite3_load_extension()] interface shall attempt to
7153 ** fill *pzErrMsg with error message text stored in memory
7154 ** obtained from [sqlite3_malloc()]. The calling function
7155 ** should free this memory by calling [sqlite3_free()].
7157 ** ^Extension loading must be enabled using
7158 ** [sqlite3_enable_load_extension()] or
7159 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL)
7160 ** prior to calling this API,
7161 ** otherwise an error will be returned.
7163 ** <b>Security warning:</b> It is recommended that the
7164 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this
7165 ** interface. The use of the [sqlite3_enable_load_extension()] interface
7166 ** should be avoided. This will keep the SQL function [load_extension()]
7167 ** disabled and prevent SQL injections from giving attackers
7168 ** access to extension loading capabilities.
7170 ** See also the [load_extension() SQL function].
7172 SQLITE_API int sqlite3_load_extension(
7173 sqlite3 *db, /* Load the extension into this database connection */
7174 const char *zFile, /* Name of the shared library containing extension */
7175 const char *zProc, /* Entry point. Derived from zFile if 0 */
7176 char **pzErrMsg /* Put error message here if not 0 */
7180 ** CAPI3REF: Enable Or Disable Extension Loading
7183 ** ^So as not to open security holes in older applications that are
7184 ** unprepared to deal with [extension loading], and as a means of disabling
7185 ** [extension loading] while evaluating user-entered SQL, the following API
7186 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
7188 ** ^Extension loading is off by default.
7189 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1
7190 ** to turn extension loading on and call it with onoff==0 to turn
7191 ** it back off again.
7193 ** ^This interface enables or disables both the C-API
7194 ** [sqlite3_load_extension()] and the SQL function [load_extension()].
7195 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..)
7196 ** to enable or disable only the C-API.)^
7198 ** <b>Security warning:</b> It is recommended that extension loading
7199 ** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method
7200 ** rather than this interface, so the [load_extension()] SQL function
7201 ** remains disabled. This will prevent SQL injections from giving attackers
7202 ** access to extension loading capabilities.
7204 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
7207 ** CAPI3REF: Automatically Load Statically Linked Extensions
7209 ** ^This interface causes the xEntryPoint() function to be invoked for
7210 ** each new [database connection] that is created. The idea here is that
7211 ** xEntryPoint() is the entry point for a statically linked [SQLite extension]
7212 ** that is to be automatically loaded into all new database connections.
7214 ** ^(Even though the function prototype shows that xEntryPoint() takes
7215 ** no arguments and returns void, SQLite invokes xEntryPoint() with three
7216 ** arguments and expects an integer result as if the signature of the
7217 ** entry point where as follows:
7219 ** <blockquote><pre>
7220 ** int xEntryPoint(
7221 ** sqlite3 *db,
7222 ** const char **pzErrMsg,
7223 ** const struct sqlite3_api_routines *pThunk
7225 ** </pre></blockquote>)^
7227 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
7228 ** point to an appropriate error message (obtained from [sqlite3_mprintf()])
7229 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
7230 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke
7231 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
7232 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
7233 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
7235 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
7236 ** on the list of automatic extensions is a harmless no-op. ^No entry point
7237 ** will be called more than once for each database connection that is opened.
7239 ** See also: [sqlite3_reset_auto_extension()]
7240 ** and [sqlite3_cancel_auto_extension()]
7242 SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void));
7245 ** CAPI3REF: Cancel Automatic Extension Loading
7247 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
7248 ** initialization routine X that was registered using a prior call to
7249 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)]
7250 ** routine returns 1 if initialization routine X was successfully
7251 ** unregistered and it returns 0 if X was not on the list of initialization
7254 SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void));
7257 ** CAPI3REF: Reset Automatic Extension Loading
7259 ** ^This interface disables all automatic extensions previously
7260 ** registered using [sqlite3_auto_extension()].
7262 SQLITE_API void sqlite3_reset_auto_extension(void);
7265 ** Structures used by the virtual table interface
7267 typedef struct sqlite3_vtab sqlite3_vtab;
7268 typedef struct sqlite3_index_info sqlite3_index_info;
7269 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
7270 typedef struct sqlite3_module sqlite3_module;
7273 ** CAPI3REF: Virtual Table Object
7274 ** KEYWORDS: sqlite3_module {virtual table module}
7276 ** This structure, sometimes called a "virtual table module",
7277 ** defines the implementation of a [virtual table].
7278 ** This structure consists mostly of methods for the module.
7280 ** ^A virtual table module is created by filling in a persistent
7281 ** instance of this structure and passing a pointer to that instance
7282 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
7283 ** ^The registration remains valid until it is replaced by a different
7284 ** module or until the [database connection] closes. The content
7285 ** of this structure must not change while it is registered with
7286 ** any database connection.
7288 struct sqlite3_module {
7290 int (*xCreate)(sqlite3*, void *pAux,
7291 int argc, const char *const*argv,
7292 sqlite3_vtab **ppVTab, char**);
7293 int (*xConnect)(sqlite3*, void *pAux,
7294 int argc, const char *const*argv,
7295 sqlite3_vtab **ppVTab, char**);
7296 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
7297 int (*xDisconnect)(sqlite3_vtab *pVTab);
7298 int (*xDestroy)(sqlite3_vtab *pVTab);
7299 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
7300 int (*xClose)(sqlite3_vtab_cursor*);
7301 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
7302 int argc, sqlite3_value **argv);
7303 int (*xNext)(sqlite3_vtab_cursor*);
7304 int (*xEof)(sqlite3_vtab_cursor*);
7305 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
7306 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
7307 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
7308 int (*xBegin)(sqlite3_vtab *pVTab);
7309 int (*xSync)(sqlite3_vtab *pVTab);
7310 int (*xCommit)(sqlite3_vtab *pVTab);
7311 int (*xRollback)(sqlite3_vtab *pVTab);
7312 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
7313 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
7315 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
7316 /* The methods above are in version 1 of the sqlite_module object. Those
7317 ** below are for version 2 and greater. */
7318 int (*xSavepoint)(sqlite3_vtab *pVTab, int);
7319 int (*xRelease)(sqlite3_vtab *pVTab, int);
7320 int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
7321 /* The methods above are in versions 1 and 2 of the sqlite_module object.
7322 ** Those below are for version 3 and greater. */
7323 int (*xShadowName)(const char*);
7324 /* The methods above are in versions 1 through 3 of the sqlite_module object.
7325 ** Those below are for version 4 and greater. */
7326 int (*xIntegrity)(sqlite3_vtab *pVTab, const char *zSchema,
7327 const char *zTabName, int mFlags, char **pzErr);
7331 ** CAPI3REF: Virtual Table Indexing Information
7332 ** KEYWORDS: sqlite3_index_info
7334 ** The sqlite3_index_info structure and its substructures is used as part
7335 ** of the [virtual table] interface to
7336 ** pass information into and receive the reply from the [xBestIndex]
7337 ** method of a [virtual table module]. The fields under **Inputs** are the
7338 ** inputs to xBestIndex and are read-only. xBestIndex inserts its
7339 ** results into the **Outputs** fields.
7341 ** ^(The aConstraint[] array records WHERE clause constraints of the form:
7343 ** <blockquote>column OP expr</blockquote>
7345 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is
7346 ** stored in aConstraint[].op using one of the
7347 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
7348 ** ^(The index of the column is stored in
7349 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
7350 ** expr on the right-hand side can be evaluated (and thus the constraint
7351 ** is usable) and false if it cannot.)^
7353 ** ^The optimizer automatically inverts terms of the form "expr OP column"
7354 ** and makes other simplifications to the WHERE clause in an attempt to
7355 ** get as many WHERE clause terms into the form shown above as possible.
7356 ** ^The aConstraint[] array only reports WHERE clause terms that are
7357 ** relevant to the particular virtual table being queried.
7359 ** ^Information about the ORDER BY clause is stored in aOrderBy[].
7360 ** ^Each term of aOrderBy records a column of the ORDER BY clause.
7362 ** The colUsed field indicates which columns of the virtual table may be
7363 ** required by the current scan. Virtual table columns are numbered from
7364 ** zero in the order in which they appear within the CREATE TABLE statement
7365 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
7366 ** the corresponding bit is set within the colUsed mask if the column may be
7367 ** required by SQLite. If the table has at least 64 columns and any column
7368 ** to the right of the first 63 is required, then bit 63 of colUsed is also
7369 ** set. In other words, column iCol may be required if the expression
7370 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to
7373 ** The [xBestIndex] method must fill aConstraintUsage[] with information
7374 ** about what parameters to pass to xFilter. ^If argvIndex>0 then
7375 ** the right-hand side of the corresponding aConstraint[] is evaluated
7376 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
7377 ** is true, then the constraint is assumed to be fully handled by the
7378 ** virtual table and might not be checked again by the byte code.)^ ^(The
7379 ** aConstraintUsage[].omit flag is an optimization hint. When the omit flag
7380 ** is left in its default setting of false, the constraint will always be
7381 ** checked separately in byte code. If the omit flag is change to true, then
7382 ** the constraint may or may not be checked in byte code. In other words,
7383 ** when the omit flag is true there is no guarantee that the constraint will
7384 ** not be checked again using byte code.)^
7386 ** ^The idxNum and idxStr values are recorded and passed into the
7387 ** [xFilter] method.
7388 ** ^[sqlite3_free()] is used to free idxStr if and only if
7389 ** needToFreeIdxStr is true.
7391 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
7392 ** the correct order to satisfy the ORDER BY clause so that no separate
7393 ** sorting step is required.
7395 ** ^The estimatedCost value is an estimate of the cost of a particular
7396 ** strategy. A cost of N indicates that the cost of the strategy is similar
7397 ** to a linear scan of an SQLite table with N rows. A cost of log(N)
7398 ** indicates that the expense of the operation is similar to that of a
7399 ** binary search on a unique indexed field of an SQLite table with N rows.
7401 ** ^The estimatedRows value is an estimate of the number of rows that
7402 ** will be returned by the strategy.
7404 ** The xBestIndex method may optionally populate the idxFlags field with a
7405 ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag -
7406 ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite
7407 ** assumes that the strategy may visit at most one row.
7409 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
7410 ** SQLite also assumes that if a call to the xUpdate() method is made as
7411 ** part of the same statement to delete or update a virtual table row and the
7412 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
7413 ** any database changes. In other words, if the xUpdate() returns
7414 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were
7415 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
7416 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
7417 ** the xUpdate method are automatically rolled back by SQLite.
7419 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
7420 ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]).
7421 ** If a virtual table extension is
7422 ** used with an SQLite version earlier than 3.8.2, the results of attempting
7423 ** to read or write the estimatedRows field are undefined (but are likely
7424 ** to include crashing the application). The estimatedRows field should
7425 ** therefore only be used if [sqlite3_libversion_number()] returns a
7426 ** value greater than or equal to 3008002. Similarly, the idxFlags field
7427 ** was added for [version 3.9.0] ([dateof:3.9.0]).
7428 ** It may therefore only be used if
7429 ** sqlite3_libversion_number() returns a value greater than or equal to
7432 struct sqlite3_index_info {
7434 int nConstraint; /* Number of entries in aConstraint */
7435 struct sqlite3_index_constraint {
7436 int iColumn; /* Column constrained. -1 for ROWID */
7437 unsigned char op; /* Constraint operator */
7438 unsigned char usable; /* True if this constraint is usable */
7439 int iTermOffset; /* Used internally - xBestIndex should ignore */
7440 } *aConstraint; /* Table of WHERE clause constraints */
7441 int nOrderBy; /* Number of terms in the ORDER BY clause */
7442 struct sqlite3_index_orderby {
7443 int iColumn; /* Column number */
7444 unsigned char desc; /* True for DESC. False for ASC. */
7445 } *aOrderBy; /* The ORDER BY clause */
7447 struct sqlite3_index_constraint_usage {
7448 int argvIndex; /* if >0, constraint is part of argv to xFilter */
7449 unsigned char omit; /* Do not code a test for this constraint */
7450 } *aConstraintUsage;
7451 int idxNum; /* Number used to identify the index */
7452 char *idxStr; /* String, possibly obtained from sqlite3_malloc */
7453 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
7454 int orderByConsumed; /* True if output is already ordered */
7455 double estimatedCost; /* Estimated cost of using this index */
7456 /* Fields below are only available in SQLite 3.8.2 and later */
7457 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */
7458 /* Fields below are only available in SQLite 3.9.0 and later */
7459 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */
7460 /* Fields below are only available in SQLite 3.10.0 and later */
7461 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */
7465 ** CAPI3REF: Virtual Table Scan Flags
7467 ** Virtual table implementations are allowed to set the
7468 ** [sqlite3_index_info].idxFlags field to some combination of
7471 #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */
7474 ** CAPI3REF: Virtual Table Constraint Operator Codes
7476 ** These macros define the allowed values for the
7477 ** [sqlite3_index_info].aConstraint[].op field. Each value represents
7478 ** an operator that is part of a constraint term in the WHERE clause of
7479 ** a query that uses a [virtual table].
7481 ** ^The left-hand operand of the operator is given by the corresponding
7482 ** aConstraint[].iColumn field. ^An iColumn of -1 indicates the left-hand
7483 ** operand is the rowid.
7484 ** The SQLITE_INDEX_CONSTRAINT_LIMIT and SQLITE_INDEX_CONSTRAINT_OFFSET
7485 ** operators have no left-hand operand, and so for those operators the
7486 ** corresponding aConstraint[].iColumn is meaningless and should not be
7489 ** All operator values from SQLITE_INDEX_CONSTRAINT_FUNCTION through
7490 ** value 255 are reserved to represent functions that are overloaded
7491 ** by the [xFindFunction|xFindFunction method] of the virtual table
7494 ** The right-hand operands for each constraint might be accessible using
7495 ** the [sqlite3_vtab_rhs_value()] interface. Usually the right-hand
7496 ** operand is only available if it appears as a single constant literal
7497 ** in the input SQL. If the right-hand operand is another column or an
7498 ** expression (even a constant expression) or a parameter, then the
7499 ** sqlite3_vtab_rhs_value() probably will not be able to extract it.
7500 ** ^The SQLITE_INDEX_CONSTRAINT_ISNULL and
7501 ** SQLITE_INDEX_CONSTRAINT_ISNOTNULL operators have no right-hand operand
7502 ** and hence calls to sqlite3_vtab_rhs_value() for those operators will
7503 ** always return SQLITE_NOTFOUND.
7505 ** The collating sequence to be used for comparison can be found using
7506 ** the [sqlite3_vtab_collation()] interface. For most real-world virtual
7507 ** tables, the collating sequence of constraints does not matter (for example
7508 ** because the constraints are numeric) and so the sqlite3_vtab_collation()
7509 ** interface is not commonly needed.
7511 #define SQLITE_INDEX_CONSTRAINT_EQ 2
7512 #define SQLITE_INDEX_CONSTRAINT_GT 4
7513 #define SQLITE_INDEX_CONSTRAINT_LE 8
7514 #define SQLITE_INDEX_CONSTRAINT_LT 16
7515 #define SQLITE_INDEX_CONSTRAINT_GE 32
7516 #define SQLITE_INDEX_CONSTRAINT_MATCH 64
7517 #define SQLITE_INDEX_CONSTRAINT_LIKE 65
7518 #define SQLITE_INDEX_CONSTRAINT_GLOB 66
7519 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67
7520 #define SQLITE_INDEX_CONSTRAINT_NE 68
7521 #define SQLITE_INDEX_CONSTRAINT_ISNOT 69
7522 #define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70
7523 #define SQLITE_INDEX_CONSTRAINT_ISNULL 71
7524 #define SQLITE_INDEX_CONSTRAINT_IS 72
7525 #define SQLITE_INDEX_CONSTRAINT_LIMIT 73
7526 #define SQLITE_INDEX_CONSTRAINT_OFFSET 74
7527 #define SQLITE_INDEX_CONSTRAINT_FUNCTION 150
7530 ** CAPI3REF: Register A Virtual Table Implementation
7533 ** ^These routines are used to register a new [virtual table module] name.
7534 ** ^Module names must be registered before
7535 ** creating a new [virtual table] using the module and before using a
7536 ** preexisting [virtual table] for the module.
7538 ** ^The module name is registered on the [database connection] specified
7539 ** by the first parameter. ^The name of the module is given by the
7540 ** second parameter. ^The third parameter is a pointer to
7541 ** the implementation of the [virtual table module]. ^The fourth
7542 ** parameter is an arbitrary client data pointer that is passed through
7543 ** into the [xCreate] and [xConnect] methods of the virtual table module
7544 ** when a new virtual table is be being created or reinitialized.
7546 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which
7547 ** is a pointer to a destructor for the pClientData. ^SQLite will
7548 ** invoke the destructor function (if it is not NULL) when SQLite
7549 ** no longer needs the pClientData pointer. ^The destructor will also
7550 ** be invoked if the call to sqlite3_create_module_v2() fails.
7551 ** ^The sqlite3_create_module()
7552 ** interface is equivalent to sqlite3_create_module_v2() with a NULL
7555 ** ^If the third parameter (the pointer to the sqlite3_module object) is
7556 ** NULL then no new module is created and any existing modules with the
7557 ** same name are dropped.
7559 ** See also: [sqlite3_drop_modules()]
7561 SQLITE_API int sqlite3_create_module(
7562 sqlite3 *db, /* SQLite connection to register module with */
7563 const char *zName, /* Name of the module */
7564 const sqlite3_module *p, /* Methods for the module */
7565 void *pClientData /* Client data for xCreate/xConnect */
7567 SQLITE_API int sqlite3_create_module_v2(
7568 sqlite3 *db, /* SQLite connection to register module with */
7569 const char *zName, /* Name of the module */
7570 const sqlite3_module *p, /* Methods for the module */
7571 void *pClientData, /* Client data for xCreate/xConnect */
7572 void(*xDestroy)(void*) /* Module destructor function */
7576 ** CAPI3REF: Remove Unnecessary Virtual Table Implementations
7579 ** ^The sqlite3_drop_modules(D,L) interface removes all virtual
7580 ** table modules from database connection D except those named on list L.
7581 ** The L parameter must be either NULL or a pointer to an array of pointers
7582 ** to strings where the array is terminated by a single NULL pointer.
7583 ** ^If the L parameter is NULL, then all virtual table modules are removed.
7585 ** See also: [sqlite3_create_module()]
7587 SQLITE_API int sqlite3_drop_modules(
7588 sqlite3 *db, /* Remove modules from this connection */
7589 const char **azKeep /* Except, do not remove the ones named here */
7593 ** CAPI3REF: Virtual Table Instance Object
7594 ** KEYWORDS: sqlite3_vtab
7596 ** Every [virtual table module] implementation uses a subclass
7597 ** of this object to describe a particular instance
7598 ** of the [virtual table]. Each subclass will
7599 ** be tailored to the specific needs of the module implementation.
7600 ** The purpose of this superclass is to define certain fields that are
7601 ** common to all module implementations.
7603 ** ^Virtual tables methods can set an error message by assigning a
7604 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
7605 ** take care that any prior string is freed by a call to [sqlite3_free()]
7606 ** prior to assigning a new string to zErrMsg. ^After the error message
7607 ** is delivered up to the client application, the string will be automatically
7608 ** freed by sqlite3_free() and the zErrMsg field will be zeroed.
7610 struct sqlite3_vtab {
7611 const sqlite3_module *pModule; /* The module for this virtual table */
7612 int nRef; /* Number of open cursors */
7613 char *zErrMsg; /* Error message from sqlite3_mprintf() */
7614 /* Virtual table implementations will typically add additional fields */
7618 ** CAPI3REF: Virtual Table Cursor Object
7619 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
7621 ** Every [virtual table module] implementation uses a subclass of the
7622 ** following structure to describe cursors that point into the
7623 ** [virtual table] and are used
7624 ** to loop through the virtual table. Cursors are created using the
7625 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
7626 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used
7627 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
7628 ** of the module. Each module implementation will define
7629 ** the content of a cursor structure to suit its own needs.
7631 ** This superclass exists in order to define fields of the cursor that
7632 ** are common to all implementations.
7634 struct sqlite3_vtab_cursor {
7635 sqlite3_vtab *pVtab; /* Virtual table of this cursor */
7636 /* Virtual table implementations will typically add additional fields */
7640 ** CAPI3REF: Declare The Schema Of A Virtual Table
7642 ** ^The [xCreate] and [xConnect] methods of a
7643 ** [virtual table module] call this interface
7644 ** to declare the format (the names and datatypes of the columns) of
7645 ** the virtual tables they implement.
7647 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
7650 ** CAPI3REF: Overload A Function For A Virtual Table
7653 ** ^(Virtual tables can provide alternative implementations of functions
7654 ** using the [xFindFunction] method of the [virtual table module].
7655 ** But global versions of those functions
7656 ** must exist in order to be overloaded.)^
7658 ** ^(This API makes sure a global version of a function with a particular
7659 ** name and number of parameters exists. If no such function exists
7660 ** before this API is called, a new function is created.)^ ^The implementation
7661 ** of the new function always causes an exception to be thrown. So
7662 ** the new function is not good for anything by itself. Its only
7663 ** purpose is to be a placeholder function that can be overloaded
7664 ** by a [virtual table].
7666 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
7669 ** CAPI3REF: A Handle To An Open BLOB
7670 ** KEYWORDS: {BLOB handle} {BLOB handles}
7672 ** An instance of this object represents an open BLOB on which
7673 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
7674 ** ^Objects of this type are created by [sqlite3_blob_open()]
7675 ** and destroyed by [sqlite3_blob_close()].
7676 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
7677 ** can be used to read or write small subsections of the BLOB.
7678 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
7680 typedef struct sqlite3_blob sqlite3_blob;
7683 ** CAPI3REF: Open A BLOB For Incremental I/O
7685 ** CONSTRUCTOR: sqlite3_blob
7687 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
7688 ** in row iRow, column zColumn, table zTable in database zDb;
7689 ** in other words, the same BLOB that would be selected by:
7692 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
7695 ** ^(Parameter zDb is not the filename that contains the database, but
7696 ** rather the symbolic name of the database. For attached databases, this is
7697 ** the name that appears after the AS keyword in the [ATTACH] statement.
7698 ** For the main database file, the database name is "main". For TEMP
7699 ** tables, the database name is "temp".)^
7701 ** ^If the flags parameter is non-zero, then the BLOB is opened for read
7702 ** and write access. ^If the flags parameter is zero, the BLOB is opened for
7703 ** read-only access.
7705 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
7706 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error
7707 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
7708 ** the API is not misused, it is always safe to call [sqlite3_blob_close()]
7709 ** on *ppBlob after this function it returns.
7711 ** This function fails with SQLITE_ERROR if any of the following are true:
7713 ** <li> ^(Database zDb does not exist)^,
7714 ** <li> ^(Table zTable does not exist within database zDb)^,
7715 ** <li> ^(Table zTable is a WITHOUT ROWID table)^,
7716 ** <li> ^(Column zColumn does not exist)^,
7717 ** <li> ^(Row iRow is not present in the table)^,
7718 ** <li> ^(The specified column of row iRow contains a value that is not
7719 ** a TEXT or BLOB value)^,
7720 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE
7721 ** constraint and the blob is being opened for read/write access)^,
7722 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled,
7723 ** column zColumn is part of a [child key] definition and the blob is
7724 ** being opened for read/write access)^.
7727 ** ^Unless it returns SQLITE_MISUSE, this function sets the
7728 ** [database connection] error code and message accessible via
7729 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
7731 ** A BLOB referenced by sqlite3_blob_open() may be read using the
7732 ** [sqlite3_blob_read()] interface and modified by using
7733 ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a
7734 ** different row of the same table using the [sqlite3_blob_reopen()]
7735 ** interface. However, the column, table, or database of a [BLOB handle]
7736 ** cannot be changed after the [BLOB handle] is opened.
7738 ** ^(If the row that a BLOB handle points to is modified by an
7739 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
7740 ** then the BLOB handle is marked as "expired".
7741 ** This is true if any column of the row is changed, even a column
7742 ** other than the one the BLOB handle is open on.)^
7743 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
7744 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
7745 ** ^(Changes written into a BLOB prior to the BLOB expiring are not
7746 ** rolled back by the expiration of the BLOB. Such changes will eventually
7747 ** commit if the transaction continues to completion.)^
7749 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
7750 ** the opened blob. ^The size of a blob may not be changed by this
7751 ** interface. Use the [UPDATE] SQL command to change the size of a
7754 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
7755 ** and the built-in [zeroblob] SQL function may be used to create a
7756 ** zero-filled blob to read or write using the incremental-blob interface.
7758 ** To avoid a resource leak, every open [BLOB handle] should eventually
7759 ** be released by a call to [sqlite3_blob_close()].
7761 ** See also: [sqlite3_blob_close()],
7762 ** [sqlite3_blob_reopen()], [sqlite3_blob_read()],
7763 ** [sqlite3_blob_bytes()], [sqlite3_blob_write()].
7765 SQLITE_API int sqlite3_blob_open(
7769 const char *zColumn,
7772 sqlite3_blob **ppBlob
7776 ** CAPI3REF: Move a BLOB Handle to a New Row
7777 ** METHOD: sqlite3_blob
7779 ** ^This function is used to move an existing [BLOB handle] so that it points
7780 ** to a different row of the same database table. ^The new row is identified
7781 ** by the rowid value passed as the second argument. Only the row can be
7782 ** changed. ^The database, table and column on which the blob handle is open
7783 ** remain the same. Moving an existing [BLOB handle] to a new row is
7784 ** faster than closing the existing handle and opening a new one.
7786 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
7787 ** it must exist and there must be either a blob or text value stored in
7788 ** the nominated column.)^ ^If the new row is not present in the table, or if
7789 ** it does not contain a blob or text value, or if another error occurs, an
7790 ** SQLite error code is returned and the blob handle is considered aborted.
7791 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
7792 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
7793 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
7794 ** always returns zero.
7796 ** ^This function sets the database handle error code and message.
7798 SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
7801 ** CAPI3REF: Close A BLOB Handle
7802 ** DESTRUCTOR: sqlite3_blob
7804 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
7805 ** unconditionally. Even if this routine returns an error code, the
7806 ** handle is still closed.)^
7808 ** ^If the blob handle being closed was opened for read-write access, and if
7809 ** the database is in auto-commit mode and there are no other open read-write
7810 ** blob handles or active write statements, the current transaction is
7811 ** committed. ^If an error occurs while committing the transaction, an error
7812 ** code is returned and the transaction rolled back.
7814 ** Calling this function with an argument that is not a NULL pointer or an
7815 ** open blob handle results in undefined behavior. ^Calling this routine
7816 ** with a null pointer (such as would be returned by a failed call to
7817 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
7818 ** is passed a valid open blob handle, the values returned by the
7819 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
7821 SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
7824 ** CAPI3REF: Return The Size Of An Open BLOB
7825 ** METHOD: sqlite3_blob
7827 ** ^Returns the size in bytes of the BLOB accessible via the
7828 ** successfully opened [BLOB handle] in its only argument. ^The
7829 ** incremental blob I/O routines can only read or overwriting existing
7830 ** blob content; they cannot change the size of a blob.
7832 ** This routine only works on a [BLOB handle] which has been created
7833 ** by a prior successful call to [sqlite3_blob_open()] and which has not
7834 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7835 ** to this routine results in undefined and probably undesirable behavior.
7837 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
7840 ** CAPI3REF: Read Data From A BLOB Incrementally
7841 ** METHOD: sqlite3_blob
7843 ** ^(This function is used to read data from an open [BLOB handle] into a
7844 ** caller-supplied buffer. N bytes of data are copied into buffer Z
7845 ** from the open BLOB, starting at offset iOffset.)^
7847 ** ^If offset iOffset is less than N bytes from the end of the BLOB,
7848 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
7849 ** less than zero, [SQLITE_ERROR] is returned and no data is read.
7850 ** ^The size of the blob (and hence the maximum value of N+iOffset)
7851 ** can be determined using the [sqlite3_blob_bytes()] interface.
7853 ** ^An attempt to read from an expired [BLOB handle] fails with an
7854 ** error code of [SQLITE_ABORT].
7856 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
7857 ** Otherwise, an [error code] or an [extended error code] is returned.)^
7859 ** This routine only works on a [BLOB handle] which has been created
7860 ** by a prior successful call to [sqlite3_blob_open()] and which has not
7861 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7862 ** to this routine results in undefined and probably undesirable behavior.
7864 ** See also: [sqlite3_blob_write()].
7866 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
7869 ** CAPI3REF: Write Data Into A BLOB Incrementally
7870 ** METHOD: sqlite3_blob
7872 ** ^(This function is used to write data into an open [BLOB handle] from a
7873 ** caller-supplied buffer. N bytes of data are copied from the buffer Z
7874 ** into the open BLOB, starting at offset iOffset.)^
7876 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
7877 ** Otherwise, an [error code] or an [extended error code] is returned.)^
7878 ** ^Unless SQLITE_MISUSE is returned, this function sets the
7879 ** [database connection] error code and message accessible via
7880 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
7882 ** ^If the [BLOB handle] passed as the first argument was not opened for
7883 ** writing (the flags parameter to [sqlite3_blob_open()] was zero),
7884 ** this function returns [SQLITE_READONLY].
7886 ** This function may only modify the contents of the BLOB; it is
7887 ** not possible to increase the size of a BLOB using this API.
7888 ** ^If offset iOffset is less than N bytes from the end of the BLOB,
7889 ** [SQLITE_ERROR] is returned and no data is written. The size of the
7890 ** BLOB (and hence the maximum value of N+iOffset) can be determined
7891 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less
7892 ** than zero [SQLITE_ERROR] is returned and no data is written.
7894 ** ^An attempt to write to an expired [BLOB handle] fails with an
7895 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
7896 ** before the [BLOB handle] expired are not rolled back by the
7897 ** expiration of the handle, though of course those changes might
7898 ** have been overwritten by the statement that expired the BLOB handle
7899 ** or by other independent statements.
7901 ** This routine only works on a [BLOB handle] which has been created
7902 ** by a prior successful call to [sqlite3_blob_open()] and which has not
7903 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7904 ** to this routine results in undefined and probably undesirable behavior.
7906 ** See also: [sqlite3_blob_read()].
7908 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
7911 ** CAPI3REF: Virtual File System Objects
7913 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object
7914 ** that SQLite uses to interact
7915 ** with the underlying operating system. Most SQLite builds come with a
7916 ** single default VFS that is appropriate for the host computer.
7917 ** New VFSes can be registered and existing VFSes can be unregistered.
7918 ** The following interfaces are provided.
7920 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
7921 ** ^Names are case sensitive.
7922 ** ^Names are zero-terminated UTF-8 strings.
7923 ** ^If there is no match, a NULL pointer is returned.
7924 ** ^If zVfsName is NULL then the default VFS is returned.
7926 ** ^New VFSes are registered with sqlite3_vfs_register().
7927 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
7928 ** ^The same VFS can be registered multiple times without injury.
7929 ** ^To make an existing VFS into the default VFS, register it again
7930 ** with the makeDflt flag set. If two different VFSes with the
7931 ** same name are registered, the behavior is undefined. If a
7932 ** VFS is registered with a name that is NULL or an empty string,
7933 ** then the behavior is undefined.
7935 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
7936 ** ^(If the default VFS is unregistered, another VFS is chosen as
7937 ** the default. The choice for the new VFS is arbitrary.)^
7939 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
7940 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
7941 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
7944 ** CAPI3REF: Mutexes
7946 ** The SQLite core uses these routines for thread
7947 ** synchronization. Though they are intended for internal
7948 ** use by SQLite, code that links against SQLite is
7949 ** permitted to use any of these routines.
7951 ** The SQLite source code contains multiple implementations
7952 ** of these mutex routines. An appropriate implementation
7953 ** is selected automatically at compile-time. The following
7954 ** implementations are available in the SQLite core:
7957 ** <li> SQLITE_MUTEX_PTHREADS
7958 ** <li> SQLITE_MUTEX_W32
7959 ** <li> SQLITE_MUTEX_NOOP
7962 ** The SQLITE_MUTEX_NOOP implementation is a set of routines
7963 ** that does no real locking and is appropriate for use in
7964 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and
7965 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
7968 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
7969 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
7970 ** implementation is included with the library. In this case the
7971 ** application must supply a custom mutex implementation using the
7972 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
7973 ** before calling sqlite3_initialize() or any other public sqlite3_
7974 ** function that calls sqlite3_initialize().
7976 ** ^The sqlite3_mutex_alloc() routine allocates a new
7977 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
7978 ** routine returns NULL if it is unable to allocate the requested
7979 ** mutex. The argument to sqlite3_mutex_alloc() must one of these
7980 ** integer constants:
7983 ** <li> SQLITE_MUTEX_FAST
7984 ** <li> SQLITE_MUTEX_RECURSIVE
7985 ** <li> SQLITE_MUTEX_STATIC_MAIN
7986 ** <li> SQLITE_MUTEX_STATIC_MEM
7987 ** <li> SQLITE_MUTEX_STATIC_OPEN
7988 ** <li> SQLITE_MUTEX_STATIC_PRNG
7989 ** <li> SQLITE_MUTEX_STATIC_LRU
7990 ** <li> SQLITE_MUTEX_STATIC_PMEM
7991 ** <li> SQLITE_MUTEX_STATIC_APP1
7992 ** <li> SQLITE_MUTEX_STATIC_APP2
7993 ** <li> SQLITE_MUTEX_STATIC_APP3
7994 ** <li> SQLITE_MUTEX_STATIC_VFS1
7995 ** <li> SQLITE_MUTEX_STATIC_VFS2
7996 ** <li> SQLITE_MUTEX_STATIC_VFS3
7999 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
8000 ** cause sqlite3_mutex_alloc() to create
8001 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
8002 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
8003 ** The mutex implementation does not need to make a distinction
8004 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
8005 ** not want to. SQLite will only request a recursive mutex in
8006 ** cases where it really needs one. If a faster non-recursive mutex
8007 ** implementation is available on the host platform, the mutex subsystem
8008 ** might return such a mutex in response to SQLITE_MUTEX_FAST.
8010 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
8011 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
8012 ** a pointer to a static preexisting mutex. ^Nine static mutexes are
8013 ** used by the current version of SQLite. Future versions of SQLite
8014 ** may add additional static mutexes. Static mutexes are for internal
8015 ** use by SQLite only. Applications that use SQLite mutexes should
8016 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
8017 ** SQLITE_MUTEX_RECURSIVE.
8019 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
8020 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
8021 ** returns a different mutex on every call. ^For the static
8022 ** mutex types, the same mutex is returned on every call that has
8023 ** the same type number.
8025 ** ^The sqlite3_mutex_free() routine deallocates a previously
8026 ** allocated dynamic mutex. Attempting to deallocate a static
8027 ** mutex results in undefined behavior.
8029 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
8030 ** to enter a mutex. ^If another thread is already within the mutex,
8031 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
8032 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
8033 ** upon successful entry. ^(Mutexes created using
8034 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
8035 ** In such cases, the
8036 ** mutex must be exited an equal number of times before another thread
8037 ** can enter.)^ If the same thread tries to enter any mutex other
8038 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
8040 ** ^(Some systems (for example, Windows 95) do not support the operation
8041 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
8042 ** will always return SQLITE_BUSY. In most cases the SQLite core only uses
8043 ** sqlite3_mutex_try() as an optimization, so this is acceptable
8044 ** behavior. The exceptions are unix builds that set the
8045 ** SQLITE_ENABLE_SETLK_TIMEOUT build option. In that case a working
8046 ** sqlite3_mutex_try() is required.)^
8048 ** ^The sqlite3_mutex_leave() routine exits a mutex that was
8049 ** previously entered by the same thread. The behavior
8050 ** is undefined if the mutex is not currently entered by the
8051 ** calling thread or is not currently allocated.
8053 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(),
8054 ** sqlite3_mutex_leave(), or sqlite3_mutex_free() is a NULL pointer,
8055 ** then any of the four routines behaves as a no-op.
8057 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
8059 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
8060 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
8061 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
8062 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
8063 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
8066 ** CAPI3REF: Mutex Methods Object
8068 ** An instance of this structure defines the low-level routines
8069 ** used to allocate and use mutexes.
8071 ** Usually, the default mutex implementations provided by SQLite are
8072 ** sufficient, however the application has the option of substituting a custom
8073 ** implementation for specialized deployments or systems for which SQLite
8074 ** does not provide a suitable implementation. In this case, the application
8075 ** creates and populates an instance of this structure to pass
8076 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
8077 ** Additionally, an instance of this structure can be used as an
8078 ** output variable when querying the system for the current mutex
8079 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
8081 ** ^The xMutexInit method defined by this structure is invoked as
8082 ** part of system initialization by the sqlite3_initialize() function.
8083 ** ^The xMutexInit routine is called by SQLite exactly once for each
8084 ** effective call to [sqlite3_initialize()].
8086 ** ^The xMutexEnd method defined by this structure is invoked as
8087 ** part of system shutdown by the sqlite3_shutdown() function. The
8088 ** implementation of this method is expected to release all outstanding
8089 ** resources obtained by the mutex methods implementation, especially
8090 ** those obtained by the xMutexInit method. ^The xMutexEnd()
8091 ** interface is invoked exactly once for each call to [sqlite3_shutdown()].
8093 ** ^(The remaining seven methods defined by this structure (xMutexAlloc,
8094 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
8095 ** xMutexNotheld) implement the following interfaces (respectively):
8098 ** <li> [sqlite3_mutex_alloc()] </li>
8099 ** <li> [sqlite3_mutex_free()] </li>
8100 ** <li> [sqlite3_mutex_enter()] </li>
8101 ** <li> [sqlite3_mutex_try()] </li>
8102 ** <li> [sqlite3_mutex_leave()] </li>
8103 ** <li> [sqlite3_mutex_held()] </li>
8104 ** <li> [sqlite3_mutex_notheld()] </li>
8107 ** The only difference is that the public sqlite3_XXX functions enumerated
8108 ** above silently ignore any invocations that pass a NULL pointer instead
8109 ** of a valid mutex handle. The implementations of the methods defined
8110 ** by this structure are not required to handle this case. The results
8111 ** of passing a NULL pointer instead of a valid mutex handle are undefined
8112 ** (i.e. it is acceptable to provide an implementation that segfaults if
8113 ** it is passed a NULL pointer).
8115 ** The xMutexInit() method must be threadsafe. It must be harmless to
8116 ** invoke xMutexInit() multiple times within the same process and without
8117 ** intervening calls to xMutexEnd(). Second and subsequent calls to
8118 ** xMutexInit() must be no-ops.
8120 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
8121 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory
8122 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
8123 ** memory allocation for a fast or recursive mutex.
8125 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
8126 ** called, but only if the prior call to xMutexInit returned SQLITE_OK.
8127 ** If xMutexInit fails in any way, it is expected to clean up after itself
8128 ** prior to returning.
8130 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
8131 struct sqlite3_mutex_methods {
8132 int (*xMutexInit)(void);
8133 int (*xMutexEnd)(void);
8134 sqlite3_mutex *(*xMutexAlloc)(int);
8135 void (*xMutexFree)(sqlite3_mutex *);
8136 void (*xMutexEnter)(sqlite3_mutex *);
8137 int (*xMutexTry)(sqlite3_mutex *);
8138 void (*xMutexLeave)(sqlite3_mutex *);
8139 int (*xMutexHeld)(sqlite3_mutex *);
8140 int (*xMutexNotheld)(sqlite3_mutex *);
8144 ** CAPI3REF: Mutex Verification Routines
8146 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
8147 ** are intended for use inside assert() statements. The SQLite core
8148 ** never uses these routines except inside an assert() and applications
8149 ** are advised to follow the lead of the core. The SQLite core only
8150 ** provides implementations for these routines when it is compiled
8151 ** with the SQLITE_DEBUG flag. External mutex implementations
8152 ** are only required to provide these routines if SQLITE_DEBUG is
8153 ** defined and if NDEBUG is not defined.
8155 ** These routines should return true if the mutex in their argument
8156 ** is held or not held, respectively, by the calling thread.
8158 ** The implementation is not required to provide versions of these
8159 ** routines that actually work. If the implementation does not provide working
8160 ** versions of these routines, it should at least provide stubs that always
8161 ** return true so that one does not get spurious assertion failures.
8163 ** If the argument to sqlite3_mutex_held() is a NULL pointer then
8164 ** the routine should return 1. This seems counter-intuitive since
8165 ** clearly the mutex cannot be held if it does not exist. But
8166 ** the reason the mutex does not exist is because the build is not
8167 ** using mutexes. And we do not want the assert() containing the
8168 ** call to sqlite3_mutex_held() to fail, so a non-zero return is
8169 ** the appropriate thing to do. The sqlite3_mutex_notheld()
8170 ** interface should also return 1 when given a NULL pointer.
8173 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
8174 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
8178 ** CAPI3REF: Mutex Types
8180 ** The [sqlite3_mutex_alloc()] interface takes a single argument
8181 ** which is one of these integer constants.
8183 ** The set of static mutexes may change from one SQLite release to the
8184 ** next. Applications that override the built-in mutex logic must be
8185 ** prepared to accommodate additional static mutexes.
8187 #define SQLITE_MUTEX_FAST 0
8188 #define SQLITE_MUTEX_RECURSIVE 1
8189 #define SQLITE_MUTEX_STATIC_MAIN 2
8190 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
8191 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
8192 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
8193 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */
8194 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
8195 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
8196 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
8197 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */
8198 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */
8199 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */
8200 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */
8201 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */
8202 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */
8204 /* Legacy compatibility: */
8205 #define SQLITE_MUTEX_STATIC_MASTER 2
8209 ** CAPI3REF: Retrieve the mutex for a database connection
8212 ** ^This interface returns a pointer the [sqlite3_mutex] object that
8213 ** serializes access to the [database connection] given in the argument
8214 ** when the [threading mode] is Serialized.
8215 ** ^If the [threading mode] is Single-thread or Multi-thread then this
8216 ** routine returns a NULL pointer.
8218 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
8221 ** CAPI3REF: Low-Level Control Of Database Files
8223 ** KEYWORDS: {file control}
8225 ** ^The [sqlite3_file_control()] interface makes a direct call to the
8226 ** xFileControl method for the [sqlite3_io_methods] object associated
8227 ** with a particular database identified by the second argument. ^The
8228 ** name of the database is "main" for the main database or "temp" for the
8229 ** TEMP database, or the name that appears after the AS keyword for
8230 ** databases that are added using the [ATTACH] SQL command.
8231 ** ^A NULL pointer can be used in place of "main" to refer to the
8232 ** main database file.
8233 ** ^The third and fourth parameters to this routine
8234 ** are passed directly through to the second and third parameters of
8235 ** the xFileControl method. ^The return value of the xFileControl
8236 ** method becomes the return value of this routine.
8238 ** A few opcodes for [sqlite3_file_control()] are handled directly
8239 ** by the SQLite core and never invoke the
8240 ** sqlite3_io_methods.xFileControl method.
8241 ** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes
8242 ** a pointer to the underlying [sqlite3_file] object to be written into
8243 ** the space pointed to by the 4th parameter. The
8244 ** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns
8245 ** the [sqlite3_file] object associated with the journal file instead of
8246 ** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns
8247 ** a pointer to the underlying [sqlite3_vfs] object for the file.
8248 ** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter
8251 ** ^If the second parameter (zDbName) does not match the name of any
8252 ** open database file, then SQLITE_ERROR is returned. ^This error
8253 ** code is not remembered and will not be recalled by [sqlite3_errcode()]
8254 ** or [sqlite3_errmsg()]. The underlying xFileControl method might
8255 ** also return SQLITE_ERROR. There is no way to distinguish between
8256 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying
8257 ** xFileControl method.
8259 ** See also: [file control opcodes]
8261 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
8264 ** CAPI3REF: Testing Interface
8266 ** ^The sqlite3_test_control() interface is used to read out internal
8267 ** state of SQLite and to inject faults into SQLite for testing
8268 ** purposes. ^The first parameter is an operation code that determines
8269 ** the number, meaning, and operation of all subsequent parameters.
8271 ** This interface is not for use by applications. It exists solely
8272 ** for verifying the correct operation of the SQLite library. Depending
8273 ** on how the SQLite library is compiled, this interface might not exist.
8275 ** The details of the operation codes, their meanings, the parameters
8276 ** they take, and what they do are all subject to change without notice.
8277 ** Unlike most of the SQLite API, this function is not guaranteed to
8278 ** operate consistently from one release to the next.
8280 SQLITE_API int sqlite3_test_control(int op, ...);
8283 ** CAPI3REF: Testing Interface Operation Codes
8285 ** These constants are the valid operation code parameters used
8286 ** as the first argument to [sqlite3_test_control()].
8288 ** These parameters and their meanings are subject to change
8289 ** without notice. These values are for testing purposes only.
8290 ** Applications should not use any of these parameters or the
8291 ** [sqlite3_test_control()] interface.
8293 #define SQLITE_TESTCTRL_FIRST 5
8294 #define SQLITE_TESTCTRL_PRNG_SAVE 5
8295 #define SQLITE_TESTCTRL_PRNG_RESTORE 6
8296 #define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */
8297 #define SQLITE_TESTCTRL_FK_NO_ACTION 7
8298 #define SQLITE_TESTCTRL_BITVEC_TEST 8
8299 #define SQLITE_TESTCTRL_FAULT_INSTALL 9
8300 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
8301 #define SQLITE_TESTCTRL_PENDING_BYTE 11
8302 #define SQLITE_TESTCTRL_ASSERT 12
8303 #define SQLITE_TESTCTRL_ALWAYS 13
8304 #define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */
8305 #define SQLITE_TESTCTRL_JSON_SELFCHECK 14
8306 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15
8307 #define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */
8308 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */
8309 #define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17
8310 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18
8311 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */
8312 #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19
8313 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20
8314 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21
8315 #define SQLITE_TESTCTRL_BYTEORDER 22
8316 #define SQLITE_TESTCTRL_ISINIT 23
8317 #define SQLITE_TESTCTRL_SORTER_MMAP 24
8318 #define SQLITE_TESTCTRL_IMPOSTER 25
8319 #define SQLITE_TESTCTRL_PARSER_COVERAGE 26
8320 #define SQLITE_TESTCTRL_RESULT_INTREAL 27
8321 #define SQLITE_TESTCTRL_PRNG_SEED 28
8322 #define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29
8323 #define SQLITE_TESTCTRL_SEEK_COUNT 30
8324 #define SQLITE_TESTCTRL_TRACEFLAGS 31
8325 #define SQLITE_TESTCTRL_TUNE 32
8326 #define SQLITE_TESTCTRL_LOGEST 33
8327 #define SQLITE_TESTCTRL_USELONGDOUBLE 34
8328 #define SQLITE_TESTCTRL_LAST 34 /* Largest TESTCTRL */
8331 ** CAPI3REF: SQL Keyword Checking
8333 ** These routines provide access to the set of SQL language keywords
8334 ** recognized by SQLite. Applications can uses these routines to determine
8335 ** whether or not a specific identifier needs to be escaped (for example,
8336 ** by enclosing in double-quotes) so as not to confuse the parser.
8338 ** The sqlite3_keyword_count() interface returns the number of distinct
8339 ** keywords understood by SQLite.
8341 ** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and
8342 ** makes *Z point to that keyword expressed as UTF8 and writes the number
8343 ** of bytes in the keyword into *L. The string that *Z points to is not
8344 ** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns
8345 ** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z
8346 ** or L are NULL or invalid pointers then calls to
8347 ** sqlite3_keyword_name(N,Z,L) result in undefined behavior.
8349 ** The sqlite3_keyword_check(Z,L) interface checks to see whether or not
8350 ** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero
8351 ** if it is and zero if not.
8353 ** The parser used by SQLite is forgiving. It is often possible to use
8354 ** a keyword as an identifier as long as such use does not result in a
8355 ** parsing ambiguity. For example, the statement
8356 ** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and
8357 ** creates a new table named "BEGIN" with three columns named
8358 ** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid
8359 ** using keywords as identifiers. Common techniques used to avoid keyword
8360 ** name collisions include:
8362 ** <li> Put all identifier names inside double-quotes. This is the official
8363 ** SQL way to escape identifier names.
8364 ** <li> Put identifier names inside [...]. This is not standard SQL,
8365 ** but it is what SQL Server does and so lots of programmers use this
8367 ** <li> Begin every identifier with the letter "Z" as no SQL keywords start
8369 ** <li> Include a digit somewhere in every identifier name.
8372 ** Note that the number of keywords understood by SQLite can depend on
8373 ** compile-time options. For example, "VACUUM" is not a keyword if
8374 ** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also,
8375 ** new keywords may be added to future releases of SQLite.
8377 SQLITE_API int sqlite3_keyword_count(void);
8378 SQLITE_API int sqlite3_keyword_name(int,const char**,int*);
8379 SQLITE_API int sqlite3_keyword_check(const char*,int);
8382 ** CAPI3REF: Dynamic String Object
8383 ** KEYWORDS: {dynamic string}
8385 ** An instance of the sqlite3_str object contains a dynamically-sized
8386 ** string under construction.
8388 ** The lifecycle of an sqlite3_str object is as follows:
8390 ** <li> ^The sqlite3_str object is created using [sqlite3_str_new()].
8391 ** <li> ^Text is appended to the sqlite3_str object using various
8392 ** methods, such as [sqlite3_str_appendf()].
8393 ** <li> ^The sqlite3_str object is destroyed and the string it created
8394 ** is returned using the [sqlite3_str_finish()] interface.
8397 typedef struct sqlite3_str sqlite3_str;
8400 ** CAPI3REF: Create A New Dynamic String Object
8401 ** CONSTRUCTOR: sqlite3_str
8403 ** ^The [sqlite3_str_new(D)] interface allocates and initializes
8404 ** a new [sqlite3_str] object. To avoid memory leaks, the object returned by
8405 ** [sqlite3_str_new()] must be freed by a subsequent call to
8406 ** [sqlite3_str_finish(X)].
8408 ** ^The [sqlite3_str_new(D)] interface always returns a pointer to a
8409 ** valid [sqlite3_str] object, though in the event of an out-of-memory
8410 ** error the returned object might be a special singleton that will
8411 ** silently reject new text, always return SQLITE_NOMEM from
8412 ** [sqlite3_str_errcode()], always return 0 for
8413 ** [sqlite3_str_length()], and always return NULL from
8414 ** [sqlite3_str_finish(X)]. It is always safe to use the value
8415 ** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter
8416 ** to any of the other [sqlite3_str] methods.
8418 ** The D parameter to [sqlite3_str_new(D)] may be NULL. If the
8419 ** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum
8420 ** length of the string contained in the [sqlite3_str] object will be
8421 ** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead
8422 ** of [SQLITE_MAX_LENGTH].
8424 SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*);
8427 ** CAPI3REF: Finalize A Dynamic String
8428 ** DESTRUCTOR: sqlite3_str
8430 ** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X
8431 ** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()]
8432 ** that contains the constructed string. The calling application should
8433 ** pass the returned value to [sqlite3_free()] to avoid a memory leak.
8434 ** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any
8435 ** errors were encountered during construction of the string. ^The
8436 ** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the
8437 ** string in [sqlite3_str] object X is zero bytes long.
8439 SQLITE_API char *sqlite3_str_finish(sqlite3_str*);
8442 ** CAPI3REF: Add Content To A Dynamic String
8443 ** METHOD: sqlite3_str
8445 ** These interfaces add content to an sqlite3_str object previously obtained
8446 ** from [sqlite3_str_new()].
8448 ** ^The [sqlite3_str_appendf(X,F,...)] and
8449 ** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf]
8450 ** functionality of SQLite to append formatted text onto the end of
8451 ** [sqlite3_str] object X.
8453 ** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S
8454 ** onto the end of the [sqlite3_str] object X. N must be non-negative.
8455 ** S must contain at least N non-zero bytes of content. To append a
8456 ** zero-terminated string in its entirety, use the [sqlite3_str_appendall()]
8459 ** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of
8460 ** zero-terminated string S onto the end of [sqlite3_str] object X.
8462 ** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the
8463 ** single-byte character C onto the end of [sqlite3_str] object X.
8464 ** ^This method can be used, for example, to add whitespace indentation.
8466 ** ^The [sqlite3_str_reset(X)] method resets the string under construction
8467 ** inside [sqlite3_str] object X back to zero bytes in length.
8469 ** These methods do not return a result code. ^If an error occurs, that fact
8470 ** is recorded in the [sqlite3_str] object and can be recovered by a
8471 ** subsequent call to [sqlite3_str_errcode(X)].
8473 SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...);
8474 SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list);
8475 SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N);
8476 SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn);
8477 SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C);
8478 SQLITE_API void sqlite3_str_reset(sqlite3_str*);
8481 ** CAPI3REF: Status Of A Dynamic String
8482 ** METHOD: sqlite3_str
8484 ** These interfaces return the current status of an [sqlite3_str] object.
8486 ** ^If any prior errors have occurred while constructing the dynamic string
8487 ** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return
8488 ** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns
8489 ** [SQLITE_NOMEM] following any out-of-memory error, or
8490 ** [SQLITE_TOOBIG] if the size of the dynamic string exceeds
8491 ** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors.
8493 ** ^The [sqlite3_str_length(X)] method returns the current length, in bytes,
8494 ** of the dynamic string under construction in [sqlite3_str] object X.
8495 ** ^The length returned by [sqlite3_str_length(X)] does not include the
8496 ** zero-termination byte.
8498 ** ^The [sqlite3_str_value(X)] method returns a pointer to the current
8499 ** content of the dynamic string under construction in X. The value
8500 ** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X
8501 ** and might be freed or altered by any subsequent method on the same
8502 ** [sqlite3_str] object. Applications must not used the pointer returned
8503 ** [sqlite3_str_value(X)] after any subsequent method call on the same
8504 ** object. ^Applications may change the content of the string returned
8505 ** by [sqlite3_str_value(X)] as long as they do not write into any bytes
8506 ** outside the range of 0 to [sqlite3_str_length(X)] and do not read or
8507 ** write any byte after any subsequent sqlite3_str method call.
8509 SQLITE_API int sqlite3_str_errcode(sqlite3_str*);
8510 SQLITE_API int sqlite3_str_length(sqlite3_str*);
8511 SQLITE_API char *sqlite3_str_value(sqlite3_str*);
8514 ** CAPI3REF: SQLite Runtime Status
8516 ** ^These interfaces are used to retrieve runtime status information
8517 ** about the performance of SQLite, and optionally to reset various
8518 ** highwater marks. ^The first argument is an integer code for
8519 ** the specific parameter to measure. ^(Recognized integer codes
8520 ** are of the form [status parameters | SQLITE_STATUS_...].)^
8521 ** ^The current value of the parameter is returned into *pCurrent.
8522 ** ^The highest recorded value is returned in *pHighwater. ^If the
8523 ** resetFlag is true, then the highest record value is reset after
8524 ** *pHighwater is written. ^(Some parameters do not record the highest
8525 ** value. For those parameters
8526 ** nothing is written into *pHighwater and the resetFlag is ignored.)^
8527 ** ^(Other parameters record only the highwater mark and not the current
8528 ** value. For these latter parameters nothing is written into *pCurrent.)^
8530 ** ^The sqlite3_status() and sqlite3_status64() routines return
8531 ** SQLITE_OK on success and a non-zero [error code] on failure.
8533 ** If either the current value or the highwater mark is too large to
8534 ** be represented by a 32-bit integer, then the values returned by
8535 ** sqlite3_status() are undefined.
8537 ** See also: [sqlite3_db_status()]
8539 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
8540 SQLITE_API int sqlite3_status64(
8542 sqlite3_int64 *pCurrent,
8543 sqlite3_int64 *pHighwater,
8549 ** CAPI3REF: Status Parameters
8550 ** KEYWORDS: {status parameters}
8552 ** These integer constants designate various run-time status parameters
8553 ** that can be returned by [sqlite3_status()].
8556 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
8557 ** <dd>This parameter is the current amount of memory checked out
8558 ** using [sqlite3_malloc()], either directly or indirectly. The
8559 ** figure includes calls made to [sqlite3_malloc()] by the application
8560 ** and internal memory usage by the SQLite library. Auxiliary page-cache
8561 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
8562 ** this parameter. The amount returned is the sum of the allocation
8563 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
8565 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
8566 ** <dd>This parameter records the largest memory allocation request
8567 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
8568 ** internal equivalents). Only the value returned in the
8569 ** *pHighwater parameter to [sqlite3_status()] is of interest.
8570 ** The value written into the *pCurrent parameter is undefined.</dd>)^
8572 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
8573 ** <dd>This parameter records the number of separate memory allocations
8574 ** currently checked out.</dd>)^
8576 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
8577 ** <dd>This parameter returns the number of pages used out of the
8578 ** [pagecache memory allocator] that was configured using
8579 ** [SQLITE_CONFIG_PAGECACHE]. The
8580 ** value returned is in pages, not in bytes.</dd>)^
8582 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
8583 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
8584 ** <dd>This parameter returns the number of bytes of page cache
8585 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
8586 ** buffer and where forced to overflow to [sqlite3_malloc()]. The
8587 ** returned value includes allocations that overflowed because they
8588 ** where too large (they were larger than the "sz" parameter to
8589 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
8590 ** no space was left in the page cache.</dd>)^
8592 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
8593 ** <dd>This parameter records the largest memory allocation request
8594 ** handed to the [pagecache memory allocator]. Only the value returned in the
8595 ** *pHighwater parameter to [sqlite3_status()] is of interest.
8596 ** The value written into the *pCurrent parameter is undefined.</dd>)^
8598 ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt>
8599 ** <dd>No longer used.</dd>
8601 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
8602 ** <dd>No longer used.</dd>
8604 ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
8605 ** <dd>No longer used.</dd>
8607 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
8608 ** <dd>The *pHighwater parameter records the deepest parser stack.
8609 ** The *pCurrent value is undefined. The *pHighwater value is only
8610 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
8613 ** New status parameters may be added from time to time.
8615 #define SQLITE_STATUS_MEMORY_USED 0
8616 #define SQLITE_STATUS_PAGECACHE_USED 1
8617 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
8618 #define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */
8619 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */
8620 #define SQLITE_STATUS_MALLOC_SIZE 5
8621 #define SQLITE_STATUS_PARSER_STACK 6
8622 #define SQLITE_STATUS_PAGECACHE_SIZE 7
8623 #define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */
8624 #define SQLITE_STATUS_MALLOC_COUNT 9
8627 ** CAPI3REF: Database Connection Status
8630 ** ^This interface is used to retrieve runtime status information
8631 ** about a single [database connection]. ^The first argument is the
8632 ** database connection object to be interrogated. ^The second argument
8633 ** is an integer constant, taken from the set of
8634 ** [SQLITE_DBSTATUS options], that
8635 ** determines the parameter to interrogate. The set of
8636 ** [SQLITE_DBSTATUS options] is likely
8637 ** to grow in future releases of SQLite.
8639 ** ^The current value of the requested parameter is written into *pCur
8640 ** and the highest instantaneous value is written into *pHiwtr. ^If
8641 ** the resetFlg is true, then the highest instantaneous value is
8642 ** reset back down to the current value.
8644 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
8645 ** non-zero [error code] on failure.
8647 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
8649 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
8652 ** CAPI3REF: Status Parameters for database connections
8653 ** KEYWORDS: {SQLITE_DBSTATUS options}
8655 ** These constants are the available integer "verbs" that can be passed as
8656 ** the second argument to the [sqlite3_db_status()] interface.
8658 ** New verbs may be added in future releases of SQLite. Existing verbs
8659 ** might be discontinued. Applications should check the return code from
8660 ** [sqlite3_db_status()] to make sure that the call worked.
8661 ** The [sqlite3_db_status()] interface will return a non-zero error code
8662 ** if a discontinued or unsupported verb is invoked.
8665 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
8666 ** <dd>This parameter returns the number of lookaside memory slots currently
8667 ** checked out.</dd>)^
8669 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
8670 ** <dd>This parameter returns the number of malloc attempts that were
8671 ** satisfied using lookaside memory. Only the high-water value is meaningful;
8672 ** the current value is always zero.)^
8674 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
8675 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
8676 ** <dd>This parameter returns the number malloc attempts that might have
8677 ** been satisfied using lookaside memory but failed due to the amount of
8678 ** memory requested being larger than the lookaside slot size.
8679 ** Only the high-water value is meaningful;
8680 ** the current value is always zero.)^
8682 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
8683 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
8684 ** <dd>This parameter returns the number malloc attempts that might have
8685 ** been satisfied using lookaside memory but failed due to all lookaside
8686 ** memory already being in use.
8687 ** Only the high-water value is meaningful;
8688 ** the current value is always zero.)^
8690 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
8691 ** <dd>This parameter returns the approximate number of bytes of heap
8692 ** memory used by all pager caches associated with the database connection.)^
8693 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
8695 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]]
8696 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt>
8697 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a
8698 ** pager cache is shared between two or more connections the bytes of heap
8699 ** memory used by that pager cache is divided evenly between the attached
8700 ** connections.)^ In other words, if none of the pager caches associated
8701 ** with the database connection are shared, this request returns the same
8702 ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are
8703 ** shared, the value returned by this call will be smaller than that returned
8704 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with
8705 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.
8707 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
8708 ** <dd>This parameter returns the approximate number of bytes of heap
8709 ** memory used to store the schema for all databases associated
8710 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^
8711 ** ^The full amount of memory used by the schemas is reported, even if the
8712 ** schema memory is shared with other database connections due to
8713 ** [shared cache mode] being enabled.
8714 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
8716 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
8717 ** <dd>This parameter returns the approximate number of bytes of heap
8718 ** and lookaside memory used by all prepared statements associated with
8719 ** the database connection.)^
8720 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
8723 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
8724 ** <dd>This parameter returns the number of pager cache hits that have
8725 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
8729 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
8730 ** <dd>This parameter returns the number of pager cache misses that have
8731 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
8735 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
8736 ** <dd>This parameter returns the number of dirty cache entries that have
8737 ** been written to disk. Specifically, the number of pages written to the
8738 ** wal file in wal mode databases, or the number of pages written to the
8739 ** database file in rollback mode databases. Any pages written as part of
8740 ** transaction rollback or database recovery operations are not included.
8741 ** If an IO or other error occurs while writing a page to disk, the effect
8742 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
8743 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
8746 ** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt>
8747 ** <dd>This parameter returns the number of dirty cache entries that have
8748 ** been written to disk in the middle of a transaction due to the page
8749 ** cache overflowing. Transactions are more efficient if they are written
8750 ** to disk all at once. When pages spill mid-transaction, that introduces
8751 ** additional overhead. This parameter can be used help identify
8752 ** inefficiencies that can be resolved by increasing the cache size.
8755 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
8756 ** <dd>This parameter returns zero for the current value if and only if
8757 ** all foreign key constraints (deferred or immediate) have been
8758 ** resolved.)^ ^The highwater mark is always 0.
8762 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0
8763 #define SQLITE_DBSTATUS_CACHE_USED 1
8764 #define SQLITE_DBSTATUS_SCHEMA_USED 2
8765 #define SQLITE_DBSTATUS_STMT_USED 3
8766 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
8767 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
8768 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
8769 #define SQLITE_DBSTATUS_CACHE_HIT 7
8770 #define SQLITE_DBSTATUS_CACHE_MISS 8
8771 #define SQLITE_DBSTATUS_CACHE_WRITE 9
8772 #define SQLITE_DBSTATUS_DEFERRED_FKS 10
8773 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11
8774 #define SQLITE_DBSTATUS_CACHE_SPILL 12
8775 #define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */
8779 ** CAPI3REF: Prepared Statement Status
8780 ** METHOD: sqlite3_stmt
8782 ** ^(Each prepared statement maintains various
8783 ** [SQLITE_STMTSTATUS counters] that measure the number
8784 ** of times it has performed specific operations.)^ These counters can
8785 ** be used to monitor the performance characteristics of the prepared
8786 ** statements. For example, if the number of table steps greatly exceeds
8787 ** the number of table searches or result rows, that would tend to indicate
8788 ** that the prepared statement is using a full table scan rather than
8791 ** ^(This interface is used to retrieve and reset counter values from
8792 ** a [prepared statement]. The first argument is the prepared statement
8793 ** object to be interrogated. The second argument
8794 ** is an integer code for a specific [SQLITE_STMTSTATUS counter]
8795 ** to be interrogated.)^
8796 ** ^The current value of the requested counter is returned.
8797 ** ^If the resetFlg is true, then the counter is reset to zero after this
8798 ** interface call returns.
8800 ** See also: [sqlite3_status()] and [sqlite3_db_status()].
8802 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
8805 ** CAPI3REF: Status Parameters for prepared statements
8806 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
8808 ** These preprocessor macros define integer codes that name counter
8809 ** values associated with the [sqlite3_stmt_status()] interface.
8810 ** The meanings of the various counters are as follows:
8813 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
8814 ** <dd>^This is the number of times that SQLite has stepped forward in
8815 ** a table as part of a full table scan. Large numbers for this counter
8816 ** may indicate opportunities for performance improvement through
8817 ** careful use of indices.</dd>
8819 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
8820 ** <dd>^This is the number of sort operations that have occurred.
8821 ** A non-zero value in this counter may indicate an opportunity to
8822 ** improvement performance through careful use of indices.</dd>
8824 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
8825 ** <dd>^This is the number of rows inserted into transient indices that
8826 ** were created automatically in order to help joins run faster.
8827 ** A non-zero value in this counter may indicate an opportunity to
8828 ** improvement performance by adding permanent indices that do not
8829 ** need to be reinitialized each time the statement is run.</dd>
8831 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
8832 ** <dd>^This is the number of virtual machine operations executed
8833 ** by the prepared statement if that number is less than or equal
8834 ** to 2147483647. The number of virtual machine operations can be
8835 ** used as a proxy for the total work done by the prepared statement.
8836 ** If the number of virtual machine operations exceeds 2147483647
8837 ** then the value returned by this statement status code is undefined.
8839 ** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt>
8840 ** <dd>^This is the number of times that the prepare statement has been
8841 ** automatically regenerated due to schema changes or changes to
8842 ** [bound parameters] that might affect the query plan.
8844 ** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt>
8845 ** <dd>^This is the number of times that the prepared statement has
8846 ** been run. A single "run" for the purposes of this counter is one
8847 ** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()].
8848 ** The counter is incremented on the first [sqlite3_step()] call of each
8851 ** [[SQLITE_STMTSTATUS_FILTER_MISS]]
8852 ** [[SQLITE_STMTSTATUS_FILTER HIT]]
8853 ** <dt>SQLITE_STMTSTATUS_FILTER_HIT<br>
8854 ** SQLITE_STMTSTATUS_FILTER_MISS</dt>
8855 ** <dd>^SQLITE_STMTSTATUS_FILTER_HIT is the number of times that a join
8856 ** step was bypassed because a Bloom filter returned not-found. The
8857 ** corresponding SQLITE_STMTSTATUS_FILTER_MISS value is the number of
8858 ** times that the Bloom filter returned a find, and thus the join step
8859 ** had to be processed as normal.
8861 ** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt>
8862 ** <dd>^This is the approximate number of bytes of heap memory
8863 ** used to store the prepared statement. ^This value is not actually
8864 ** a counter, and so the resetFlg parameter to sqlite3_stmt_status()
8865 ** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED.
8869 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
8870 #define SQLITE_STMTSTATUS_SORT 2
8871 #define SQLITE_STMTSTATUS_AUTOINDEX 3
8872 #define SQLITE_STMTSTATUS_VM_STEP 4
8873 #define SQLITE_STMTSTATUS_REPREPARE 5
8874 #define SQLITE_STMTSTATUS_RUN 6
8875 #define SQLITE_STMTSTATUS_FILTER_MISS 7
8876 #define SQLITE_STMTSTATUS_FILTER_HIT 8
8877 #define SQLITE_STMTSTATUS_MEMUSED 99
8880 ** CAPI3REF: Custom Page Cache Object
8882 ** The sqlite3_pcache type is opaque. It is implemented by
8883 ** the pluggable module. The SQLite core has no knowledge of
8884 ** its size or internal structure and never deals with the
8885 ** sqlite3_pcache object except by holding and passing pointers
8888 ** See [sqlite3_pcache_methods2] for additional information.
8890 typedef struct sqlite3_pcache sqlite3_pcache;
8893 ** CAPI3REF: Custom Page Cache Object
8895 ** The sqlite3_pcache_page object represents a single page in the
8896 ** page cache. The page cache will allocate instances of this
8897 ** object. Various methods of the page cache use pointers to instances
8898 ** of this object as parameters or as their return value.
8900 ** See [sqlite3_pcache_methods2] for additional information.
8902 typedef struct sqlite3_pcache_page sqlite3_pcache_page;
8903 struct sqlite3_pcache_page {
8904 void *pBuf; /* The content of the page */
8905 void *pExtra; /* Extra information associated with the page */
8909 ** CAPI3REF: Application Defined Page Cache.
8910 ** KEYWORDS: {page cache}
8912 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
8913 ** register an alternative page cache implementation by passing in an
8914 ** instance of the sqlite3_pcache_methods2 structure.)^
8915 ** In many applications, most of the heap memory allocated by
8916 ** SQLite is used for the page cache.
8917 ** By implementing a
8918 ** custom page cache using this API, an application can better control
8919 ** the amount of memory consumed by SQLite, the way in which
8920 ** that memory is allocated and released, and the policies used to
8921 ** determine exactly which parts of a database file are cached and for
8924 ** The alternative page cache mechanism is an
8925 ** extreme measure that is only needed by the most demanding applications.
8926 ** The built-in page cache is recommended for most uses.
8928 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
8929 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence
8930 ** the application may discard the parameter after the call to
8931 ** [sqlite3_config()] returns.)^
8933 ** [[the xInit() page cache method]]
8934 ** ^(The xInit() method is called once for each effective
8935 ** call to [sqlite3_initialize()])^
8936 ** (usually only once during the lifetime of the process). ^(The xInit()
8937 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
8938 ** The intent of the xInit() method is to set up global data structures
8939 ** required by the custom page cache implementation.
8940 ** ^(If the xInit() method is NULL, then the
8941 ** built-in default page cache is used instead of the application defined
8944 ** [[the xShutdown() page cache method]]
8945 ** ^The xShutdown() method is called by [sqlite3_shutdown()].
8946 ** It can be used to clean up
8947 ** any outstanding resources before process shutdown, if required.
8948 ** ^The xShutdown() method may be NULL.
8950 ** ^SQLite automatically serializes calls to the xInit method,
8951 ** so the xInit method need not be threadsafe. ^The
8952 ** xShutdown method is only called from [sqlite3_shutdown()] so it does
8953 ** not need to be threadsafe either. All other methods must be threadsafe
8954 ** in multithreaded applications.
8956 ** ^SQLite will never invoke xInit() more than once without an intervening
8957 ** call to xShutdown().
8959 ** [[the xCreate() page cache methods]]
8960 ** ^SQLite invokes the xCreate() method to construct a new cache instance.
8961 ** SQLite will typically create one cache instance for each open database file,
8962 ** though this is not guaranteed. ^The
8963 ** first parameter, szPage, is the size in bytes of the pages that must
8964 ** be allocated by the cache. ^szPage will always a power of two. ^The
8965 ** second parameter szExtra is a number of bytes of extra storage
8966 ** associated with each page cache entry. ^The szExtra parameter will
8967 ** a number less than 250. SQLite will use the
8968 ** extra szExtra bytes on each page to store metadata about the underlying
8969 ** database page on disk. The value passed into szExtra depends
8970 ** on the SQLite version, the target platform, and how SQLite was compiled.
8971 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being
8972 ** created will be used to cache database pages of a file stored on disk, or
8973 ** false if it is used for an in-memory database. The cache implementation
8974 ** does not have to do anything special based with the value of bPurgeable;
8975 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
8976 ** never invoke xUnpin() except to deliberately delete a page.
8977 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
8978 ** false will always have the "discard" flag set to true.
8979 ** ^Hence, a cache created with bPurgeable false will
8980 ** never contain any unpinned pages.
8982 ** [[the xCachesize() page cache method]]
8983 ** ^(The xCachesize() method may be called at any time by SQLite to set the
8984 ** suggested maximum cache-size (number of pages stored by) the cache
8985 ** instance passed as the first argument. This is the value configured using
8986 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
8987 ** parameter, the implementation is not required to do anything with this
8988 ** value; it is advisory only.
8990 ** [[the xPagecount() page cache methods]]
8991 ** The xPagecount() method must return the number of pages currently
8992 ** stored in the cache, both pinned and unpinned.
8994 ** [[the xFetch() page cache methods]]
8995 ** The xFetch() method locates a page in the cache and returns a pointer to
8996 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
8997 ** The pBuf element of the returned sqlite3_pcache_page object will be a
8998 ** pointer to a buffer of szPage bytes used to store the content of a
8999 ** single database page. The pExtra element of sqlite3_pcache_page will be
9000 ** a pointer to the szExtra bytes of extra storage that SQLite has requested
9001 ** for each entry in the page cache.
9003 ** The page to be fetched is determined by the key. ^The minimum key value
9004 ** is 1. After it has been retrieved using xFetch, the page is considered
9007 ** If the requested page is already in the page cache, then the page cache
9008 ** implementation must return a pointer to the page buffer with its content
9009 ** intact. If the requested page is not already in the cache, then the
9010 ** cache implementation should use the value of the createFlag
9011 ** parameter to help it determined what action to take:
9013 ** <table border=1 width=85% align=center>
9014 ** <tr><th> createFlag <th> Behavior when page is not already in cache
9015 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
9016 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
9017 ** Otherwise return NULL.
9018 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
9019 ** NULL if allocating a new page is effectively impossible.
9022 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
9023 ** will only use a createFlag of 2 after a prior call with a createFlag of 1
9024 ** failed.)^ In between the xFetch() calls, SQLite may
9025 ** attempt to unpin one or more cache pages by spilling the content of
9026 ** pinned pages to disk and synching the operating system disk cache.
9028 ** [[the xUnpin() page cache method]]
9029 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
9030 ** as its second argument. If the third parameter, discard, is non-zero,
9031 ** then the page must be evicted from the cache.
9032 ** ^If the discard parameter is
9033 ** zero, then the page may be discarded or retained at the discretion of
9034 ** page cache implementation. ^The page cache implementation
9035 ** may choose to evict unpinned pages at any time.
9037 ** The cache must not perform any reference counting. A single
9038 ** call to xUnpin() unpins the page regardless of the number of prior calls
9041 ** [[the xRekey() page cache methods]]
9042 ** The xRekey() method is used to change the key value associated with the
9043 ** page passed as the second argument. If the cache
9044 ** previously contains an entry associated with newKey, it must be
9045 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not
9048 ** When SQLite calls the xTruncate() method, the cache must discard all
9049 ** existing cache entries with page numbers (keys) greater than or equal
9050 ** to the value of the iLimit parameter passed to xTruncate(). If any
9051 ** of these pages are pinned, they are implicitly unpinned, meaning that
9052 ** they can be safely discarded.
9054 ** [[the xDestroy() page cache method]]
9055 ** ^The xDestroy() method is used to delete a cache allocated by xCreate().
9056 ** All resources associated with the specified cache should be freed. ^After
9057 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
9058 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2
9061 ** [[the xShrink() page cache method]]
9062 ** ^SQLite invokes the xShrink() method when it wants the page cache to
9063 ** free up as much of heap memory as possible. The page cache implementation
9064 ** is not obligated to free any memory, but well-behaved implementations should
9067 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
9068 struct sqlite3_pcache_methods2 {
9071 int (*xInit)(void*);
9072 void (*xShutdown)(void*);
9073 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
9074 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
9075 int (*xPagecount)(sqlite3_pcache*);
9076 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
9077 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
9078 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
9079 unsigned oldKey, unsigned newKey);
9080 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
9081 void (*xDestroy)(sqlite3_pcache*);
9082 void (*xShrink)(sqlite3_pcache*);
9086 ** This is the obsolete pcache_methods object that has now been replaced
9087 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
9088 ** retained in the header file for backwards compatibility only.
9090 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
9091 struct sqlite3_pcache_methods {
9093 int (*xInit)(void*);
9094 void (*xShutdown)(void*);
9095 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
9096 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
9097 int (*xPagecount)(sqlite3_pcache*);
9098 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
9099 void (*xUnpin)(sqlite3_pcache*, void*, int discard);
9100 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
9101 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
9102 void (*xDestroy)(sqlite3_pcache*);
9107 ** CAPI3REF: Online Backup Object
9109 ** The sqlite3_backup object records state information about an ongoing
9110 ** online backup operation. ^The sqlite3_backup object is created by
9111 ** a call to [sqlite3_backup_init()] and is destroyed by a call to
9112 ** [sqlite3_backup_finish()].
9114 ** See Also: [Using the SQLite Online Backup API]
9116 typedef struct sqlite3_backup sqlite3_backup;
9119 ** CAPI3REF: Online Backup API.
9121 ** The backup API copies the content of one database into another.
9122 ** It is useful either for creating backups of databases or
9123 ** for copying in-memory databases to or from persistent files.
9125 ** See Also: [Using the SQLite Online Backup API]
9127 ** ^SQLite holds a write transaction open on the destination database file
9128 ** for the duration of the backup operation.
9129 ** ^The source database is read-locked only while it is being read;
9130 ** it is not locked continuously for the entire backup operation.
9131 ** ^Thus, the backup may be performed on a live source database without
9132 ** preventing other database connections from
9133 ** reading or writing to the source database while the backup is underway.
9135 ** ^(To perform a backup operation:
9137 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the
9139 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
9140 ** the data between the two databases, and finally
9141 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources
9142 ** associated with the backup operation.
9144 ** There should be exactly one call to sqlite3_backup_finish() for each
9145 ** successful call to sqlite3_backup_init().
9147 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
9149 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
9150 ** [database connection] associated with the destination database
9151 ** and the database name, respectively.
9152 ** ^The database name is "main" for the main database, "temp" for the
9153 ** temporary database, or the name specified after the AS keyword in
9154 ** an [ATTACH] statement for an attached database.
9155 ** ^The S and M arguments passed to
9156 ** sqlite3_backup_init(D,N,S,M) identify the [database connection]
9157 ** and database name of the source database, respectively.
9158 ** ^The source and destination [database connections] (parameters S and D)
9159 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
9162 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if
9163 ** there is already a read or read-write transaction open on the
9164 ** destination database.
9166 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
9167 ** returned and an error code and error message are stored in the
9168 ** destination [database connection] D.
9169 ** ^The error code and message for the failed call to sqlite3_backup_init()
9170 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
9171 ** [sqlite3_errmsg16()] functions.
9172 ** ^A successful call to sqlite3_backup_init() returns a pointer to an
9173 ** [sqlite3_backup] object.
9174 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
9175 ** sqlite3_backup_finish() functions to perform the specified backup
9178 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
9180 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
9181 ** the source and destination databases specified by [sqlite3_backup] object B.
9182 ** ^If N is negative, all remaining source pages are copied.
9183 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
9184 ** are still more pages to be copied, then the function returns [SQLITE_OK].
9185 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
9186 ** from source to destination, then it returns [SQLITE_DONE].
9187 ** ^If an error occurs while running sqlite3_backup_step(B,N),
9188 ** then an [error code] is returned. ^As well as [SQLITE_OK] and
9189 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
9190 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
9191 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
9193 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
9195 ** <li> the destination database was opened read-only, or
9196 ** <li> the destination database is using write-ahead-log journaling
9197 ** and the destination and source page sizes differ, or
9198 ** <li> the destination database is an in-memory database and the
9199 ** destination and source page sizes differ.
9202 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
9203 ** the [sqlite3_busy_handler | busy-handler function]
9204 ** is invoked (if one is specified). ^If the
9205 ** busy-handler returns non-zero before the lock is available, then
9206 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
9207 ** sqlite3_backup_step() can be retried later. ^If the source
9208 ** [database connection]
9209 ** is being used to write to the source database when sqlite3_backup_step()
9210 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
9211 ** case the call to sqlite3_backup_step() can be retried later on. ^(If
9212 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
9213 ** [SQLITE_READONLY] is returned, then
9214 ** there is no point in retrying the call to sqlite3_backup_step(). These
9215 ** errors are considered fatal.)^ The application must accept
9216 ** that the backup operation has failed and pass the backup operation handle
9217 ** to the sqlite3_backup_finish() to release associated resources.
9219 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock
9220 ** on the destination file. ^The exclusive lock is not released until either
9221 ** sqlite3_backup_finish() is called or the backup operation is complete
9222 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
9223 ** sqlite3_backup_step() obtains a [shared lock] on the source database that
9224 ** lasts for the duration of the sqlite3_backup_step() call.
9225 ** ^Because the source database is not locked between calls to
9226 ** sqlite3_backup_step(), the source database may be modified mid-way
9227 ** through the backup process. ^If the source database is modified by an
9228 ** external process or via a database connection other than the one being
9229 ** used by the backup operation, then the backup will be automatically
9230 ** restarted by the next call to sqlite3_backup_step(). ^If the source
9231 ** database is modified by the using the same database connection as is used
9232 ** by the backup operation, then the backup database is automatically
9233 ** updated at the same time.
9235 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
9237 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
9238 ** application wishes to abandon the backup operation, the application
9239 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
9240 ** ^The sqlite3_backup_finish() interfaces releases all
9241 ** resources associated with the [sqlite3_backup] object.
9242 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
9243 ** active write-transaction on the destination database is rolled back.
9244 ** The [sqlite3_backup] object is invalid
9245 ** and may not be used following a call to sqlite3_backup_finish().
9247 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
9248 ** sqlite3_backup_step() errors occurred, regardless or whether or not
9249 ** sqlite3_backup_step() completed.
9250 ** ^If an out-of-memory condition or IO error occurred during any prior
9251 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
9252 ** sqlite3_backup_finish() returns the corresponding [error code].
9254 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
9255 ** is not a permanent error and does not affect the return value of
9256 ** sqlite3_backup_finish().
9258 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
9259 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
9261 ** ^The sqlite3_backup_remaining() routine returns the number of pages still
9262 ** to be backed up at the conclusion of the most recent sqlite3_backup_step().
9263 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages
9264 ** in the source database at the conclusion of the most recent
9265 ** sqlite3_backup_step().
9266 ** ^(The values returned by these functions are only updated by
9267 ** sqlite3_backup_step(). If the source database is modified in a way that
9268 ** changes the size of the source database or the number of pages remaining,
9269 ** those changes are not reflected in the output of sqlite3_backup_pagecount()
9270 ** and sqlite3_backup_remaining() until after the next
9271 ** sqlite3_backup_step().)^
9273 ** <b>Concurrent Usage of Database Handles</b>
9275 ** ^The source [database connection] may be used by the application for other
9276 ** purposes while a backup operation is underway or being initialized.
9277 ** ^If SQLite is compiled and configured to support threadsafe database
9278 ** connections, then the source database connection may be used concurrently
9279 ** from within other threads.
9281 ** However, the application must guarantee that the destination
9282 ** [database connection] is not passed to any other API (by any thread) after
9283 ** sqlite3_backup_init() is called and before the corresponding call to
9284 ** sqlite3_backup_finish(). SQLite does not currently check to see
9285 ** if the application incorrectly accesses the destination [database connection]
9286 ** and so no error code is reported, but the operations may malfunction
9287 ** nevertheless. Use of the destination database connection while a
9288 ** backup is in progress might also cause a mutex deadlock.
9290 ** If running in [shared cache mode], the application must
9291 ** guarantee that the shared cache used by the destination database
9292 ** is not accessed while the backup is running. In practice this means
9293 ** that the application must guarantee that the disk file being
9294 ** backed up to is not accessed by any connection within the process,
9295 ** not just the specific connection that was passed to sqlite3_backup_init().
9297 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple
9298 ** threads may safely make multiple concurrent calls to sqlite3_backup_step().
9299 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
9300 ** APIs are not strictly speaking threadsafe. If they are invoked at the
9301 ** same time as another thread is invoking sqlite3_backup_step() it is
9302 ** possible that they return invalid values.
9304 SQLITE_API sqlite3_backup *sqlite3_backup_init(
9305 sqlite3 *pDest, /* Destination database handle */
9306 const char *zDestName, /* Destination database name */
9307 sqlite3 *pSource, /* Source database handle */
9308 const char *zSourceName /* Source database name */
9310 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
9311 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
9312 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
9313 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
9316 ** CAPI3REF: Unlock Notification
9319 ** ^When running in shared-cache mode, a database operation may fail with
9320 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
9321 ** individual tables within the shared-cache cannot be obtained. See
9322 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
9323 ** ^This API may be used to register a callback that SQLite will invoke
9324 ** when the connection currently holding the required lock relinquishes it.
9325 ** ^This API is only available if the library was compiled with the
9326 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
9328 ** See Also: [Using the SQLite Unlock Notification Feature].
9330 ** ^Shared-cache locks are released when a database connection concludes
9331 ** its current transaction, either by committing it or rolling it back.
9333 ** ^When a connection (known as the blocked connection) fails to obtain a
9334 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
9335 ** identity of the database connection (the blocking connection) that
9336 ** has locked the required resource is stored internally. ^After an
9337 ** application receives an SQLITE_LOCKED error, it may call the
9338 ** sqlite3_unlock_notify() method with the blocked connection handle as
9339 ** the first argument to register for a callback that will be invoked
9340 ** when the blocking connections current transaction is concluded. ^The
9341 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
9342 ** call that concludes the blocking connection's transaction.
9344 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
9345 ** there is a chance that the blocking connection will have already
9346 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
9347 ** If this happens, then the specified callback is invoked immediately,
9348 ** from within the call to sqlite3_unlock_notify().)^
9350 ** ^If the blocked connection is attempting to obtain a write-lock on a
9351 ** shared-cache table, and more than one other connection currently holds
9352 ** a read-lock on the same table, then SQLite arbitrarily selects one of
9353 ** the other connections to use as the blocking connection.
9355 ** ^(There may be at most one unlock-notify callback registered by a
9356 ** blocked connection. If sqlite3_unlock_notify() is called when the
9357 ** blocked connection already has a registered unlock-notify callback,
9358 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
9359 ** called with a NULL pointer as its second argument, then any existing
9360 ** unlock-notify callback is canceled. ^The blocked connections
9361 ** unlock-notify callback may also be canceled by closing the blocked
9362 ** connection using [sqlite3_close()].
9364 ** The unlock-notify callback is not reentrant. If an application invokes
9365 ** any sqlite3_xxx API functions from within an unlock-notify callback, a
9366 ** crash or deadlock may be the result.
9368 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
9369 ** returns SQLITE_OK.
9371 ** <b>Callback Invocation Details</b>
9373 ** When an unlock-notify callback is registered, the application provides a
9374 ** single void* pointer that is passed to the callback when it is invoked.
9375 ** However, the signature of the callback function allows SQLite to pass
9376 ** it an array of void* context pointers. The first argument passed to
9377 ** an unlock-notify callback is a pointer to an array of void* pointers,
9378 ** and the second is the number of entries in the array.
9380 ** When a blocking connection's transaction is concluded, there may be
9381 ** more than one blocked connection that has registered for an unlock-notify
9382 ** callback. ^If two or more such blocked connections have specified the
9383 ** same callback function, then instead of invoking the callback function
9384 ** multiple times, it is invoked once with the set of void* context pointers
9385 ** specified by the blocked connections bundled together into an array.
9386 ** This gives the application an opportunity to prioritize any actions
9387 ** related to the set of unblocked database connections.
9389 ** <b>Deadlock Detection</b>
9391 ** Assuming that after registering for an unlock-notify callback a
9392 ** database waits for the callback to be issued before taking any further
9393 ** action (a reasonable assumption), then using this API may cause the
9394 ** application to deadlock. For example, if connection X is waiting for
9395 ** connection Y's transaction to be concluded, and similarly connection
9396 ** Y is waiting on connection X's transaction, then neither connection
9397 ** will proceed and the system may remain deadlocked indefinitely.
9399 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
9400 ** detection. ^If a given call to sqlite3_unlock_notify() would put the
9401 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no
9402 ** unlock-notify callback is registered. The system is said to be in
9403 ** a deadlocked state if connection A has registered for an unlock-notify
9404 ** callback on the conclusion of connection B's transaction, and connection
9405 ** B has itself registered for an unlock-notify callback when connection
9406 ** A's transaction is concluded. ^Indirect deadlock is also detected, so
9407 ** the system is also considered to be deadlocked if connection B has
9408 ** registered for an unlock-notify callback on the conclusion of connection
9409 ** C's transaction, where connection C is waiting on connection A. ^Any
9410 ** number of levels of indirection are allowed.
9412 ** <b>The "DROP TABLE" Exception</b>
9414 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
9415 ** always appropriate to call sqlite3_unlock_notify(). There is however,
9416 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
9417 ** SQLite checks if there are any currently executing SELECT statements
9418 ** that belong to the same connection. If there are, SQLITE_LOCKED is
9419 ** returned. In this case there is no "blocking connection", so invoking
9420 ** sqlite3_unlock_notify() results in the unlock-notify callback being
9421 ** invoked immediately. If the application then re-attempts the "DROP TABLE"
9422 ** or "DROP INDEX" query, an infinite loop might be the result.
9424 ** One way around this problem is to check the extended error code returned
9425 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the
9426 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
9427 ** the special "DROP TABLE/INDEX" case, the extended error code is just
9430 SQLITE_API int sqlite3_unlock_notify(
9431 sqlite3 *pBlocked, /* Waiting connection */
9432 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */
9433 void *pNotifyArg /* Argument to pass to xNotify */
9438 ** CAPI3REF: String Comparison
9440 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
9441 ** and extensions to compare the contents of two buffers containing UTF-8
9442 ** strings in a case-independent fashion, using the same definition of "case
9443 ** independence" that SQLite uses internally when comparing identifiers.
9445 SQLITE_API int sqlite3_stricmp(const char *, const char *);
9446 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
9449 ** CAPI3REF: String Globbing
9451 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
9452 ** string X matches the [GLOB] pattern P.
9453 ** ^The definition of [GLOB] pattern matching used in
9454 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
9455 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function
9456 ** is case sensitive.
9458 ** Note that this routine returns zero on a match and non-zero if the strings
9459 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9461 ** See also: [sqlite3_strlike()].
9463 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
9466 ** CAPI3REF: String LIKE Matching
9468 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
9469 ** string X matches the [LIKE] pattern P with escape character E.
9470 ** ^The definition of [LIKE] pattern matching used in
9471 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
9472 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without
9473 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
9474 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
9475 ** insensitive - equivalent upper and lower case ASCII characters match
9478 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
9479 ** only ASCII characters are case folded.
9481 ** Note that this routine returns zero on a match and non-zero if the strings
9482 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9484 ** See also: [sqlite3_strglob()].
9486 SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);
9489 ** CAPI3REF: Error Logging Interface
9491 ** ^The [sqlite3_log()] interface writes a message into the [error log]
9492 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
9493 ** ^If logging is enabled, the zFormat string and subsequent arguments are
9494 ** used with [sqlite3_snprintf()] to generate the final output string.
9496 ** The sqlite3_log() interface is intended for use by extensions such as
9497 ** virtual tables, collating functions, and SQL functions. While there is
9498 ** nothing to prevent an application from calling sqlite3_log(), doing so
9499 ** is considered bad form.
9501 ** The zFormat string must not be NULL.
9503 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine
9504 ** will not use dynamically allocated memory. The log message is stored in
9505 ** a fixed-length buffer on the stack. If the log message is longer than
9506 ** a few hundred characters, it will be truncated to the length of the
9509 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
9512 ** CAPI3REF: Write-Ahead Log Commit Hook
9515 ** ^The [sqlite3_wal_hook()] function is used to register a callback that
9516 ** is invoked each time data is committed to a database in wal mode.
9518 ** ^(The callback is invoked by SQLite after the commit has taken place and
9519 ** the associated write-lock on the database released)^, so the implementation
9520 ** may read, write or [checkpoint] the database as required.
9522 ** ^The first parameter passed to the callback function when it is invoked
9523 ** is a copy of the third parameter passed to sqlite3_wal_hook() when
9524 ** registering the callback. ^The second is a copy of the database handle.
9525 ** ^The third parameter is the name of the database that was written to -
9526 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
9527 ** is the number of pages currently in the write-ahead log file,
9528 ** including those that were just committed.
9530 ** The callback function should normally return [SQLITE_OK]. ^If an error
9531 ** code is returned, that error will propagate back up through the
9532 ** SQLite code base to cause the statement that provoked the callback
9533 ** to report an error, though the commit will have still occurred. If the
9534 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
9535 ** that does not correspond to any valid SQLite error code, the results
9538 ** A single database handle may have at most a single write-ahead log callback
9539 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
9540 ** previously registered write-ahead log callback. ^The return value is
9541 ** a copy of the third parameter from the previous call, if any, or 0.
9542 ** ^Note that the [sqlite3_wal_autocheckpoint()] interface and the
9543 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
9544 ** overwrite any prior [sqlite3_wal_hook()] settings.
9546 SQLITE_API void *sqlite3_wal_hook(
9548 int(*)(void *,sqlite3*,const char*,int),
9553 ** CAPI3REF: Configure an auto-checkpoint
9556 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
9557 ** [sqlite3_wal_hook()] that causes any database on [database connection] D
9558 ** to automatically [checkpoint]
9559 ** after committing a transaction if there are N or
9560 ** more frames in the [write-ahead log] file. ^Passing zero or
9561 ** a negative value as the nFrame parameter disables automatic
9562 ** checkpoints entirely.
9564 ** ^The callback registered by this function replaces any existing callback
9565 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
9566 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
9567 ** configured by this function.
9569 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
9572 ** ^Checkpoints initiated by this mechanism are
9573 ** [sqlite3_wal_checkpoint_v2|PASSIVE].
9575 ** ^Every new [database connection] defaults to having the auto-checkpoint
9576 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
9577 ** pages. The use of this interface
9578 ** is only necessary if the default setting is found to be suboptimal
9579 ** for a particular application.
9581 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
9584 ** CAPI3REF: Checkpoint a database
9587 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
9588 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
9590 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the
9591 ** [write-ahead log] for database X on [database connection] D to be
9592 ** transferred into the database file and for the write-ahead log to
9593 ** be reset. See the [checkpointing] documentation for addition
9596 ** This interface used to be the only way to cause a checkpoint to
9597 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
9598 ** interface was added. This interface is retained for backwards
9599 ** compatibility and as a convenience for applications that need to manually
9600 ** start a callback but which do not need the full power (and corresponding
9601 ** complication) of [sqlite3_wal_checkpoint_v2()].
9603 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
9606 ** CAPI3REF: Checkpoint a database
9609 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
9610 ** operation on database X of [database connection] D in mode M. Status
9611 ** information is written back into integers pointed to by L and C.)^
9612 ** ^(The M parameter must be a valid [checkpoint mode]:)^
9615 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
9616 ** ^Checkpoint as many frames as possible without waiting for any database
9617 ** readers or writers to finish, then sync the database file if all frames
9618 ** in the log were checkpointed. ^The [busy-handler callback]
9619 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.
9620 ** ^On the other hand, passive mode might leave the checkpoint unfinished
9621 ** if there are concurrent readers or writers.
9623 ** <dt>SQLITE_CHECKPOINT_FULL<dd>
9624 ** ^This mode blocks (it invokes the
9625 ** [sqlite3_busy_handler|busy-handler callback]) until there is no
9626 ** database writer and all readers are reading from the most recent database
9627 ** snapshot. ^It then checkpoints all frames in the log file and syncs the
9628 ** database file. ^This mode blocks new database writers while it is pending,
9629 ** but new database readers are allowed to continue unimpeded.
9631 ** <dt>SQLITE_CHECKPOINT_RESTART<dd>
9632 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
9633 ** that after checkpointing the log file it blocks (calls the
9634 ** [busy-handler callback])
9635 ** until all readers are reading from the database file only. ^This ensures
9636 ** that the next writer will restart the log file from the beginning.
9637 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
9638 ** database writer attempts while it is pending, but does not impede readers.
9640 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
9641 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
9642 ** addition that it also truncates the log file to zero bytes just prior
9643 ** to a successful return.
9646 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
9647 ** the log file or to -1 if the checkpoint could not run because
9648 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
9649 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
9650 ** log file (including any that were already checkpointed before the function
9651 ** was called) or to -1 if the checkpoint could not run due to an error or
9652 ** because the database is not in WAL mode. ^Note that upon successful
9653 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
9654 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
9656 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
9657 ** any other process is running a checkpoint operation at the same time, the
9658 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a
9659 ** busy-handler configured, it will not be invoked in this case.
9661 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the
9662 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be
9663 ** obtained immediately, and a busy-handler is configured, it is invoked and
9664 ** the writer lock retried until either the busy-handler returns 0 or the lock
9665 ** is successfully obtained. ^The busy-handler is also invoked while waiting for
9666 ** database readers as described above. ^If the busy-handler returns 0 before
9667 ** the writer lock is obtained or while waiting for database readers, the
9668 ** checkpoint operation proceeds from that point in the same way as
9669 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
9670 ** without blocking any further. ^SQLITE_BUSY is returned in this case.
9672 ** ^If parameter zDb is NULL or points to a zero length string, then the
9673 ** specified operation is attempted on all WAL databases [attached] to
9674 ** [database connection] db. In this case the
9675 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If
9676 ** an SQLITE_BUSY error is encountered when processing one or more of the
9677 ** attached WAL databases, the operation is still attempted on any remaining
9678 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other
9679 ** error occurs while processing an attached database, processing is abandoned
9680 ** and the error code is returned to the caller immediately. ^If no error
9681 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached
9682 ** databases, SQLITE_OK is returned.
9684 ** ^If database zDb is the name of an attached database that is not in WAL
9685 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
9686 ** zDb is not NULL (or a zero length string) and is not the name of any
9687 ** attached database, SQLITE_ERROR is returned to the caller.
9689 ** ^Unless it returns SQLITE_MISUSE,
9690 ** the sqlite3_wal_checkpoint_v2() interface
9691 ** sets the error information that is queried by
9692 ** [sqlite3_errcode()] and [sqlite3_errmsg()].
9694 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
9697 SQLITE_API int sqlite3_wal_checkpoint_v2(
9698 sqlite3 *db, /* Database handle */
9699 const char *zDb, /* Name of attached database (or NULL) */
9700 int eMode, /* SQLITE_CHECKPOINT_* value */
9701 int *pnLog, /* OUT: Size of WAL log in frames */
9702 int *pnCkpt /* OUT: Total number of frames checkpointed */
9706 ** CAPI3REF: Checkpoint Mode Values
9707 ** KEYWORDS: {checkpoint mode}
9709 ** These constants define all valid values for the "checkpoint mode" passed
9710 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
9711 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
9712 ** meaning of each of these checkpoint modes.
9714 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */
9715 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */
9716 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for readers */
9717 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */
9720 ** CAPI3REF: Virtual Table Interface Configuration
9722 ** This function may be called by either the [xConnect] or [xCreate] method
9723 ** of a [virtual table] implementation to configure
9724 ** various facets of the virtual table interface.
9726 ** If this interface is invoked outside the context of an xConnect or
9727 ** xCreate virtual table method then the behavior is undefined.
9729 ** In the call sqlite3_vtab_config(D,C,...) the D parameter is the
9730 ** [database connection] in which the virtual table is being created and
9731 ** which is passed in as the first argument to the [xConnect] or [xCreate]
9732 ** method that is invoking sqlite3_vtab_config(). The C parameter is one
9733 ** of the [virtual table configuration options]. The presence and meaning
9734 ** of parameters after C depend on which [virtual table configuration option]
9737 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
9740 ** CAPI3REF: Virtual Table Configuration Options
9741 ** KEYWORDS: {virtual table configuration options}
9742 ** KEYWORDS: {virtual table configuration option}
9744 ** These macros define the various options to the
9745 ** [sqlite3_vtab_config()] interface that [virtual table] implementations
9746 ** can use to customize and optimize their behavior.
9749 ** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]]
9750 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt>
9751 ** <dd>Calls of the form
9752 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
9753 ** where X is an integer. If X is zero, then the [virtual table] whose
9754 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
9755 ** support constraints. In this configuration (which is the default) if
9756 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
9757 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
9758 ** specified as part of the users SQL statement, regardless of the actual
9759 ** ON CONFLICT mode specified.
9761 ** If X is non-zero, then the virtual table implementation guarantees
9762 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
9763 ** any modifications to internal or persistent data structures have been made.
9764 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
9765 ** is able to roll back a statement or database transaction, and abandon
9766 ** or continue processing the current SQL statement as appropriate.
9767 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
9768 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
9771 ** Virtual table implementations that are required to handle OR REPLACE
9772 ** must do so within the [xUpdate] method. If a call to the
9773 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON
9774 ** CONFLICT policy is REPLACE, the virtual table implementation should
9775 ** silently replace the appropriate rows within the xUpdate callback and
9776 ** return SQLITE_OK. Or, if this is not possible, it may return
9777 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
9778 ** constraint handling.
9781 ** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt>
9782 ** <dd>Calls of the form
9783 ** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the
9784 ** the [xConnect] or [xCreate] methods of a [virtual table] implementation
9785 ** prohibits that virtual table from being used from within triggers and
9789 ** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt>
9790 ** <dd>Calls of the form
9791 ** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the
9792 ** the [xConnect] or [xCreate] methods of a [virtual table] implementation
9793 ** identify that virtual table as being safe to use from within triggers
9794 ** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the
9795 ** virtual table can do no serious harm even if it is controlled by a
9796 ** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS
9797 ** flag unless absolutely necessary.
9800 ** [[SQLITE_VTAB_USES_ALL_SCHEMAS]]<dt>SQLITE_VTAB_USES_ALL_SCHEMAS</dt>
9801 ** <dd>Calls of the form
9802 ** [sqlite3_vtab_config](db,SQLITE_VTAB_USES_ALL_SCHEMA) from within the
9803 ** the [xConnect] or [xCreate] methods of a [virtual table] implementation
9804 ** instruct the query planner to begin at least a read transaction on
9805 ** all schemas ("main", "temp", and any ATTACH-ed databases) whenever the
9806 ** virtual table is used.
9810 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
9811 #define SQLITE_VTAB_INNOCUOUS 2
9812 #define SQLITE_VTAB_DIRECTONLY 3
9813 #define SQLITE_VTAB_USES_ALL_SCHEMAS 4
9816 ** CAPI3REF: Determine The Virtual Table Conflict Policy
9818 ** This function may only be called from within a call to the [xUpdate] method
9819 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
9820 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
9821 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
9822 ** of the SQL statement that triggered the call to the [xUpdate] method of the
9825 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
9828 ** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE
9830 ** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn]
9831 ** method of a [virtual table], then it might return true if the
9832 ** column is being fetched as part of an UPDATE operation during which the
9833 ** column value will not change. The virtual table implementation can use
9834 ** this hint as permission to substitute a return value that is less
9835 ** expensive to compute and that the corresponding
9836 ** [xUpdate] method understands as a "no-change" value.
9838 ** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that
9839 ** the column is not changed by the UPDATE statement, then the xColumn
9840 ** method can optionally return without setting a result, without calling
9841 ** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces].
9842 ** In that case, [sqlite3_value_nochange(X)] will return true for the
9843 ** same column in the [xUpdate] method.
9845 ** The sqlite3_vtab_nochange() routine is an optimization. Virtual table
9846 ** implementations should continue to give a correct answer even if the
9847 ** sqlite3_vtab_nochange() interface were to always return false. In the
9848 ** current implementation, the sqlite3_vtab_nochange() interface does always
9849 ** returns false for the enhanced [UPDATE FROM] statement.
9851 SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*);
9854 ** CAPI3REF: Determine The Collation For a Virtual Table Constraint
9855 ** METHOD: sqlite3_index_info
9857 ** This function may only be called from within a call to the [xBestIndex]
9858 ** method of a [virtual table]. This function returns a pointer to a string
9859 ** that is the name of the appropriate collation sequence to use for text
9860 ** comparisons on the constraint identified by its arguments.
9862 ** The first argument must be the pointer to the [sqlite3_index_info] object
9863 ** that is the first parameter to the xBestIndex() method. The second argument
9864 ** must be an index into the aConstraint[] array belonging to the
9865 ** sqlite3_index_info structure passed to xBestIndex.
9868 ** The first parameter must be the same pointer that is passed into the
9869 ** xBestMethod() method. The first parameter may not be a pointer to a
9870 ** different [sqlite3_index_info] object, even an exact copy.
9872 ** The return value is computed as follows:
9875 ** <li><p> If the constraint comes from a WHERE clause expression that contains
9876 ** a [COLLATE operator], then the name of the collation specified by
9877 ** that COLLATE operator is returned.
9878 ** <li><p> If there is no COLLATE operator, but the column that is the subject
9879 ** of the constraint specifies an alternative collating sequence via
9880 ** a [COLLATE clause] on the column definition within the CREATE TABLE
9881 ** statement that was passed into [sqlite3_declare_vtab()], then the
9882 ** name of that alternative collating sequence is returned.
9883 ** <li><p> Otherwise, "BINARY" is returned.
9886 SQLITE_API const char *sqlite3_vtab_collation(sqlite3_index_info*,int);
9889 ** CAPI3REF: Determine if a virtual table query is DISTINCT
9890 ** METHOD: sqlite3_index_info
9892 ** This API may only be used from within an [xBestIndex|xBestIndex method]
9893 ** of a [virtual table] implementation. The result of calling this
9894 ** interface from outside of xBestIndex() is undefined and probably harmful.
9896 ** ^The sqlite3_vtab_distinct() interface returns an integer between 0 and
9897 ** 3. The integer returned by sqlite3_vtab_distinct()
9898 ** gives the virtual table additional information about how the query
9899 ** planner wants the output to be ordered. As long as the virtual table
9900 ** can meet the ordering requirements of the query planner, it may set
9901 ** the "orderByConsumed" flag.
9903 ** <ol><li value="0"><p>
9904 ** ^If the sqlite3_vtab_distinct() interface returns 0, that means
9905 ** that the query planner needs the virtual table to return all rows in the
9906 ** sort order defined by the "nOrderBy" and "aOrderBy" fields of the
9907 ** [sqlite3_index_info] object. This is the default expectation. If the
9908 ** virtual table outputs all rows in sorted order, then it is always safe for
9909 ** the xBestIndex method to set the "orderByConsumed" flag, regardless of
9910 ** the return value from sqlite3_vtab_distinct().
9911 ** <li value="1"><p>
9912 ** ^(If the sqlite3_vtab_distinct() interface returns 1, that means
9913 ** that the query planner does not need the rows to be returned in sorted order
9914 ** as long as all rows with the same values in all columns identified by the
9915 ** "aOrderBy" field are adjacent.)^ This mode is used when the query planner
9916 ** is doing a GROUP BY.
9917 ** <li value="2"><p>
9918 ** ^(If the sqlite3_vtab_distinct() interface returns 2, that means
9919 ** that the query planner does not need the rows returned in any particular
9920 ** order, as long as rows with the same values in all "aOrderBy" columns
9921 ** are adjacent.)^ ^(Furthermore, only a single row for each particular
9922 ** combination of values in the columns identified by the "aOrderBy" field
9923 ** needs to be returned.)^ ^It is always ok for two or more rows with the same
9924 ** values in all "aOrderBy" columns to be returned, as long as all such rows
9925 ** are adjacent. ^The virtual table may, if it chooses, omit extra rows
9926 ** that have the same value for all columns identified by "aOrderBy".
9927 ** ^However omitting the extra rows is optional.
9928 ** This mode is used for a DISTINCT query.
9929 ** <li value="3"><p>
9930 ** ^(If the sqlite3_vtab_distinct() interface returns 3, that means
9931 ** that the query planner needs only distinct rows but it does need the
9932 ** rows to be sorted.)^ ^The virtual table implementation is free to omit
9933 ** rows that are identical in all aOrderBy columns, if it wants to, but
9934 ** it is not required to omit any rows. This mode is used for queries
9935 ** that have both DISTINCT and ORDER BY clauses.
9938 ** ^For the purposes of comparing virtual table output values to see if the
9939 ** values are same value for sorting purposes, two NULL values are considered
9940 ** to be the same. In other words, the comparison operator is "IS"
9941 ** (or "IS NOT DISTINCT FROM") and not "==".
9943 ** If a virtual table implementation is unable to meet the requirements
9944 ** specified above, then it must not set the "orderByConsumed" flag in the
9945 ** [sqlite3_index_info] object or an incorrect answer may result.
9947 ** ^A virtual table implementation is always free to return rows in any order
9948 ** it wants, as long as the "orderByConsumed" flag is not set. ^When the
9949 ** the "orderByConsumed" flag is unset, the query planner will add extra
9950 ** [bytecode] to ensure that the final results returned by the SQL query are
9951 ** ordered correctly. The use of the "orderByConsumed" flag and the
9952 ** sqlite3_vtab_distinct() interface is merely an optimization. ^Careful
9953 ** use of the sqlite3_vtab_distinct() interface and the "orderByConsumed"
9954 ** flag might help queries against a virtual table to run faster. Being
9955 ** overly aggressive and setting the "orderByConsumed" flag when it is not
9956 ** valid to do so, on the other hand, might cause SQLite to return incorrect
9959 SQLITE_API int sqlite3_vtab_distinct(sqlite3_index_info*);
9962 ** CAPI3REF: Identify and handle IN constraints in xBestIndex
9964 ** This interface may only be used from within an
9965 ** [xBestIndex|xBestIndex() method] of a [virtual table] implementation.
9966 ** The result of invoking this interface from any other context is
9967 ** undefined and probably harmful.
9969 ** ^(A constraint on a virtual table of the form
9970 ** "[IN operator|column IN (...)]" is
9971 ** communicated to the xBestIndex method as a
9972 ** [SQLITE_INDEX_CONSTRAINT_EQ] constraint.)^ If xBestIndex wants to use
9973 ** this constraint, it must set the corresponding
9974 ** aConstraintUsage[].argvIndex to a positive integer. ^(Then, under
9975 ** the usual mode of handling IN operators, SQLite generates [bytecode]
9976 ** that invokes the [xFilter|xFilter() method] once for each value
9977 ** on the right-hand side of the IN operator.)^ Thus the virtual table
9978 ** only sees a single value from the right-hand side of the IN operator
9981 ** In some cases, however, it would be advantageous for the virtual
9982 ** table to see all values on the right-hand of the IN operator all at
9983 ** once. The sqlite3_vtab_in() interfaces facilitates this in two ways:
9987 ** ^A call to sqlite3_vtab_in(P,N,-1) will return true (non-zero)
9988 ** if and only if the [sqlite3_index_info|P->aConstraint][N] constraint
9989 ** is an [IN operator] that can be processed all at once. ^In other words,
9990 ** sqlite3_vtab_in() with -1 in the third argument is a mechanism
9991 ** by which the virtual table can ask SQLite if all-at-once processing
9992 ** of the IN operator is even possible.
9995 ** ^A call to sqlite3_vtab_in(P,N,F) with F==1 or F==0 indicates
9996 ** to SQLite that the virtual table does or does not want to process
9997 ** the IN operator all-at-once, respectively. ^Thus when the third
9998 ** parameter (F) is non-negative, this interface is the mechanism by
9999 ** which the virtual table tells SQLite how it wants to process the
10003 ** ^The sqlite3_vtab_in(P,N,F) interface can be invoked multiple times
10004 ** within the same xBestIndex method call. ^For any given P,N pair,
10005 ** the return value from sqlite3_vtab_in(P,N,F) will always be the same
10006 ** within the same xBestIndex call. ^If the interface returns true
10007 ** (non-zero), that means that the constraint is an IN operator
10008 ** that can be processed all-at-once. ^If the constraint is not an IN
10009 ** operator or cannot be processed all-at-once, then the interface returns
10012 ** ^(All-at-once processing of the IN operator is selected if both of the
10013 ** following conditions are met:
10016 ** <li><p> The P->aConstraintUsage[N].argvIndex value is set to a positive
10017 ** integer. This is how the virtual table tells SQLite that it wants to
10018 ** use the N-th constraint.
10020 ** <li><p> The last call to sqlite3_vtab_in(P,N,F) for which F was
10021 ** non-negative had F>=1.
10024 ** ^If either or both of the conditions above are false, then SQLite uses
10025 ** the traditional one-at-a-time processing strategy for the IN constraint.
10026 ** ^If both conditions are true, then the argvIndex-th parameter to the
10027 ** xFilter method will be an [sqlite3_value] that appears to be NULL,
10028 ** but which can be passed to [sqlite3_vtab_in_first()] and
10029 ** [sqlite3_vtab_in_next()] to find all values on the right-hand side
10030 ** of the IN constraint.
10032 SQLITE_API int sqlite3_vtab_in(sqlite3_index_info*, int iCons, int bHandle);
10035 ** CAPI3REF: Find all elements on the right-hand side of an IN constraint.
10037 ** These interfaces are only useful from within the
10038 ** [xFilter|xFilter() method] of a [virtual table] implementation.
10039 ** The result of invoking these interfaces from any other context
10040 ** is undefined and probably harmful.
10042 ** The X parameter in a call to sqlite3_vtab_in_first(X,P) or
10043 ** sqlite3_vtab_in_next(X,P) should be one of the parameters to the
10044 ** xFilter method which invokes these routines, and specifically
10045 ** a parameter that was previously selected for all-at-once IN constraint
10046 ** processing use the [sqlite3_vtab_in()] interface in the
10047 ** [xBestIndex|xBestIndex method]. ^(If the X parameter is not
10048 ** an xFilter argument that was selected for all-at-once IN constraint
10049 ** processing, then these routines return [SQLITE_ERROR].)^
10051 ** ^(Use these routines to access all values on the right-hand side
10052 ** of the IN constraint using code like the following:
10054 ** <blockquote><pre>
10055 ** for(rc=sqlite3_vtab_in_first(pList, &pVal);
10056 ** rc==SQLITE_OK && pVal;
10057 ** rc=sqlite3_vtab_in_next(pList, &pVal)
10059 ** // do something with pVal
10061 ** if( rc!=SQLITE_OK ){
10062 ** // an error has occurred
10064 ** </pre></blockquote>)^
10066 ** ^On success, the sqlite3_vtab_in_first(X,P) and sqlite3_vtab_in_next(X,P)
10067 ** routines return SQLITE_OK and set *P to point to the first or next value
10068 ** on the RHS of the IN constraint. ^If there are no more values on the
10069 ** right hand side of the IN constraint, then *P is set to NULL and these
10070 ** routines return [SQLITE_DONE]. ^The return value might be
10071 ** some other value, such as SQLITE_NOMEM, in the event of a malfunction.
10073 ** The *ppOut values returned by these routines are only valid until the
10074 ** next call to either of these routines or until the end of the xFilter
10075 ** method from which these routines were called. If the virtual table
10076 ** implementation needs to retain the *ppOut values for longer, it must make
10077 ** copies. The *ppOut values are [protected sqlite3_value|protected].
10079 SQLITE_API int sqlite3_vtab_in_first(sqlite3_value *pVal, sqlite3_value **ppOut);
10080 SQLITE_API int sqlite3_vtab_in_next(sqlite3_value *pVal, sqlite3_value **ppOut);
10083 ** CAPI3REF: Constraint values in xBestIndex()
10084 ** METHOD: sqlite3_index_info
10086 ** This API may only be used from within the [xBestIndex|xBestIndex method]
10087 ** of a [virtual table] implementation. The result of calling this interface
10088 ** from outside of an xBestIndex method are undefined and probably harmful.
10090 ** ^When the sqlite3_vtab_rhs_value(P,J,V) interface is invoked from within
10091 ** the [xBestIndex] method of a [virtual table] implementation, with P being
10092 ** a copy of the [sqlite3_index_info] object pointer passed into xBestIndex and
10093 ** J being a 0-based index into P->aConstraint[], then this routine
10094 ** attempts to set *V to the value of the right-hand operand of
10095 ** that constraint if the right-hand operand is known. ^If the
10096 ** right-hand operand is not known, then *V is set to a NULL pointer.
10097 ** ^The sqlite3_vtab_rhs_value(P,J,V) interface returns SQLITE_OK if
10098 ** and only if *V is set to a value. ^The sqlite3_vtab_rhs_value(P,J,V)
10099 ** inteface returns SQLITE_NOTFOUND if the right-hand side of the J-th
10100 ** constraint is not available. ^The sqlite3_vtab_rhs_value() interface
10101 ** can return an result code other than SQLITE_OK or SQLITE_NOTFOUND if
10102 ** something goes wrong.
10104 ** The sqlite3_vtab_rhs_value() interface is usually only successful if
10105 ** the right-hand operand of a constraint is a literal value in the original
10106 ** SQL statement. If the right-hand operand is an expression or a reference
10107 ** to some other column or a [host parameter], then sqlite3_vtab_rhs_value()
10108 ** will probably return [SQLITE_NOTFOUND].
10110 ** ^(Some constraints, such as [SQLITE_INDEX_CONSTRAINT_ISNULL] and
10111 ** [SQLITE_INDEX_CONSTRAINT_ISNOTNULL], have no right-hand operand. For such
10112 ** constraints, sqlite3_vtab_rhs_value() always returns SQLITE_NOTFOUND.)^
10114 ** ^The [sqlite3_value] object returned in *V is a protected sqlite3_value
10115 ** and remains valid for the duration of the xBestIndex method call.
10116 ** ^When xBestIndex returns, the sqlite3_value object returned by
10117 ** sqlite3_vtab_rhs_value() is automatically deallocated.
10119 ** The "_rhs_" in the name of this routine is an abbreviation for
10120 ** "Right-Hand Side".
10122 SQLITE_API int sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal);
10125 ** CAPI3REF: Conflict resolution modes
10126 ** KEYWORDS: {conflict resolution mode}
10128 ** These constants are returned by [sqlite3_vtab_on_conflict()] to
10129 ** inform a [virtual table] implementation what the [ON CONFLICT] mode
10130 ** is for the SQL statement being evaluated.
10132 ** Note that the [SQLITE_IGNORE] constant is also used as a potential
10133 ** return value from the [sqlite3_set_authorizer()] callback and that
10134 ** [SQLITE_ABORT] is also a [result code].
10136 #define SQLITE_ROLLBACK 1
10137 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
10138 #define SQLITE_FAIL 3
10139 /* #define SQLITE_ABORT 4 // Also an error code */
10140 #define SQLITE_REPLACE 5
10143 ** CAPI3REF: Prepared Statement Scan Status Opcodes
10144 ** KEYWORDS: {scanstatus options}
10146 ** The following constants can be used for the T parameter to the
10147 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a
10148 ** different metric for sqlite3_stmt_scanstatus() to return.
10150 ** When the value returned to V is a string, space to hold that string is
10151 ** managed by the prepared statement S and will be automatically freed when
10154 ** Not all values are available for all query elements. When a value is
10155 ** not available, the output variable is set to -1 if the value is numeric,
10156 ** or to NULL if it is a string (SQLITE_SCANSTAT_NAME).
10159 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
10160 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be
10161 ** set to the total number of times that the X-th loop has run.</dd>
10163 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
10164 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set
10165 ** to the total number of rows examined by all iterations of the X-th loop.</dd>
10167 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
10168 ** <dd>^The "double" variable pointed to by the V parameter will be set to the
10169 ** query planner's estimate for the average number of rows output from each
10170 ** iteration of the X-th loop. If the query planner's estimates was accurate,
10171 ** then this value will approximate the quotient NVISIT/NLOOP and the
10172 ** product of this value for all prior loops with the same SELECTID will
10173 ** be the NLOOP value for the current loop.
10175 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
10176 ** <dd>^The "const char *" variable pointed to by the V parameter will be set
10177 ** to a zero-terminated UTF-8 string containing the name of the index or table
10178 ** used for the X-th loop.
10180 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
10181 ** <dd>^The "const char *" variable pointed to by the V parameter will be set
10182 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
10183 ** description for the X-th loop.
10185 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECTID</dt>
10186 ** <dd>^The "int" variable pointed to by the V parameter will be set to the
10187 ** id for the X-th query plan element. The id value is unique within the
10188 ** statement. The select-id is the same value as is output in the first
10189 ** column of an [EXPLAIN QUERY PLAN] query.
10191 ** [[SQLITE_SCANSTAT_PARENTID]] <dt>SQLITE_SCANSTAT_PARENTID</dt>
10192 ** <dd>The "int" variable pointed to by the V parameter will be set to the
10193 ** the id of the parent of the current query element, if applicable, or
10194 ** to zero if the query element has no parent. This is the same value as
10195 ** returned in the second column of an [EXPLAIN QUERY PLAN] query.
10197 ** [[SQLITE_SCANSTAT_NCYCLE]] <dt>SQLITE_SCANSTAT_NCYCLE</dt>
10198 ** <dd>The sqlite3_int64 output value is set to the number of cycles,
10199 ** according to the processor time-stamp counter, that elapsed while the
10200 ** query element was being processed. This value is not available for
10201 ** all query elements - if it is unavailable the output variable is
10205 #define SQLITE_SCANSTAT_NLOOP 0
10206 #define SQLITE_SCANSTAT_NVISIT 1
10207 #define SQLITE_SCANSTAT_EST 2
10208 #define SQLITE_SCANSTAT_NAME 3
10209 #define SQLITE_SCANSTAT_EXPLAIN 4
10210 #define SQLITE_SCANSTAT_SELECTID 5
10211 #define SQLITE_SCANSTAT_PARENTID 6
10212 #define SQLITE_SCANSTAT_NCYCLE 7
10215 ** CAPI3REF: Prepared Statement Scan Status
10216 ** METHOD: sqlite3_stmt
10218 ** These interfaces return information about the predicted and measured
10219 ** performance for pStmt. Advanced applications can use this
10220 ** interface to compare the predicted and the measured performance and
10221 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
10223 ** Since this interface is expected to be rarely used, it is only
10224 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
10225 ** compile-time option.
10227 ** The "iScanStatusOp" parameter determines which status information to return.
10228 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
10229 ** of this interface is undefined. ^The requested measurement is written into
10230 ** a variable pointed to by the "pOut" parameter.
10232 ** The "flags" parameter must be passed a mask of flags. At present only
10233 ** one flag is defined - SQLITE_SCANSTAT_COMPLEX. If SQLITE_SCANSTAT_COMPLEX
10234 ** is specified, then status information is available for all elements
10235 ** of a query plan that are reported by "EXPLAIN QUERY PLAN" output. If
10236 ** SQLITE_SCANSTAT_COMPLEX is not specified, then only query plan elements
10237 ** that correspond to query loops (the "SCAN..." and "SEARCH..." elements of
10238 ** the EXPLAIN QUERY PLAN output) are available. Invoking API
10239 ** sqlite3_stmt_scanstatus() is equivalent to calling
10240 ** sqlite3_stmt_scanstatus_v2() with a zeroed flags parameter.
10242 ** Parameter "idx" identifies the specific query element to retrieve statistics
10243 ** for. Query elements are numbered starting from zero. A value of -1 may be
10244 ** to query for statistics regarding the entire query. ^If idx is out of range
10245 ** - less than -1 or greater than or equal to the total number of query
10246 ** elements used to implement the statement - a non-zero value is returned and
10247 ** the variable that pOut points to is unchanged.
10249 ** See also: [sqlite3_stmt_scanstatus_reset()]
10251 SQLITE_API int sqlite3_stmt_scanstatus(
10252 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
10253 int idx, /* Index of loop to report on */
10254 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
10255 void *pOut /* Result written here */
10257 SQLITE_API int sqlite3_stmt_scanstatus_v2(
10258 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
10259 int idx, /* Index of loop to report on */
10260 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
10261 int flags, /* Mask of flags defined below */
10262 void *pOut /* Result written here */
10266 ** CAPI3REF: Prepared Statement Scan Status
10267 ** KEYWORDS: {scan status flags}
10269 #define SQLITE_SCANSTAT_COMPLEX 0x0001
10272 ** CAPI3REF: Zero Scan-Status Counters
10273 ** METHOD: sqlite3_stmt
10275 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
10277 ** This API is only available if the library is built with pre-processor
10278 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
10280 SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
10283 ** CAPI3REF: Flush caches to disk mid-transaction
10286 ** ^If a write-transaction is open on [database connection] D when the
10287 ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty
10288 ** pages in the pager-cache that are not currently in use are written out
10289 ** to disk. A dirty page may be in use if a database cursor created by an
10290 ** active SQL statement is reading from it, or if it is page 1 of a database
10291 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)]
10292 ** interface flushes caches for all schemas - "main", "temp", and
10293 ** any [attached] databases.
10295 ** ^If this function needs to obtain extra database locks before dirty pages
10296 ** can be flushed to disk, it does so. ^If those locks cannot be obtained
10297 ** immediately and there is a busy-handler callback configured, it is invoked
10298 ** in the usual manner. ^If the required lock still cannot be obtained, then
10299 ** the database is skipped and an attempt made to flush any dirty pages
10300 ** belonging to the next (if any) database. ^If any databases are skipped
10301 ** because locks cannot be obtained, but no other error occurs, this
10302 ** function returns SQLITE_BUSY.
10304 ** ^If any other error occurs while flushing dirty pages to disk (for
10305 ** example an IO error or out-of-memory condition), then processing is
10306 ** abandoned and an SQLite [error code] is returned to the caller immediately.
10308 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
10310 ** ^This function does not set the database handle error code or message
10311 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
10313 SQLITE_API int sqlite3_db_cacheflush(sqlite3*);
10316 ** CAPI3REF: The pre-update hook.
10319 ** ^These interfaces are only available if SQLite is compiled using the
10320 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
10322 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function
10323 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation
10324 ** on a database table.
10325 ** ^At most one preupdate hook may be registered at a time on a single
10326 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
10327 ** the previous setting.
10328 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
10329 ** with a NULL pointer as the second parameter.
10330 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
10331 ** the first parameter to callbacks.
10333 ** ^The preupdate hook only fires for changes to real database tables; the
10334 ** preupdate hook is not invoked for changes to [virtual tables] or to
10335 ** system tables like sqlite_sequence or sqlite_stat1.
10337 ** ^The second parameter to the preupdate callback is a pointer to
10338 ** the [database connection] that registered the preupdate hook.
10339 ** ^The third parameter to the preupdate callback is one of the constants
10340 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the
10341 ** kind of update operation that is about to occur.
10342 ** ^(The fourth parameter to the preupdate callback is the name of the
10343 ** database within the database connection that is being modified. This
10344 ** will be "main" for the main database or "temp" for TEMP tables or
10345 ** the name given after the AS keyword in the [ATTACH] statement for attached
10347 ** ^The fifth parameter to the preupdate callback is the name of the
10348 ** table that is being modified.
10350 ** For an UPDATE or DELETE operation on a [rowid table], the sixth
10351 ** parameter passed to the preupdate callback is the initial [rowid] of the
10352 ** row being modified or deleted. For an INSERT operation on a rowid table,
10353 ** or any operation on a WITHOUT ROWID table, the value of the sixth
10354 ** parameter is undefined. For an INSERT or UPDATE on a rowid table the
10355 ** seventh parameter is the final rowid value of the row being inserted
10356 ** or updated. The value of the seventh parameter passed to the callback
10357 ** function is not defined for operations on WITHOUT ROWID tables, or for
10358 ** DELETE operations on rowid tables.
10360 ** ^The sqlite3_preupdate_hook(D,C,P) function returns the P argument from
10361 ** the previous call on the same [database connection] D, or NULL for
10362 ** the first call on D.
10364 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
10365 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
10366 ** provide additional information about a preupdate event. These routines
10367 ** may only be called from within a preupdate callback. Invoking any of
10368 ** these routines from outside of a preupdate callback or with a
10369 ** [database connection] pointer that is different from the one supplied
10370 ** to the preupdate callback results in undefined and probably undesirable
10373 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
10374 ** in the row that is being inserted, updated, or deleted.
10376 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
10377 ** a [protected sqlite3_value] that contains the value of the Nth column of
10378 ** the table row before it is updated. The N parameter must be between 0
10379 ** and one less than the number of columns or the behavior will be
10380 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
10381 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
10382 ** behavior is undefined. The [sqlite3_value] that P points to
10383 ** will be destroyed when the preupdate callback returns.
10385 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
10386 ** a [protected sqlite3_value] that contains the value of the Nth column of
10387 ** the table row after it is updated. The N parameter must be between 0
10388 ** and one less than the number of columns or the behavior will be
10389 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
10390 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
10391 ** behavior is undefined. The [sqlite3_value] that P points to
10392 ** will be destroyed when the preupdate callback returns.
10394 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
10395 ** callback was invoked as a result of a direct insert, update, or delete
10396 ** operation; or 1 for inserts, updates, or deletes invoked by top-level
10397 ** triggers; or 2 for changes resulting from triggers called by top-level
10398 ** triggers; and so forth.
10400 ** When the [sqlite3_blob_write()] API is used to update a blob column,
10401 ** the pre-update hook is invoked with SQLITE_DELETE. This is because the
10402 ** in this case the new values are not available. In this case, when a
10403 ** callback made with op==SQLITE_DELETE is actually a write using the
10404 ** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns
10405 ** the index of the column being written. In other cases, where the
10406 ** pre-update hook is being invoked for some other reason, including a
10407 ** regular DELETE, sqlite3_preupdate_blobwrite() returns -1.
10409 ** See also: [sqlite3_update_hook()]
10411 #if defined(SQLITE_ENABLE_PREUPDATE_HOOK)
10412 SQLITE_API void *sqlite3_preupdate_hook(
10415 void *pCtx, /* Copy of third arg to preupdate_hook() */
10416 sqlite3 *db, /* Database handle */
10417 int op, /* SQLITE_UPDATE, DELETE or INSERT */
10418 char const *zDb, /* Database name */
10419 char const *zName, /* Table name */
10420 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */
10421 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */
10425 SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
10426 SQLITE_API int sqlite3_preupdate_count(sqlite3 *);
10427 SQLITE_API int sqlite3_preupdate_depth(sqlite3 *);
10428 SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);
10429 SQLITE_API int sqlite3_preupdate_blobwrite(sqlite3 *);
10433 ** CAPI3REF: Low-level system error code
10436 ** ^Attempt to return the underlying operating system error code or error
10437 ** number that caused the most recent I/O error or failure to open a file.
10438 ** The return value is OS-dependent. For example, on unix systems, after
10439 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be
10440 ** called to get back the underlying "errno" that caused the problem, such
10441 ** as ENOSPC, EAUTH, EISDIR, and so forth.
10443 SQLITE_API int sqlite3_system_errno(sqlite3*);
10446 ** CAPI3REF: Database Snapshot
10447 ** KEYWORDS: {snapshot} {sqlite3_snapshot}
10449 ** An instance of the snapshot object records the state of a [WAL mode]
10450 ** database for some specific point in history.
10452 ** In [WAL mode], multiple [database connections] that are open on the
10453 ** same database file can each be reading a different historical version
10454 ** of the database file. When a [database connection] begins a read
10455 ** transaction, that connection sees an unchanging copy of the database
10456 ** as it existed for the point in time when the transaction first started.
10457 ** Subsequent changes to the database from other connections are not seen
10458 ** by the reader until a new read transaction is started.
10460 ** The sqlite3_snapshot object records state information about an historical
10461 ** version of the database file so that it is possible to later open a new read
10462 ** transaction that sees that historical version of the database rather than
10463 ** the most recent version.
10465 typedef struct sqlite3_snapshot {
10466 unsigned char hidden[48];
10467 } sqlite3_snapshot;
10470 ** CAPI3REF: Record A Database Snapshot
10471 ** CONSTRUCTOR: sqlite3_snapshot
10473 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
10474 ** new [sqlite3_snapshot] object that records the current state of
10475 ** schema S in database connection D. ^On success, the
10476 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
10477 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
10478 ** If there is not already a read-transaction open on schema S when
10479 ** this function is called, one is opened automatically.
10481 ** The following must be true for this function to succeed. If any of
10482 ** the following statements are false when sqlite3_snapshot_get() is
10483 ** called, SQLITE_ERROR is returned. The final value of *P is undefined
10487 ** <li> The database handle must not be in [autocommit mode].
10489 ** <li> Schema S of [database connection] D must be a [WAL mode] database.
10491 ** <li> There must not be a write transaction open on schema S of database
10494 ** <li> One or more transactions must have been written to the current wal
10495 ** file since it was created on disk (by any connection). This means
10496 ** that a snapshot cannot be taken on a wal mode database with no wal
10497 ** file immediately after it is first opened. At least one transaction
10498 ** must be written to it first.
10501 ** This function may also return SQLITE_NOMEM. If it is called with the
10502 ** database handle in autocommit mode but fails for some other reason,
10503 ** whether or not a read transaction is opened on schema S is undefined.
10505 ** The [sqlite3_snapshot] object returned from a successful call to
10506 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
10507 ** to avoid a memory leak.
10509 ** The [sqlite3_snapshot_get()] interface is only available when the
10510 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10512 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get(
10514 const char *zSchema,
10515 sqlite3_snapshot **ppSnapshot
10519 ** CAPI3REF: Start a read transaction on an historical snapshot
10520 ** METHOD: sqlite3_snapshot
10522 ** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read
10523 ** transaction or upgrades an existing one for schema S of
10524 ** [database connection] D such that the read transaction refers to
10525 ** historical [snapshot] P, rather than the most recent change to the
10526 ** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK
10527 ** on success or an appropriate [error code] if it fails.
10529 ** ^In order to succeed, the database connection must not be in
10530 ** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there
10531 ** is already a read transaction open on schema S, then the database handle
10532 ** must have no active statements (SELECT statements that have been passed
10533 ** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()).
10534 ** SQLITE_ERROR is returned if either of these conditions is violated, or
10535 ** if schema S does not exist, or if the snapshot object is invalid.
10537 ** ^A call to sqlite3_snapshot_open() will fail to open if the specified
10538 ** snapshot has been overwritten by a [checkpoint]. In this case
10539 ** SQLITE_ERROR_SNAPSHOT is returned.
10541 ** If there is already a read transaction open when this function is
10542 ** invoked, then the same read transaction remains open (on the same
10543 ** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT
10544 ** is returned. If another error code - for example SQLITE_PROTOCOL or an
10545 ** SQLITE_IOERR error code - is returned, then the final state of the
10546 ** read transaction is undefined. If SQLITE_OK is returned, then the
10547 ** read transaction is now open on database snapshot P.
10549 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
10550 ** database connection D does not know that the database file for
10551 ** schema S is in [WAL mode]. A database connection might not know
10552 ** that the database file is in [WAL mode] if there has been no prior
10553 ** I/O on that database connection, or if the database entered [WAL mode]
10554 ** after the most recent I/O on the database connection.)^
10555 ** (Hint: Run "[PRAGMA application_id]" against a newly opened
10556 ** database connection in order to make it ready to use snapshots.)
10558 ** The [sqlite3_snapshot_open()] interface is only available when the
10559 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10561 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open(
10563 const char *zSchema,
10564 sqlite3_snapshot *pSnapshot
10568 ** CAPI3REF: Destroy a snapshot
10569 ** DESTRUCTOR: sqlite3_snapshot
10571 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
10572 ** The application must eventually free every [sqlite3_snapshot] object
10573 ** using this routine to avoid a memory leak.
10575 ** The [sqlite3_snapshot_free()] interface is only available when the
10576 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10578 SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*);
10581 ** CAPI3REF: Compare the ages of two snapshot handles.
10582 ** METHOD: sqlite3_snapshot
10584 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
10585 ** of two valid snapshot handles.
10587 ** If the two snapshot handles are not associated with the same database
10588 ** file, the result of the comparison is undefined.
10590 ** Additionally, the result of the comparison is only valid if both of the
10591 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the
10592 ** last time the wal file was deleted. The wal file is deleted when the
10593 ** database is changed back to rollback mode or when the number of database
10594 ** clients drops to zero. If either snapshot handle was obtained before the
10595 ** wal file was last deleted, the value returned by this function
10598 ** Otherwise, this API returns a negative value if P1 refers to an older
10599 ** snapshot than P2, zero if the two handles refer to the same database
10600 ** snapshot, and a positive value if P1 is a newer snapshot than P2.
10602 ** This interface is only available if SQLite is compiled with the
10603 ** [SQLITE_ENABLE_SNAPSHOT] option.
10605 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp(
10606 sqlite3_snapshot *p1,
10607 sqlite3_snapshot *p2
10611 ** CAPI3REF: Recover snapshots from a wal file
10612 ** METHOD: sqlite3_snapshot
10614 ** If a [WAL file] remains on disk after all database connections close
10615 ** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control]
10616 ** or because the last process to have the database opened exited without
10617 ** calling [sqlite3_close()]) and a new connection is subsequently opened
10618 ** on that database and [WAL file], the [sqlite3_snapshot_open()] interface
10619 ** will only be able to open the last transaction added to the WAL file
10620 ** even though the WAL file contains other valid transactions.
10622 ** This function attempts to scan the WAL file associated with database zDb
10623 ** of database handle db and make all valid snapshots available to
10624 ** sqlite3_snapshot_open(). It is an error if there is already a read
10625 ** transaction open on the database, or if the database is not a WAL mode
10628 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
10630 ** This interface is only available if SQLite is compiled with the
10631 ** [SQLITE_ENABLE_SNAPSHOT] option.
10633 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb);
10636 ** CAPI3REF: Serialize a database
10638 ** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory
10639 ** that is a serialization of the S database on [database connection] D.
10640 ** If P is not a NULL pointer, then the size of the database in bytes
10641 ** is written into *P.
10643 ** For an ordinary on-disk database file, the serialization is just a
10644 ** copy of the disk file. For an in-memory database or a "TEMP" database,
10645 ** the serialization is the same sequence of bytes which would be written
10646 ** to disk if that database where backed up to disk.
10648 ** The usual case is that sqlite3_serialize() copies the serialization of
10649 ** the database into memory obtained from [sqlite3_malloc64()] and returns
10650 ** a pointer to that memory. The caller is responsible for freeing the
10651 ** returned value to avoid a memory leak. However, if the F argument
10652 ** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations
10653 ** are made, and the sqlite3_serialize() function will return a pointer
10654 ** to the contiguous memory representation of the database that SQLite
10655 ** is currently using for that database, or NULL if the no such contiguous
10656 ** memory representation of the database exists. A contiguous memory
10657 ** representation of the database will usually only exist if there has
10658 ** been a prior call to [sqlite3_deserialize(D,S,...)] with the same
10659 ** values of D and S.
10660 ** The size of the database is written into *P even if the
10661 ** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy
10662 ** of the database exists.
10664 ** After the call, if the SQLITE_SERIALIZE_NOCOPY bit had been set,
10665 ** the returned buffer content will remain accessible and unchanged
10666 ** until either the next write operation on the connection or when
10667 ** the connection is closed, and applications must not modify the
10668 ** buffer. If the bit had been clear, the returned buffer will not
10669 ** be accessed by SQLite after the call.
10671 ** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the
10672 ** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory
10673 ** allocation error occurs.
10675 ** This interface is omitted if SQLite is compiled with the
10676 ** [SQLITE_OMIT_DESERIALIZE] option.
10678 SQLITE_API unsigned char *sqlite3_serialize(
10679 sqlite3 *db, /* The database connection */
10680 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */
10681 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */
10682 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */
10686 ** CAPI3REF: Flags for sqlite3_serialize
10688 ** Zero or more of the following constants can be OR-ed together for
10689 ** the F argument to [sqlite3_serialize(D,S,P,F)].
10691 ** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return
10692 ** a pointer to contiguous in-memory database that it is currently using,
10693 ** without making a copy of the database. If SQLite is not currently using
10694 ** a contiguous in-memory database, then this option causes
10695 ** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be
10696 ** using a contiguous in-memory database if it has been initialized by a
10697 ** prior call to [sqlite3_deserialize()].
10699 #define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */
10702 ** CAPI3REF: Deserialize a database
10704 ** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the
10705 ** [database connection] D to disconnect from database S and then
10706 ** reopen S as an in-memory database based on the serialization contained
10707 ** in P. The serialized database P is N bytes in size. M is the size of
10708 ** the buffer P, which might be larger than N. If M is larger than N, and
10709 ** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is
10710 ** permitted to add content to the in-memory database as long as the total
10711 ** size does not exceed M bytes.
10713 ** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will
10714 ** invoke sqlite3_free() on the serialization buffer when the database
10715 ** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then
10716 ** SQLite will try to increase the buffer size using sqlite3_realloc64()
10717 ** if writes on the database cause it to grow larger than M bytes.
10719 ** Applications must not modify the buffer P or invalidate it before
10720 ** the database connection D is closed.
10722 ** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the
10723 ** database is currently in a read transaction or is involved in a backup
10726 ** It is not possible to deserialized into the TEMP database. If the
10727 ** S argument to sqlite3_deserialize(D,S,P,N,M,F) is "temp" then the
10728 ** function returns SQLITE_ERROR.
10730 ** The deserialized database should not be in [WAL mode]. If the database
10731 ** is in WAL mode, then any attempt to use the database file will result
10732 ** in an [SQLITE_CANTOPEN] error. The application can set the
10733 ** [file format version numbers] (bytes 18 and 19) of the input database P
10734 ** to 0x01 prior to invoking sqlite3_deserialize(D,S,P,N,M,F) to force the
10735 ** database file into rollback mode and work around this limitation.
10737 ** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the
10738 ** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then
10739 ** [sqlite3_free()] is invoked on argument P prior to returning.
10741 ** This interface is omitted if SQLite is compiled with the
10742 ** [SQLITE_OMIT_DESERIALIZE] option.
10744 SQLITE_API int sqlite3_deserialize(
10745 sqlite3 *db, /* The database connection */
10746 const char *zSchema, /* Which DB to reopen with the deserialization */
10747 unsigned char *pData, /* The serialized database content */
10748 sqlite3_int64 szDb, /* Number bytes in the deserialization */
10749 sqlite3_int64 szBuf, /* Total size of buffer pData[] */
10750 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */
10754 ** CAPI3REF: Flags for sqlite3_deserialize()
10756 ** The following are allowed values for 6th argument (the F argument) to
10757 ** the [sqlite3_deserialize(D,S,P,N,M,F)] interface.
10759 ** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization
10760 ** in the P argument is held in memory obtained from [sqlite3_malloc64()]
10761 ** and that SQLite should take ownership of this memory and automatically
10762 ** free it when it has finished using it. Without this flag, the caller
10763 ** is responsible for freeing any dynamically allocated memory.
10765 ** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to
10766 ** grow the size of the database using calls to [sqlite3_realloc64()]. This
10767 ** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used.
10768 ** Without this flag, the deserialized database cannot increase in size beyond
10769 ** the number of bytes specified by the M parameter.
10771 ** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database
10772 ** should be treated as read-only.
10774 #define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */
10775 #define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */
10776 #define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */
10779 ** Undo the hack that converts floating point types to integer for
10780 ** builds on processors without floating point support.
10782 #ifdef SQLITE_OMIT_FLOATING_POINT
10786 #if defined(__wasi__)
10787 # undef SQLITE_WASI
10788 # define SQLITE_WASI 1
10789 # undef SQLITE_OMIT_WAL
10790 # define SQLITE_OMIT_WAL 1/* because it requires shared memory APIs */
10791 # ifndef SQLITE_OMIT_LOAD_EXTENSION
10792 # define SQLITE_OMIT_LOAD_EXTENSION
10794 # ifndef SQLITE_THREADSAFE
10795 # define SQLITE_THREADSAFE 0
10800 } /* End of the 'extern "C"' block */
10802 #endif /* SQLITE3_H */
10804 /******** Begin file sqlite3rtree.h *********/
10808 ** The author disclaims copyright to this source code. In place of
10809 ** a legal notice, here is a blessing:
10811 ** May you do good and not evil.
10812 ** May you find forgiveness for yourself and forgive others.
10813 ** May you share freely, never taking more than you give.
10815 *************************************************************************
10818 #ifndef _SQLITE3RTREE_H_
10819 #define _SQLITE3RTREE_H_
10826 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
10827 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
10829 /* The double-precision datatype used by RTree depends on the
10830 ** SQLITE_RTREE_INT_ONLY compile-time option.
10832 #ifdef SQLITE_RTREE_INT_ONLY
10833 typedef sqlite3_int64 sqlite3_rtree_dbl;
10835 typedef double sqlite3_rtree_dbl;
10839 ** Register a geometry callback named zGeom that can be used as part of an
10840 ** R-Tree geometry query as follows:
10842 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
10844 SQLITE_API int sqlite3_rtree_geometry_callback(
10847 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
10853 ** A pointer to a structure of the following type is passed as the first
10854 ** argument to callbacks registered using rtree_geometry_callback().
10856 struct sqlite3_rtree_geometry {
10857 void *pContext; /* Copy of pContext passed to s_r_g_c() */
10858 int nParam; /* Size of array aParam[] */
10859 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */
10860 void *pUser; /* Callback implementation user data */
10861 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */
10865 ** Register a 2nd-generation geometry callback named zScore that can be
10866 ** used as part of an R-Tree geometry query as follows:
10868 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
10870 SQLITE_API int sqlite3_rtree_query_callback(
10872 const char *zQueryFunc,
10873 int (*xQueryFunc)(sqlite3_rtree_query_info*),
10875 void (*xDestructor)(void*)
10880 ** A pointer to a structure of the following type is passed as the
10881 ** argument to scored geometry callback registered using
10882 ** sqlite3_rtree_query_callback().
10884 ** Note that the first 5 fields of this structure are identical to
10885 ** sqlite3_rtree_geometry. This structure is a subclass of
10886 ** sqlite3_rtree_geometry.
10888 struct sqlite3_rtree_query_info {
10889 void *pContext; /* pContext from when function registered */
10890 int nParam; /* Number of function parameters */
10891 sqlite3_rtree_dbl *aParam; /* value of function parameters */
10892 void *pUser; /* callback can use this, if desired */
10893 void (*xDelUser)(void*); /* function to free pUser */
10894 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */
10895 unsigned int *anQueue; /* Number of pending entries in the queue */
10896 int nCoord; /* Number of coordinates */
10897 int iLevel; /* Level of current node or entry */
10898 int mxLevel; /* The largest iLevel value in the tree */
10899 sqlite3_int64 iRowid; /* Rowid for current entry */
10900 sqlite3_rtree_dbl rParentScore; /* Score of parent node */
10901 int eParentWithin; /* Visibility of parent node */
10902 int eWithin; /* OUT: Visibility */
10903 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */
10904 /* The following fields are only available in 3.8.11 and later */
10905 sqlite3_value **apSqlParam; /* Original SQL values of parameters */
10909 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
10911 #define NOT_WITHIN 0 /* Object completely outside of query region */
10912 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */
10913 #define FULLY_WITHIN 2 /* Object fully contained within query region */
10917 } /* end of the 'extern "C"' block */
10920 #endif /* ifndef _SQLITE3RTREE_H_ */
10922 /******** End of sqlite3rtree.h *********/
10923 /******** Begin file sqlite3session.h *********/
10925 #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
10926 #define __SQLITESESSION_H_ 1
10929 ** Make sure we can call this stuff from C++.
10937 ** CAPI3REF: Session Object Handle
10939 ** An instance of this object is a [session] that can be used to
10940 ** record changes to a database.
10942 typedef struct sqlite3_session sqlite3_session;
10945 ** CAPI3REF: Changeset Iterator Handle
10947 ** An instance of this object acts as a cursor for iterating
10948 ** over the elements of a [changeset] or [patchset].
10950 typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
10953 ** CAPI3REF: Create A New Session Object
10954 ** CONSTRUCTOR: sqlite3_session
10956 ** Create a new session object attached to database handle db. If successful,
10957 ** a pointer to the new object is written to *ppSession and SQLITE_OK is
10958 ** returned. If an error occurs, *ppSession is set to NULL and an SQLite
10959 ** error code (e.g. SQLITE_NOMEM) is returned.
10961 ** It is possible to create multiple session objects attached to a single
10962 ** database handle.
10964 ** Session objects created using this function should be deleted using the
10965 ** [sqlite3session_delete()] function before the database handle that they
10966 ** are attached to is itself closed. If the database handle is closed before
10967 ** the session object is deleted, then the results of calling any session
10968 ** module function, including [sqlite3session_delete()] on the session object
10971 ** Because the session module uses the [sqlite3_preupdate_hook()] API, it
10972 ** is not possible for an application to register a pre-update hook on a
10973 ** database handle that has one or more session objects attached. Nor is
10974 ** it possible to create a session object attached to a database handle for
10975 ** which a pre-update hook is already defined. The results of attempting
10976 ** either of these things are undefined.
10978 ** The session object will be used to create changesets for tables in
10979 ** database zDb, where zDb is either "main", or "temp", or the name of an
10980 ** attached database. It is not an error if database zDb is not attached
10981 ** to the database when the session object is created.
10983 SQLITE_API int sqlite3session_create(
10984 sqlite3 *db, /* Database handle */
10985 const char *zDb, /* Name of db (e.g. "main") */
10986 sqlite3_session **ppSession /* OUT: New session object */
10990 ** CAPI3REF: Delete A Session Object
10991 ** DESTRUCTOR: sqlite3_session
10993 ** Delete a session object previously allocated using
10994 ** [sqlite3session_create()]. Once a session object has been deleted, the
10995 ** results of attempting to use pSession with any other session module
10996 ** function are undefined.
10998 ** Session objects must be deleted before the database handle to which they
10999 ** are attached is closed. Refer to the documentation for
11000 ** [sqlite3session_create()] for details.
11002 SQLITE_API void sqlite3session_delete(sqlite3_session *pSession);
11005 ** CAPI3REF: Configure a Session Object
11006 ** METHOD: sqlite3_session
11008 ** This method is used to configure a session object after it has been
11009 ** created. At present the only valid values for the second parameter are
11010 ** [SQLITE_SESSION_OBJCONFIG_SIZE] and [SQLITE_SESSION_OBJCONFIG_ROWID].
11013 SQLITE_API int sqlite3session_object_config(sqlite3_session*, int op, void *pArg);
11016 ** CAPI3REF: Options for sqlite3session_object_config
11018 ** The following values may passed as the the 2nd parameter to
11019 ** sqlite3session_object_config().
11021 ** <dt>SQLITE_SESSION_OBJCONFIG_SIZE <dd>
11022 ** This option is used to set, clear or query the flag that enables
11023 ** the [sqlite3session_changeset_size()] API. Because it imposes some
11024 ** computational overhead, this API is disabled by default. Argument
11025 ** pArg must point to a value of type (int). If the value is initially
11026 ** 0, then the sqlite3session_changeset_size() API is disabled. If it
11027 ** is greater than 0, then the same API is enabled. Or, if the initial
11028 ** value is less than zero, no change is made. In all cases the (int)
11029 ** variable is set to 1 if the sqlite3session_changeset_size() API is
11030 ** enabled following the current call, or 0 otherwise.
11032 ** It is an error (SQLITE_MISUSE) to attempt to modify this setting after
11033 ** the first table has been attached to the session object.
11035 ** <dt>SQLITE_SESSION_OBJCONFIG_ROWID <dd>
11036 ** This option is used to set, clear or query the flag that enables
11037 ** collection of data for tables with no explicit PRIMARY KEY.
11039 ** Normally, tables with no explicit PRIMARY KEY are simply ignored
11040 ** by the sessions module. However, if this flag is set, it behaves
11041 ** as if such tables have a column "_rowid_ INTEGER PRIMARY KEY" inserted
11042 ** as their leftmost columns.
11044 ** It is an error (SQLITE_MISUSE) to attempt to modify this setting after
11045 ** the first table has been attached to the session object.
11047 #define SQLITE_SESSION_OBJCONFIG_SIZE 1
11048 #define SQLITE_SESSION_OBJCONFIG_ROWID 2
11051 ** CAPI3REF: Enable Or Disable A Session Object
11052 ** METHOD: sqlite3_session
11054 ** Enable or disable the recording of changes by a session object. When
11055 ** enabled, a session object records changes made to the database. When
11056 ** disabled - it does not. A newly created session object is enabled.
11057 ** Refer to the documentation for [sqlite3session_changeset()] for further
11058 ** details regarding how enabling and disabling a session object affects
11059 ** the eventual changesets.
11061 ** Passing zero to this function disables the session. Passing a value
11062 ** greater than zero enables it. Passing a value less than zero is a
11063 ** no-op, and may be used to query the current state of the session.
11065 ** The return value indicates the final state of the session object: 0 if
11066 ** the session is disabled, or 1 if it is enabled.
11068 SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
11071 ** CAPI3REF: Set Or Clear the Indirect Change Flag
11072 ** METHOD: sqlite3_session
11074 ** Each change recorded by a session object is marked as either direct or
11075 ** indirect. A change is marked as indirect if either:
11078 ** <li> The session object "indirect" flag is set when the change is
11080 ** <li> The change is made by an SQL trigger or foreign key action
11081 ** instead of directly as a result of a users SQL statement.
11084 ** If a single row is affected by more than one operation within a session,
11085 ** then the change is considered indirect if all operations meet the criteria
11086 ** for an indirect change above, or direct otherwise.
11088 ** This function is used to set, clear or query the session object indirect
11089 ** flag. If the second argument passed to this function is zero, then the
11090 ** indirect flag is cleared. If it is greater than zero, the indirect flag
11091 ** is set. Passing a value less than zero does not modify the current value
11092 ** of the indirect flag, and may be used to query the current state of the
11093 ** indirect flag for the specified session object.
11095 ** The return value indicates the final state of the indirect flag: 0 if
11096 ** it is clear, or 1 if it is set.
11098 SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
11101 ** CAPI3REF: Attach A Table To A Session Object
11102 ** METHOD: sqlite3_session
11104 ** If argument zTab is not NULL, then it is the name of a table to attach
11105 ** to the session object passed as the first argument. All subsequent changes
11106 ** made to the table while the session object is enabled will be recorded. See
11107 ** documentation for [sqlite3session_changeset()] for further details.
11109 ** Or, if argument zTab is NULL, then changes are recorded for all tables
11110 ** in the database. If additional tables are added to the database (by
11111 ** executing "CREATE TABLE" statements) after this call is made, changes for
11112 ** the new tables are also recorded.
11114 ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
11115 ** defined as part of their CREATE TABLE statement. It does not matter if the
11116 ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
11117 ** KEY may consist of a single column, or may be a composite key.
11119 ** It is not an error if the named table does not exist in the database. Nor
11120 ** is it an error if the named table does not have a PRIMARY KEY. However,
11121 ** no changes will be recorded in either of these scenarios.
11123 ** Changes are not recorded for individual rows that have NULL values stored
11124 ** in one or more of their PRIMARY KEY columns.
11126 ** SQLITE_OK is returned if the call completes without error. Or, if an error
11127 ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
11129 ** <h3>Special sqlite_stat1 Handling</h3>
11131 ** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to
11132 ** some of the rules above. In SQLite, the schema of sqlite_stat1 is:
11134 ** CREATE TABLE sqlite_stat1(tbl,idx,stat)
11137 ** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are
11138 ** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes
11139 ** are recorded for rows for which (idx IS NULL) is true. However, for such
11140 ** rows a zero-length blob (SQL value X'') is stored in the changeset or
11141 ** patchset instead of a NULL value. This allows such changesets to be
11142 ** manipulated by legacy implementations of sqlite3changeset_invert(),
11143 ** concat() and similar.
11145 ** The sqlite3changeset_apply() function automatically converts the
11146 ** zero-length blob back to a NULL value when updating the sqlite_stat1
11147 ** table. However, if the application calls sqlite3changeset_new(),
11148 ** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset
11149 ** iterator directly (including on a changeset iterator passed to a
11150 ** conflict-handler callback) then the X'' value is returned. The application
11151 ** must translate X'' to NULL itself if required.
11153 ** Legacy (older than 3.22.0) versions of the sessions module cannot capture
11154 ** changes made to the sqlite_stat1 table. Legacy versions of the
11155 ** sqlite3changeset_apply() function silently ignore any modifications to the
11156 ** sqlite_stat1 table that are part of a changeset or patchset.
11158 SQLITE_API int sqlite3session_attach(
11159 sqlite3_session *pSession, /* Session object */
11160 const char *zTab /* Table name */
11164 ** CAPI3REF: Set a table filter on a Session Object.
11165 ** METHOD: sqlite3_session
11167 ** The second argument (xFilter) is the "filter callback". For changes to rows
11168 ** in tables that are not attached to the Session object, the filter is called
11169 ** to determine whether changes to the table's rows should be tracked or not.
11170 ** If xFilter returns 0, changes are not tracked. Note that once a table is
11171 ** attached, xFilter will not be called again.
11173 SQLITE_API void sqlite3session_table_filter(
11174 sqlite3_session *pSession, /* Session object */
11176 void *pCtx, /* Copy of third arg to _filter_table() */
11177 const char *zTab /* Table name */
11179 void *pCtx /* First argument passed to xFilter */
11183 ** CAPI3REF: Generate A Changeset From A Session Object
11184 ** METHOD: sqlite3_session
11186 ** Obtain a changeset containing changes to the tables attached to the
11187 ** session object passed as the first argument. If successful,
11188 ** set *ppChangeset to point to a buffer containing the changeset
11189 ** and *pnChangeset to the size of the changeset in bytes before returning
11190 ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
11191 ** zero and return an SQLite error code.
11193 ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
11194 ** each representing a change to a single row of an attached table. An INSERT
11195 ** change contains the values of each field of a new database row. A DELETE
11196 ** contains the original values of each field of a deleted database row. An
11197 ** UPDATE change contains the original values of each field of an updated
11198 ** database row along with the updated values for each updated non-primary-key
11199 ** column. It is not possible for an UPDATE change to represent a change that
11200 ** modifies the values of primary key columns. If such a change is made, it
11201 ** is represented in a changeset as a DELETE followed by an INSERT.
11203 ** Changes are not recorded for rows that have NULL values stored in one or
11204 ** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
11205 ** no corresponding change is present in the changesets returned by this
11206 ** function. If an existing row with one or more NULL values stored in
11207 ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
11208 ** only an INSERT is appears in the changeset. Similarly, if an existing row
11209 ** with non-NULL PRIMARY KEY values is updated so that one or more of its
11210 ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
11211 ** DELETE change only.
11213 ** The contents of a changeset may be traversed using an iterator created
11214 ** using the [sqlite3changeset_start()] API. A changeset may be applied to
11215 ** a database with a compatible schema using the [sqlite3changeset_apply()]
11218 ** Within a changeset generated by this function, all changes related to a
11219 ** single table are grouped together. In other words, when iterating through
11220 ** a changeset or when applying a changeset to a database, all changes related
11221 ** to a single table are processed before moving on to the next table. Tables
11222 ** are sorted in the same order in which they were attached (or auto-attached)
11223 ** to the sqlite3_session object. The order in which the changes related to
11224 ** a single table are stored is undefined.
11226 ** Following a successful call to this function, it is the responsibility of
11227 ** the caller to eventually free the buffer that *ppChangeset points to using
11228 ** [sqlite3_free()].
11230 ** <h3>Changeset Generation</h3>
11232 ** Once a table has been attached to a session object, the session object
11233 ** records the primary key values of all new rows inserted into the table.
11234 ** It also records the original primary key and other column values of any
11235 ** deleted or updated rows. For each unique primary key value, data is only
11236 ** recorded once - the first time a row with said primary key is inserted,
11237 ** updated or deleted in the lifetime of the session.
11239 ** There is one exception to the previous paragraph: when a row is inserted,
11240 ** updated or deleted, if one or more of its primary key columns contain a
11241 ** NULL value, no record of the change is made.
11243 ** The session object therefore accumulates two types of records - those
11244 ** that consist of primary key values only (created when the user inserts
11245 ** a new record) and those that consist of the primary key values and the
11246 ** original values of other table columns (created when the users deletes
11247 ** or updates a record).
11249 ** When this function is called, the requested changeset is created using
11250 ** both the accumulated records and the current contents of the database
11251 ** file. Specifically:
11254 ** <li> For each record generated by an insert, the database is queried
11255 ** for a row with a matching primary key. If one is found, an INSERT
11256 ** change is added to the changeset. If no such row is found, no change
11257 ** is added to the changeset.
11259 ** <li> For each record generated by an update or delete, the database is
11260 ** queried for a row with a matching primary key. If such a row is
11261 ** found and one or more of the non-primary key fields have been
11262 ** modified from their original values, an UPDATE change is added to
11263 ** the changeset. Or, if no such row is found in the table, a DELETE
11264 ** change is added to the changeset. If there is a row with a matching
11265 ** primary key in the database, but all fields contain their original
11266 ** values, no change is added to the changeset.
11269 ** This means, amongst other things, that if a row is inserted and then later
11270 ** deleted while a session object is active, neither the insert nor the delete
11271 ** will be present in the changeset. Or if a row is deleted and then later a
11272 ** row with the same primary key values inserted while a session object is
11273 ** active, the resulting changeset will contain an UPDATE change instead of
11274 ** a DELETE and an INSERT.
11276 ** When a session object is disabled (see the [sqlite3session_enable()] API),
11277 ** it does not accumulate records when rows are inserted, updated or deleted.
11278 ** This may appear to have some counter-intuitive effects if a single row
11279 ** is written to more than once during a session. For example, if a row
11280 ** is inserted while a session object is enabled, then later deleted while
11281 ** the same session object is disabled, no INSERT record will appear in the
11282 ** changeset, even though the delete took place while the session was disabled.
11283 ** Or, if one field of a row is updated while a session is disabled, and
11284 ** another field of the same row is updated while the session is enabled, the
11285 ** resulting changeset will contain an UPDATE change that updates both fields.
11287 SQLITE_API int sqlite3session_changeset(
11288 sqlite3_session *pSession, /* Session object */
11289 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */
11290 void **ppChangeset /* OUT: Buffer containing changeset */
11294 ** CAPI3REF: Return An Upper-limit For The Size Of The Changeset
11295 ** METHOD: sqlite3_session
11297 ** By default, this function always returns 0. For it to return
11298 ** a useful result, the sqlite3_session object must have been configured
11299 ** to enable this API using sqlite3session_object_config() with the
11300 ** SQLITE_SESSION_OBJCONFIG_SIZE verb.
11302 ** When enabled, this function returns an upper limit, in bytes, for the size
11303 ** of the changeset that might be produced if sqlite3session_changeset() were
11304 ** called. The final changeset size might be equal to or smaller than the
11305 ** size in bytes returned by this function.
11307 SQLITE_API sqlite3_int64 sqlite3session_changeset_size(sqlite3_session *pSession);
11310 ** CAPI3REF: Load The Difference Between Tables Into A Session
11311 ** METHOD: sqlite3_session
11313 ** If it is not already attached to the session object passed as the first
11314 ** argument, this function attaches table zTbl in the same manner as the
11315 ** [sqlite3session_attach()] function. If zTbl does not exist, or if it
11316 ** does not have a primary key, this function is a no-op (but does not return
11319 ** Argument zFromDb must be the name of a database ("main", "temp" etc.)
11320 ** attached to the same database handle as the session object that contains
11321 ** a table compatible with the table attached to the session by this function.
11322 ** A table is considered compatible if it:
11325 ** <li> Has the same name,
11326 ** <li> Has the same set of columns declared in the same order, and
11327 ** <li> Has the same PRIMARY KEY definition.
11330 ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
11331 ** are compatible but do not have any PRIMARY KEY columns, it is not an error
11332 ** but no changes are added to the session object. As with other session
11333 ** APIs, tables without PRIMARY KEYs are simply ignored.
11335 ** This function adds a set of changes to the session object that could be
11336 ** used to update the table in database zFrom (call this the "from-table")
11337 ** so that its content is the same as the table attached to the session
11338 ** object (call this the "to-table"). Specifically:
11341 ** <li> For each row (primary key) that exists in the to-table but not in
11342 ** the from-table, an INSERT record is added to the session object.
11344 ** <li> For each row (primary key) that exists in the to-table but not in
11345 ** the from-table, a DELETE record is added to the session object.
11347 ** <li> For each row (primary key) that exists in both tables, but features
11348 ** different non-PK values in each, an UPDATE record is added to the
11352 ** To clarify, if this function is called and then a changeset constructed
11353 ** using [sqlite3session_changeset()], then after applying that changeset to
11354 ** database zFrom the contents of the two compatible tables would be
11357 ** It an error if database zFrom does not exist or does not contain the
11358 ** required compatible table.
11360 ** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite
11361 ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
11362 ** may be set to point to a buffer containing an English language error
11363 ** message. It is the responsibility of the caller to free this buffer using
11366 SQLITE_API int sqlite3session_diff(
11367 sqlite3_session *pSession,
11368 const char *zFromDb,
11375 ** CAPI3REF: Generate A Patchset From A Session Object
11376 ** METHOD: sqlite3_session
11378 ** The differences between a patchset and a changeset are that:
11381 ** <li> DELETE records consist of the primary key fields only. The
11382 ** original values of other fields are omitted.
11383 ** <li> The original values of any modified fields are omitted from
11387 ** A patchset blob may be used with up to date versions of all
11388 ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(),
11389 ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
11390 ** attempting to use a patchset blob with old versions of the
11391 ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error.
11393 ** Because the non-primary key "old.*" fields are omitted, no
11394 ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
11395 ** is passed to the sqlite3changeset_apply() API. Other conflict types work
11396 ** in the same way as for changesets.
11398 ** Changes within a patchset are ordered in the same way as for changesets
11399 ** generated by the sqlite3session_changeset() function (i.e. all changes for
11400 ** a single table are grouped together, tables appear in the order in which
11401 ** they were attached to the session object).
11403 SQLITE_API int sqlite3session_patchset(
11404 sqlite3_session *pSession, /* Session object */
11405 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */
11406 void **ppPatchset /* OUT: Buffer containing patchset */
11410 ** CAPI3REF: Test if a changeset has recorded any changes.
11412 ** Return non-zero if no changes to attached tables have been recorded by
11413 ** the session object passed as the first argument. Otherwise, if one or
11414 ** more changes have been recorded, return zero.
11416 ** Even if this function returns zero, it is possible that calling
11417 ** [sqlite3session_changeset()] on the session handle may still return a
11418 ** changeset that contains no changes. This can happen when a row in
11419 ** an attached table is modified and then later on the original values
11420 ** are restored. However, if this function returns non-zero, then it is
11421 ** guaranteed that a call to sqlite3session_changeset() will return a
11422 ** changeset containing zero changes.
11424 SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession);
11427 ** CAPI3REF: Query for the amount of heap memory used by a session object.
11429 ** This API returns the total amount of heap memory in bytes currently
11430 ** used by the session object passed as the only argument.
11432 SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession);
11435 ** CAPI3REF: Create An Iterator To Traverse A Changeset
11436 ** CONSTRUCTOR: sqlite3_changeset_iter
11438 ** Create an iterator used to iterate through the contents of a changeset.
11439 ** If successful, *pp is set to point to the iterator handle and SQLITE_OK
11440 ** is returned. Otherwise, if an error occurs, *pp is set to zero and an
11441 ** SQLite error code is returned.
11443 ** The following functions can be used to advance and query a changeset
11444 ** iterator created by this function:
11447 ** <li> [sqlite3changeset_next()]
11448 ** <li> [sqlite3changeset_op()]
11449 ** <li> [sqlite3changeset_new()]
11450 ** <li> [sqlite3changeset_old()]
11453 ** It is the responsibility of the caller to eventually destroy the iterator
11454 ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
11455 ** changeset (pChangeset) must remain valid until after the iterator is
11458 ** Assuming the changeset blob was created by one of the
11459 ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
11460 ** [sqlite3changeset_invert()] functions, all changes within the changeset
11461 ** that apply to a single table are grouped together. This means that when
11462 ** an application iterates through a changeset using an iterator created by
11463 ** this function, all changes that relate to a single table are visited
11464 ** consecutively. There is no chance that the iterator will visit a change
11465 ** the applies to table X, then one for table Y, and then later on visit
11466 ** another change for table X.
11468 ** The behavior of sqlite3changeset_start_v2() and its streaming equivalent
11469 ** may be modified by passing a combination of
11470 ** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter.
11472 ** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b>
11473 ** and therefore subject to change.
11475 SQLITE_API int sqlite3changeset_start(
11476 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
11477 int nChangeset, /* Size of changeset blob in bytes */
11478 void *pChangeset /* Pointer to blob containing changeset */
11480 SQLITE_API int sqlite3changeset_start_v2(
11481 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
11482 int nChangeset, /* Size of changeset blob in bytes */
11483 void *pChangeset, /* Pointer to blob containing changeset */
11484 int flags /* SESSION_CHANGESETSTART_* flags */
11488 ** CAPI3REF: Flags for sqlite3changeset_start_v2
11490 ** The following flags may passed via the 4th parameter to
11491 ** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]:
11493 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
11494 ** Invert the changeset while iterating through it. This is equivalent to
11495 ** inverting a changeset using sqlite3changeset_invert() before applying it.
11496 ** It is an error to specify this flag with a patchset.
11498 #define SQLITE_CHANGESETSTART_INVERT 0x0002
11502 ** CAPI3REF: Advance A Changeset Iterator
11503 ** METHOD: sqlite3_changeset_iter
11505 ** This function may only be used with iterators created by the function
11506 ** [sqlite3changeset_start()]. If it is called on an iterator passed to
11507 ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
11508 ** is returned and the call has no effect.
11510 ** Immediately after an iterator is created by sqlite3changeset_start(), it
11511 ** does not point to any change in the changeset. Assuming the changeset
11512 ** is not empty, the first call to this function advances the iterator to
11513 ** point to the first change in the changeset. Each subsequent call advances
11514 ** the iterator to point to the next change in the changeset (if any). If
11515 ** no error occurs and the iterator points to a valid change after a call
11516 ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned.
11517 ** Otherwise, if all changes in the changeset have already been visited,
11518 ** SQLITE_DONE is returned.
11520 ** If an error occurs, an SQLite error code is returned. Possible error
11521 ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or
11524 SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
11527 ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
11528 ** METHOD: sqlite3_changeset_iter
11530 ** The pIter argument passed to this function may either be an iterator
11531 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11532 ** created by [sqlite3changeset_start()]. In the latter case, the most recent
11533 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
11534 ** is not the case, this function returns [SQLITE_MISUSE].
11536 ** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three
11537 ** outputs are set through these pointers:
11539 ** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE],
11540 ** depending on the type of change that the iterator currently points to;
11542 ** *pnCol is set to the number of columns in the table affected by the change; and
11544 ** *pzTab is set to point to a nul-terminated utf-8 encoded string containing
11545 ** the name of the table affected by the current change. The buffer remains
11546 ** valid until either sqlite3changeset_next() is called on the iterator
11547 ** or until the conflict-handler function returns.
11549 ** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change
11550 ** is an indirect change, or false (0) otherwise. See the documentation for
11551 ** [sqlite3session_indirect()] for a description of direct and indirect
11554 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an
11555 ** SQLite error code is returned. The values of the output variables may not
11556 ** be trusted in this case.
11558 SQLITE_API int sqlite3changeset_op(
11559 sqlite3_changeset_iter *pIter, /* Iterator object */
11560 const char **pzTab, /* OUT: Pointer to table name */
11561 int *pnCol, /* OUT: Number of columns in table */
11562 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */
11563 int *pbIndirect /* OUT: True for an 'indirect' change */
11567 ** CAPI3REF: Obtain The Primary Key Definition Of A Table
11568 ** METHOD: sqlite3_changeset_iter
11570 ** For each modified table, a changeset includes the following:
11573 ** <li> The number of columns in the table, and
11574 ** <li> Which of those columns make up the tables PRIMARY KEY.
11577 ** This function is used to find which columns comprise the PRIMARY KEY of
11578 ** the table modified by the change that iterator pIter currently points to.
11579 ** If successful, *pabPK is set to point to an array of nCol entries, where
11580 ** nCol is the number of columns in the table. Elements of *pabPK are set to
11581 ** 0x01 if the corresponding column is part of the tables primary key, or
11582 ** 0x00 if it is not.
11584 ** If argument pnCol is not NULL, then *pnCol is set to the number of columns
11587 ** If this function is called when the iterator does not point to a valid
11588 ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
11589 ** SQLITE_OK is returned and the output variables populated as described
11592 SQLITE_API int sqlite3changeset_pk(
11593 sqlite3_changeset_iter *pIter, /* Iterator object */
11594 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */
11595 int *pnCol /* OUT: Number of entries in output array */
11599 ** CAPI3REF: Obtain old.* Values From A Changeset Iterator
11600 ** METHOD: sqlite3_changeset_iter
11602 ** The pIter argument passed to this function may either be an iterator
11603 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11604 ** created by [sqlite3changeset_start()]. In the latter case, the most recent
11605 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
11606 ** Furthermore, it may only be called if the type of change that the iterator
11607 ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
11608 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
11610 ** Argument iVal must be greater than or equal to 0, and less than the number
11611 ** of columns in the table affected by the current change. Otherwise,
11612 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
11614 ** If successful, this function sets *ppValue to point to a protected
11615 ** sqlite3_value object containing the iVal'th value from the vector of
11616 ** original row values stored as part of the UPDATE or DELETE change and
11617 ** returns SQLITE_OK. The name of the function comes from the fact that this
11618 ** is similar to the "old.*" columns available to update or delete triggers.
11620 ** If some other error occurs (e.g. an OOM condition), an SQLite error code
11621 ** is returned and *ppValue is set to NULL.
11623 SQLITE_API int sqlite3changeset_old(
11624 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11625 int iVal, /* Column number */
11626 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */
11630 ** CAPI3REF: Obtain new.* Values From A Changeset Iterator
11631 ** METHOD: sqlite3_changeset_iter
11633 ** The pIter argument passed to this function may either be an iterator
11634 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11635 ** created by [sqlite3changeset_start()]. In the latter case, the most recent
11636 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
11637 ** Furthermore, it may only be called if the type of change that the iterator
11638 ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
11639 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
11641 ** Argument iVal must be greater than or equal to 0, and less than the number
11642 ** of columns in the table affected by the current change. Otherwise,
11643 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
11645 ** If successful, this function sets *ppValue to point to a protected
11646 ** sqlite3_value object containing the iVal'th value from the vector of
11647 ** new row values stored as part of the UPDATE or INSERT change and
11648 ** returns SQLITE_OK. If the change is an UPDATE and does not include
11649 ** a new value for the requested column, *ppValue is set to NULL and
11650 ** SQLITE_OK returned. The name of the function comes from the fact that
11651 ** this is similar to the "new.*" columns available to update or delete
11654 ** If some other error occurs (e.g. an OOM condition), an SQLite error code
11655 ** is returned and *ppValue is set to NULL.
11657 SQLITE_API int sqlite3changeset_new(
11658 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11659 int iVal, /* Column number */
11660 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */
11664 ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
11665 ** METHOD: sqlite3_changeset_iter
11667 ** This function should only be used with iterator objects passed to a
11668 ** conflict-handler callback by [sqlite3changeset_apply()] with either
11669 ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
11670 ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
11673 ** Argument iVal must be greater than or equal to 0, and less than the number
11674 ** of columns in the table affected by the current change. Otherwise,
11675 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
11677 ** If successful, this function sets *ppValue to point to a protected
11678 ** sqlite3_value object containing the iVal'th value from the
11679 ** "conflicting row" associated with the current conflict-handler callback
11680 ** and returns SQLITE_OK.
11682 ** If some other error occurs (e.g. an OOM condition), an SQLite error code
11683 ** is returned and *ppValue is set to NULL.
11685 SQLITE_API int sqlite3changeset_conflict(
11686 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11687 int iVal, /* Column number */
11688 sqlite3_value **ppValue /* OUT: Value from conflicting row */
11692 ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
11693 ** METHOD: sqlite3_changeset_iter
11695 ** This function may only be called with an iterator passed to an
11696 ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
11697 ** it sets the output variable to the total number of known foreign key
11698 ** violations in the destination database and returns SQLITE_OK.
11700 ** In all other cases this function returns SQLITE_MISUSE.
11702 SQLITE_API int sqlite3changeset_fk_conflicts(
11703 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11704 int *pnOut /* OUT: Number of FK violations */
11709 ** CAPI3REF: Finalize A Changeset Iterator
11710 ** METHOD: sqlite3_changeset_iter
11712 ** This function is used to finalize an iterator allocated with
11713 ** [sqlite3changeset_start()].
11715 ** This function should only be called on iterators created using the
11716 ** [sqlite3changeset_start()] function. If an application calls this
11717 ** function with an iterator passed to a conflict-handler by
11718 ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
11719 ** call has no effect.
11721 ** If an error was encountered within a call to an sqlite3changeset_xxx()
11722 ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an
11723 ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
11724 ** to that error is returned by this function. Otherwise, SQLITE_OK is
11725 ** returned. This is to allow the following pattern (pseudo-code):
11728 ** sqlite3changeset_start();
11729 ** while( SQLITE_ROW==sqlite3changeset_next() ){
11730 ** // Do something with change.
11732 ** rc = sqlite3changeset_finalize();
11733 ** if( rc!=SQLITE_OK ){
11734 ** // An error has occurred
11738 SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
11741 ** CAPI3REF: Invert A Changeset
11743 ** This function is used to "invert" a changeset object. Applying an inverted
11744 ** changeset to a database reverses the effects of applying the uninverted
11745 ** changeset. Specifically:
11748 ** <li> Each DELETE change is changed to an INSERT, and
11749 ** <li> Each INSERT change is changed to a DELETE, and
11750 ** <li> For each UPDATE change, the old.* and new.* values are exchanged.
11753 ** This function does not change the order in which changes appear within
11754 ** the changeset. It merely reverses the sense of each individual change.
11756 ** If successful, a pointer to a buffer containing the inverted changeset
11757 ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
11758 ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
11759 ** zeroed and an SQLite error code returned.
11761 ** It is the responsibility of the caller to eventually call sqlite3_free()
11762 ** on the *ppOut pointer to free the buffer allocation following a successful
11763 ** call to this function.
11765 ** WARNING/TODO: This function currently assumes that the input is a valid
11766 ** changeset. If it is not, the results are undefined.
11768 SQLITE_API int sqlite3changeset_invert(
11769 int nIn, const void *pIn, /* Input changeset */
11770 int *pnOut, void **ppOut /* OUT: Inverse of input */
11774 ** CAPI3REF: Concatenate Two Changeset Objects
11776 ** This function is used to concatenate two changesets, A and B, into a
11777 ** single changeset. The result is a changeset equivalent to applying
11778 ** changeset A followed by changeset B.
11780 ** This function combines the two input changesets using an
11781 ** sqlite3_changegroup object. Calling it produces similar results as the
11782 ** following code fragment:
11785 ** sqlite3_changegroup *pGrp;
11786 ** rc = sqlite3_changegroup_new(&pGrp);
11787 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
11788 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
11789 ** if( rc==SQLITE_OK ){
11790 ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
11797 ** Refer to the sqlite3_changegroup documentation below for details.
11799 SQLITE_API int sqlite3changeset_concat(
11800 int nA, /* Number of bytes in buffer pA */
11801 void *pA, /* Pointer to buffer containing changeset A */
11802 int nB, /* Number of bytes in buffer pB */
11803 void *pB, /* Pointer to buffer containing changeset B */
11804 int *pnOut, /* OUT: Number of bytes in output changeset */
11805 void **ppOut /* OUT: Buffer containing output changeset */
11810 ** CAPI3REF: Upgrade the Schema of a Changeset/Patchset
11812 SQLITE_API int sqlite3changeset_upgrade(
11815 int nIn, const void *pIn, /* Input changeset */
11816 int *pnOut, void **ppOut /* OUT: Inverse of input */
11822 ** CAPI3REF: Changegroup Handle
11824 ** A changegroup is an object used to combine two or more
11825 ** [changesets] or [patchsets]
11827 typedef struct sqlite3_changegroup sqlite3_changegroup;
11830 ** CAPI3REF: Create A New Changegroup Object
11831 ** CONSTRUCTOR: sqlite3_changegroup
11833 ** An sqlite3_changegroup object is used to combine two or more changesets
11834 ** (or patchsets) into a single changeset (or patchset). A single changegroup
11835 ** object may combine changesets or patchsets, but not both. The output is
11836 ** always in the same format as the input.
11838 ** If successful, this function returns SQLITE_OK and populates (*pp) with
11839 ** a pointer to a new sqlite3_changegroup object before returning. The caller
11840 ** should eventually free the returned object using a call to
11841 ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
11842 ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
11844 ** The usual usage pattern for an sqlite3_changegroup object is as follows:
11847 ** <li> It is created using a call to sqlite3changegroup_new().
11849 ** <li> Zero or more changesets (or patchsets) are added to the object
11850 ** by calling sqlite3changegroup_add().
11852 ** <li> The result of combining all input changesets together is obtained
11853 ** by the application via a call to sqlite3changegroup_output().
11855 ** <li> The object is deleted using a call to sqlite3changegroup_delete().
11858 ** Any number of calls to add() and output() may be made between the calls to
11859 ** new() and delete(), and in any order.
11861 ** As well as the regular sqlite3changegroup_add() and
11862 ** sqlite3changegroup_output() functions, also available are the streaming
11863 ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
11865 SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp);
11868 ** CAPI3REF: Add a Schema to a Changegroup
11869 ** METHOD: sqlite3_changegroup_schema
11871 ** This method may be used to optionally enforce the rule that the changesets
11872 ** added to the changegroup handle must match the schema of database zDb
11873 ** ("main", "temp", or the name of an attached database). If
11874 ** sqlite3changegroup_add() is called to add a changeset that is not compatible
11875 ** with the configured schema, SQLITE_SCHEMA is returned and the changegroup
11876 ** object is left in an undefined state.
11878 ** A changeset schema is considered compatible with the database schema in
11879 ** the same way as for sqlite3changeset_apply(). Specifically, for each
11880 ** table in the changeset, there exists a database table with:
11883 ** <li> The name identified by the changeset, and
11884 ** <li> at least as many columns as recorded in the changeset, and
11885 ** <li> the primary key columns in the same position as recorded in
11889 ** The output of the changegroup object always has the same schema as the
11890 ** database nominated using this function. In cases where changesets passed
11891 ** to sqlite3changegroup_add() have fewer columns than the corresponding table
11892 ** in the database schema, these are filled in using the default column
11893 ** values from the database schema. This makes it possible to combined
11894 ** changesets that have different numbers of columns for a single table
11895 ** within a changegroup, provided that they are otherwise compatible.
11897 SQLITE_API int sqlite3changegroup_schema(sqlite3_changegroup*, sqlite3*, const char *zDb);
11900 ** CAPI3REF: Add A Changeset To A Changegroup
11901 ** METHOD: sqlite3_changegroup
11903 ** Add all changes within the changeset (or patchset) in buffer pData (size
11904 ** nData bytes) to the changegroup.
11906 ** If the buffer contains a patchset, then all prior calls to this function
11907 ** on the same changegroup object must also have specified patchsets. Or, if
11908 ** the buffer contains a changeset, so must have the earlier calls to this
11909 ** function. Otherwise, SQLITE_ERROR is returned and no changes are added
11910 ** to the changegroup.
11912 ** Rows within the changeset and changegroup are identified by the values in
11913 ** their PRIMARY KEY columns. A change in the changeset is considered to
11914 ** apply to the same row as a change already present in the changegroup if
11915 ** the two rows have the same primary key.
11917 ** Changes to rows that do not already appear in the changegroup are
11918 ** simply copied into it. Or, if both the new changeset and the changegroup
11919 ** contain changes that apply to a single row, the final contents of the
11920 ** changegroup depends on the type of each change, as follows:
11922 ** <table border=1 style="margin-left:8ex;margin-right:8ex">
11923 ** <tr><th style="white-space:pre">Existing Change </th>
11924 ** <th style="white-space:pre">New Change </th>
11925 ** <th>Output Change
11926 ** <tr><td>INSERT <td>INSERT <td>
11927 ** The new change is ignored. This case does not occur if the new
11928 ** changeset was recorded immediately after the changesets already
11929 ** added to the changegroup.
11930 ** <tr><td>INSERT <td>UPDATE <td>
11931 ** The INSERT change remains in the changegroup. The values in the
11932 ** INSERT change are modified as if the row was inserted by the
11933 ** existing change and then updated according to the new change.
11934 ** <tr><td>INSERT <td>DELETE <td>
11935 ** The existing INSERT is removed from the changegroup. The DELETE is
11937 ** <tr><td>UPDATE <td>INSERT <td>
11938 ** The new change is ignored. This case does not occur if the new
11939 ** changeset was recorded immediately after the changesets already
11940 ** added to the changegroup.
11941 ** <tr><td>UPDATE <td>UPDATE <td>
11942 ** The existing UPDATE remains within the changegroup. It is amended
11943 ** so that the accompanying values are as if the row was updated once
11944 ** by the existing change and then again by the new change.
11945 ** <tr><td>UPDATE <td>DELETE <td>
11946 ** The existing UPDATE is replaced by the new DELETE within the
11948 ** <tr><td>DELETE <td>INSERT <td>
11949 ** If one or more of the column values in the row inserted by the
11950 ** new change differ from those in the row deleted by the existing
11951 ** change, the existing DELETE is replaced by an UPDATE within the
11952 ** changegroup. Otherwise, if the inserted row is exactly the same
11953 ** as the deleted row, the existing DELETE is simply discarded.
11954 ** <tr><td>DELETE <td>UPDATE <td>
11955 ** The new change is ignored. This case does not occur if the new
11956 ** changeset was recorded immediately after the changesets already
11957 ** added to the changegroup.
11958 ** <tr><td>DELETE <td>DELETE <td>
11959 ** The new change is ignored. This case does not occur if the new
11960 ** changeset was recorded immediately after the changesets already
11961 ** added to the changegroup.
11964 ** If the new changeset contains changes to a table that is already present
11965 ** in the changegroup, then the number of columns and the position of the
11966 ** primary key columns for the table must be consistent. If this is not the
11967 ** case, this function fails with SQLITE_SCHEMA. Except, if the changegroup
11968 ** object has been configured with a database schema using the
11969 ** sqlite3changegroup_schema() API, then it is possible to combine changesets
11970 ** with different numbers of columns for a single table, provided that
11971 ** they are otherwise compatible.
11973 ** If the input changeset appears to be corrupt and the corruption is
11974 ** detected, SQLITE_CORRUPT is returned. Or, if an out-of-memory condition
11975 ** occurs during processing, this function returns SQLITE_NOMEM.
11977 ** In all cases, if an error occurs the state of the final contents of the
11978 ** changegroup is undefined. If no error occurs, SQLITE_OK is returned.
11980 SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
11983 ** CAPI3REF: Obtain A Composite Changeset From A Changegroup
11984 ** METHOD: sqlite3_changegroup
11986 ** Obtain a buffer containing a changeset (or patchset) representing the
11987 ** current contents of the changegroup. If the inputs to the changegroup
11988 ** were themselves changesets, the output is a changeset. Or, if the
11989 ** inputs were patchsets, the output is also a patchset.
11991 ** As with the output of the sqlite3session_changeset() and
11992 ** sqlite3session_patchset() functions, all changes related to a single
11993 ** table are grouped together in the output of this function. Tables appear
11994 ** in the same order as for the very first changeset added to the changegroup.
11995 ** If the second or subsequent changesets added to the changegroup contain
11996 ** changes for tables that do not appear in the first changeset, they are
11997 ** appended onto the end of the output changeset, again in the order in
11998 ** which they are first encountered.
12000 ** If an error occurs, an SQLite error code is returned and the output
12001 ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
12002 ** is returned and the output variables are set to the size of and a
12003 ** pointer to the output buffer, respectively. In this case it is the
12004 ** responsibility of the caller to eventually free the buffer using a
12005 ** call to sqlite3_free().
12007 SQLITE_API int sqlite3changegroup_output(
12008 sqlite3_changegroup*,
12009 int *pnData, /* OUT: Size of output buffer in bytes */
12010 void **ppData /* OUT: Pointer to output buffer */
12014 ** CAPI3REF: Delete A Changegroup Object
12015 ** DESTRUCTOR: sqlite3_changegroup
12017 SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*);
12020 ** CAPI3REF: Apply A Changeset To A Database
12022 ** Apply a changeset or patchset to a database. These functions attempt to
12023 ** update the "main" database attached to handle db with the changes found in
12024 ** the changeset passed via the second and third arguments.
12026 ** The fourth argument (xFilter) passed to these functions is the "filter
12027 ** callback". If it is not NULL, then for each table affected by at least one
12028 ** change in the changeset, the filter callback is invoked with
12029 ** the table name as the second argument, and a copy of the context pointer
12030 ** passed as the sixth argument as the first. If the "filter callback"
12031 ** returns zero, then no attempt is made to apply any changes to the table.
12032 ** Otherwise, if the return value is non-zero or the xFilter argument to
12033 ** is NULL, all changes related to the table are attempted.
12035 ** For each table that is not excluded by the filter callback, this function
12036 ** tests that the target database contains a compatible table. A table is
12037 ** considered compatible if all of the following are true:
12040 ** <li> The table has the same name as the name recorded in the
12042 ** <li> The table has at least as many columns as recorded in the
12044 ** <li> The table has primary key columns in the same position as
12045 ** recorded in the changeset.
12048 ** If there is no compatible table, it is not an error, but none of the
12049 ** changes associated with the table are applied. A warning message is issued
12050 ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
12051 ** one such warning is issued for each table in the changeset.
12053 ** For each change for which there is a compatible table, an attempt is made
12054 ** to modify the table contents according to the UPDATE, INSERT or DELETE
12055 ** change. If a change cannot be applied cleanly, the conflict handler
12056 ** function passed as the fifth argument to sqlite3changeset_apply() may be
12057 ** invoked. A description of exactly when the conflict handler is invoked for
12058 ** each type of change is below.
12060 ** Unlike the xFilter argument, xConflict may not be passed NULL. The results
12061 ** of passing anything other than a valid function pointer as the xConflict
12062 ** argument are undefined.
12064 ** Each time the conflict handler function is invoked, it must return one
12065 ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or
12066 ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
12067 ** if the second argument passed to the conflict handler is either
12068 ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
12069 ** returns an illegal value, any changes already made are rolled back and
12070 ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different
12071 ** actions are taken by sqlite3changeset_apply() depending on the value
12072 ** returned by each invocation of the conflict-handler function. Refer to
12073 ** the documentation for the three
12074 ** [SQLITE_CHANGESET_OMIT|available return values] for details.
12077 ** <dt>DELETE Changes<dd>
12078 ** For each DELETE change, the function checks if the target database
12079 ** contains a row with the same primary key value (or values) as the
12080 ** original row values stored in the changeset. If it does, and the values
12081 ** stored in all non-primary key columns also match the values stored in
12082 ** the changeset the row is deleted from the target database.
12084 ** If a row with matching primary key values is found, but one or more of
12085 ** the non-primary key fields contains a value different from the original
12086 ** row value stored in the changeset, the conflict-handler function is
12087 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the
12088 ** database table has more columns than are recorded in the changeset,
12089 ** only the values of those non-primary key fields are compared against
12090 ** the current database contents - any trailing database table columns
12093 ** If no row with matching primary key values is found in the database,
12094 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
12095 ** passed as the second argument.
12097 ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
12098 ** (which can only happen if a foreign key constraint is violated), the
12099 ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
12100 ** passed as the second argument. This includes the case where the DELETE
12101 ** operation is attempted because an earlier call to the conflict handler
12102 ** function returned [SQLITE_CHANGESET_REPLACE].
12104 ** <dt>INSERT Changes<dd>
12105 ** For each INSERT change, an attempt is made to insert the new row into
12106 ** the database. If the changeset row contains fewer fields than the
12107 ** database table, the trailing fields are populated with their default
12110 ** If the attempt to insert the row fails because the database already
12111 ** contains a row with the same primary key values, the conflict handler
12112 ** function is invoked with the second argument set to
12113 ** [SQLITE_CHANGESET_CONFLICT].
12115 ** If the attempt to insert the row fails because of some other constraint
12116 ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is
12117 ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
12118 ** This includes the case where the INSERT operation is re-attempted because
12119 ** an earlier call to the conflict handler function returned
12120 ** [SQLITE_CHANGESET_REPLACE].
12122 ** <dt>UPDATE Changes<dd>
12123 ** For each UPDATE change, the function checks if the target database
12124 ** contains a row with the same primary key value (or values) as the
12125 ** original row values stored in the changeset. If it does, and the values
12126 ** stored in all modified non-primary key columns also match the values
12127 ** stored in the changeset the row is updated within the target database.
12129 ** If a row with matching primary key values is found, but one or more of
12130 ** the modified non-primary key fields contains a value different from an
12131 ** original row value stored in the changeset, the conflict-handler function
12132 ** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
12133 ** UPDATE changes only contain values for non-primary key fields that are
12134 ** to be modified, only those fields need to match the original values to
12135 ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
12137 ** If no row with matching primary key values is found in the database,
12138 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
12139 ** passed as the second argument.
12141 ** If the UPDATE operation is attempted, but SQLite returns
12142 ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with
12143 ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
12144 ** This includes the case where the UPDATE operation is attempted after
12145 ** an earlier call to the conflict handler function returned
12146 ** [SQLITE_CHANGESET_REPLACE].
12149 ** It is safe to execute SQL statements, including those that write to the
12150 ** table that the callback related to, from within the xConflict callback.
12151 ** This can be used to further customize the application's conflict
12152 ** resolution strategy.
12154 ** All changes made by these functions are enclosed in a savepoint transaction.
12155 ** If any other error (aside from a constraint failure when attempting to
12156 ** write to the target database) occurs, then the savepoint transaction is
12157 ** rolled back, restoring the target database to its original state, and an
12158 ** SQLite error code returned.
12160 ** If the output parameters (ppRebase) and (pnRebase) are non-NULL and
12161 ** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2()
12162 ** may set (*ppRebase) to point to a "rebase" that may be used with the
12163 ** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase)
12164 ** is set to the size of the buffer in bytes. It is the responsibility of the
12165 ** caller to eventually free any such buffer using sqlite3_free(). The buffer
12166 ** is only allocated and populated if one or more conflicts were encountered
12167 ** while applying the patchset. See comments surrounding the sqlite3_rebaser
12168 ** APIs for further details.
12170 ** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent
12171 ** may be modified by passing a combination of
12172 ** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter.
12174 ** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b>
12175 ** and therefore subject to change.
12177 SQLITE_API int sqlite3changeset_apply(
12178 sqlite3 *db, /* Apply change to "main" db of this handle */
12179 int nChangeset, /* Size of changeset in bytes */
12180 void *pChangeset, /* Changeset blob */
12182 void *pCtx, /* Copy of sixth arg to _apply() */
12183 const char *zTab /* Table name */
12186 void *pCtx, /* Copy of sixth arg to _apply() */
12187 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12188 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12190 void *pCtx /* First argument passed to xConflict */
12192 SQLITE_API int sqlite3changeset_apply_v2(
12193 sqlite3 *db, /* Apply change to "main" db of this handle */
12194 int nChangeset, /* Size of changeset in bytes */
12195 void *pChangeset, /* Changeset blob */
12197 void *pCtx, /* Copy of sixth arg to _apply() */
12198 const char *zTab /* Table name */
12201 void *pCtx, /* Copy of sixth arg to _apply() */
12202 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12203 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12205 void *pCtx, /* First argument passed to xConflict */
12206 void **ppRebase, int *pnRebase, /* OUT: Rebase data */
12207 int flags /* SESSION_CHANGESETAPPLY_* flags */
12211 ** CAPI3REF: Flags for sqlite3changeset_apply_v2
12213 ** The following flags may passed via the 9th parameter to
12214 ** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]:
12217 ** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd>
12218 ** Usually, the sessions module encloses all operations performed by
12219 ** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The
12220 ** SAVEPOINT is committed if the changeset or patchset is successfully
12221 ** applied, or rolled back if an error occurs. Specifying this flag
12222 ** causes the sessions module to omit this savepoint. In this case, if the
12223 ** caller has an open transaction or savepoint when apply_v2() is called,
12224 ** it may revert the partially applied changeset by rolling it back.
12226 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
12227 ** Invert the changeset before applying it. This is equivalent to inverting
12228 ** a changeset using sqlite3changeset_invert() before applying it. It is
12229 ** an error to specify this flag with a patchset.
12231 ** <dt>SQLITE_CHANGESETAPPLY_IGNORENOOP <dd>
12232 ** Do not invoke the conflict handler callback for any changes that
12233 ** would not actually modify the database even if they were applied.
12234 ** Specifically, this means that the conflict handler is not invoked
12237 ** <li>a delete change if the row being deleted cannot be found,
12238 ** <li>an update change if the modified fields are already set to
12239 ** their new values in the conflicting row, or
12240 ** <li>an insert change if all fields of the conflicting row match
12241 ** the row being inserted.
12244 ** <dt>SQLITE_CHANGESETAPPLY_FKNOACTION <dd>
12245 ** If this flag it set, then all foreign key constraints in the target
12246 ** database behave as if they were declared with "ON UPDATE NO ACTION ON
12247 ** DELETE NO ACTION", even if they are actually CASCADE, RESTRICT, SET NULL
12250 #define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001
12251 #define SQLITE_CHANGESETAPPLY_INVERT 0x0002
12252 #define SQLITE_CHANGESETAPPLY_IGNORENOOP 0x0004
12253 #define SQLITE_CHANGESETAPPLY_FKNOACTION 0x0008
12256 ** CAPI3REF: Constants Passed To The Conflict Handler
12258 ** Values that may be passed as the second argument to a conflict-handler.
12261 ** <dt>SQLITE_CHANGESET_DATA<dd>
12262 ** The conflict handler is invoked with CHANGESET_DATA as the second argument
12263 ** when processing a DELETE or UPDATE change if a row with the required
12264 ** PRIMARY KEY fields is present in the database, but one or more other
12265 ** (non primary-key) fields modified by the update do not contain the
12266 ** expected "before" values.
12268 ** The conflicting row, in this case, is the database row with the matching
12271 ** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
12272 ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second
12273 ** argument when processing a DELETE or UPDATE change if a row with the
12274 ** required PRIMARY KEY fields is not present in the database.
12276 ** There is no conflicting row in this case. The results of invoking the
12277 ** sqlite3changeset_conflict() API are undefined.
12279 ** <dt>SQLITE_CHANGESET_CONFLICT<dd>
12280 ** CHANGESET_CONFLICT is passed as the second argument to the conflict
12281 ** handler while processing an INSERT change if the operation would result
12282 ** in duplicate primary key values.
12284 ** The conflicting row in this case is the database row with the matching
12287 ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
12288 ** If foreign key handling is enabled, and applying a changeset leaves the
12289 ** database in a state containing foreign key violations, the conflict
12290 ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
12291 ** exactly once before the changeset is committed. If the conflict handler
12292 ** returns CHANGESET_OMIT, the changes, including those that caused the
12293 ** foreign key constraint violation, are committed. Or, if it returns
12294 ** CHANGESET_ABORT, the changeset is rolled back.
12296 ** No current or conflicting row information is provided. The only function
12297 ** it is possible to call on the supplied sqlite3_changeset_iter handle
12298 ** is sqlite3changeset_fk_conflicts().
12300 ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
12301 ** If any other constraint violation occurs while applying a change (i.e.
12302 ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is
12303 ** invoked with CHANGESET_CONSTRAINT as the second argument.
12305 ** There is no conflicting row in this case. The results of invoking the
12306 ** sqlite3changeset_conflict() API are undefined.
12310 #define SQLITE_CHANGESET_DATA 1
12311 #define SQLITE_CHANGESET_NOTFOUND 2
12312 #define SQLITE_CHANGESET_CONFLICT 3
12313 #define SQLITE_CHANGESET_CONSTRAINT 4
12314 #define SQLITE_CHANGESET_FOREIGN_KEY 5
12317 ** CAPI3REF: Constants Returned By The Conflict Handler
12319 ** A conflict handler callback must return one of the following three values.
12322 ** <dt>SQLITE_CHANGESET_OMIT<dd>
12323 ** If a conflict handler returns this value no special action is taken. The
12324 ** change that caused the conflict is not applied. The session module
12325 ** continues to the next change in the changeset.
12327 ** <dt>SQLITE_CHANGESET_REPLACE<dd>
12328 ** This value may only be returned if the second argument to the conflict
12329 ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
12330 ** is not the case, any changes applied so far are rolled back and the
12331 ** call to sqlite3changeset_apply() returns SQLITE_MISUSE.
12333 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
12334 ** handler, then the conflicting row is either updated or deleted, depending
12335 ** on the type of change.
12337 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
12338 ** handler, then the conflicting row is removed from the database and a
12339 ** second attempt to apply the change is made. If this second attempt fails,
12340 ** the original row is restored to the database before continuing.
12342 ** <dt>SQLITE_CHANGESET_ABORT<dd>
12343 ** If this value is returned, any changes applied so far are rolled back
12344 ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
12347 #define SQLITE_CHANGESET_OMIT 0
12348 #define SQLITE_CHANGESET_REPLACE 1
12349 #define SQLITE_CHANGESET_ABORT 2
12352 ** CAPI3REF: Rebasing changesets
12355 ** Suppose there is a site hosting a database in state S0. And that
12356 ** modifications are made that move that database to state S1 and a
12357 ** changeset recorded (the "local" changeset). Then, a changeset based
12358 ** on S0 is received from another site (the "remote" changeset) and
12359 ** applied to the database. The database is then in state
12360 ** (S1+"remote"), where the exact state depends on any conflict
12361 ** resolution decisions (OMIT or REPLACE) made while applying "remote".
12362 ** Rebasing a changeset is to update it to take those conflict
12363 ** resolution decisions into account, so that the same conflicts
12364 ** do not have to be resolved elsewhere in the network.
12366 ** For example, if both the local and remote changesets contain an
12367 ** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)":
12369 ** local: INSERT INTO t1 VALUES(1, 'v1');
12370 ** remote: INSERT INTO t1 VALUES(1, 'v2');
12372 ** and the conflict resolution is REPLACE, then the INSERT change is
12373 ** removed from the local changeset (it was overridden). Or, if the
12374 ** conflict resolution was "OMIT", then the local changeset is modified
12375 ** to instead contain:
12377 ** UPDATE t1 SET b = 'v2' WHERE a=1;
12379 ** Changes within the local changeset are rebased as follows:
12382 ** <dt>Local INSERT<dd>
12383 ** This may only conflict with a remote INSERT. If the conflict
12384 ** resolution was OMIT, then add an UPDATE change to the rebased
12385 ** changeset. Or, if the conflict resolution was REPLACE, add
12386 ** nothing to the rebased changeset.
12388 ** <dt>Local DELETE<dd>
12389 ** This may conflict with a remote UPDATE or DELETE. In both cases the
12390 ** only possible resolution is OMIT. If the remote operation was a
12391 ** DELETE, then add no change to the rebased changeset. If the remote
12392 ** operation was an UPDATE, then the old.* fields of change are updated
12393 ** to reflect the new.* values in the UPDATE.
12395 ** <dt>Local UPDATE<dd>
12396 ** This may conflict with a remote UPDATE or DELETE. If it conflicts
12397 ** with a DELETE, and the conflict resolution was OMIT, then the update
12398 ** is changed into an INSERT. Any undefined values in the new.* record
12399 ** from the update change are filled in using the old.* values from
12400 ** the conflicting DELETE. Or, if the conflict resolution was REPLACE,
12401 ** the UPDATE change is simply omitted from the rebased changeset.
12403 ** If conflict is with a remote UPDATE and the resolution is OMIT, then
12404 ** the old.* values are rebased using the new.* values in the remote
12405 ** change. Or, if the resolution is REPLACE, then the change is copied
12406 ** into the rebased changeset with updates to columns also updated by
12407 ** the conflicting remote UPDATE removed. If this means no columns would
12408 ** be updated, the change is omitted.
12411 ** A local change may be rebased against multiple remote changes
12412 ** simultaneously. If a single key is modified by multiple remote
12413 ** changesets, they are combined as follows before the local changeset
12417 ** <li> If there has been one or more REPLACE resolutions on a
12418 ** key, it is rebased according to a REPLACE.
12420 ** <li> If there have been no REPLACE resolutions on a key, then
12421 ** the local changeset is rebased according to the most recent
12422 ** of the OMIT resolutions.
12425 ** Note that conflict resolutions from multiple remote changesets are
12426 ** combined on a per-field basis, not per-row. This means that in the
12427 ** case of multiple remote UPDATE operations, some fields of a single
12428 ** local change may be rebased for REPLACE while others are rebased for
12431 ** In order to rebase a local changeset, the remote changeset must first
12432 ** be applied to the local database using sqlite3changeset_apply_v2() and
12433 ** the buffer of rebase information captured. Then:
12436 ** <li> An sqlite3_rebaser object is created by calling
12437 ** sqlite3rebaser_create().
12438 ** <li> The new object is configured with the rebase buffer obtained from
12439 ** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure().
12440 ** If the local changeset is to be rebased against multiple remote
12441 ** changesets, then sqlite3rebaser_configure() should be called
12442 ** multiple times, in the same order that the multiple
12443 ** sqlite3changeset_apply_v2() calls were made.
12444 ** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase().
12445 ** <li> The sqlite3_rebaser object is deleted by calling
12446 ** sqlite3rebaser_delete().
12449 typedef struct sqlite3_rebaser sqlite3_rebaser;
12452 ** CAPI3REF: Create a changeset rebaser object.
12455 ** Allocate a new changeset rebaser object. If successful, set (*ppNew) to
12456 ** point to the new object and return SQLITE_OK. Otherwise, if an error
12457 ** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew)
12460 SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew);
12463 ** CAPI3REF: Configure a changeset rebaser object.
12466 ** Configure the changeset rebaser object to rebase changesets according
12467 ** to the conflict resolutions described by buffer pRebase (size nRebase
12468 ** bytes), which must have been obtained from a previous call to
12469 ** sqlite3changeset_apply_v2().
12471 SQLITE_API int sqlite3rebaser_configure(
12473 int nRebase, const void *pRebase
12477 ** CAPI3REF: Rebase a changeset
12480 ** Argument pIn must point to a buffer containing a changeset nIn bytes
12481 ** in size. This function allocates and populates a buffer with a copy
12482 ** of the changeset rebased according to the configuration of the
12483 ** rebaser object passed as the first argument. If successful, (*ppOut)
12484 ** is set to point to the new buffer containing the rebased changeset and
12485 ** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the
12486 ** responsibility of the caller to eventually free the new buffer using
12487 ** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut)
12488 ** are set to zero and an SQLite error code returned.
12490 SQLITE_API int sqlite3rebaser_rebase(
12492 int nIn, const void *pIn,
12493 int *pnOut, void **ppOut
12497 ** CAPI3REF: Delete a changeset rebaser object.
12500 ** Delete the changeset rebaser object and all associated resources. There
12501 ** should be one call to this function for each successful invocation
12502 ** of sqlite3rebaser_create().
12504 SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p);
12507 ** CAPI3REF: Streaming Versions of API functions.
12509 ** The six streaming API xxx_strm() functions serve similar purposes to the
12510 ** corresponding non-streaming API functions:
12512 ** <table border=1 style="margin-left:8ex;margin-right:8ex">
12513 ** <tr><th>Streaming function<th>Non-streaming equivalent</th>
12514 ** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply]
12515 ** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2]
12516 ** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat]
12517 ** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert]
12518 ** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start]
12519 ** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset]
12520 ** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset]
12523 ** Non-streaming functions that accept changesets (or patchsets) as input
12524 ** require that the entire changeset be stored in a single buffer in memory.
12525 ** Similarly, those that return a changeset or patchset do so by returning
12526 ** a pointer to a single large buffer allocated using sqlite3_malloc().
12527 ** Normally this is convenient. However, if an application running in a
12528 ** low-memory environment is required to handle very large changesets, the
12529 ** large contiguous memory allocations required can become onerous.
12531 ** In order to avoid this problem, instead of a single large buffer, input
12532 ** is passed to a streaming API functions by way of a callback function that
12533 ** the sessions module invokes to incrementally request input data as it is
12534 ** required. In all cases, a pair of API function parameters such as
12537 ** int nChangeset,
12538 ** void *pChangeset,
12544 ** int (*xInput)(void *pIn, void *pData, int *pnData),
12545 ** void *pIn,
12548 ** Each time the xInput callback is invoked by the sessions module, the first
12549 ** argument passed is a copy of the supplied pIn context pointer. The second
12550 ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no
12551 ** error occurs the xInput method should copy up to (*pnData) bytes of data
12552 ** into the buffer and set (*pnData) to the actual number of bytes copied
12553 ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData)
12554 ** should be set to zero to indicate this. Or, if an error occurs, an SQLite
12555 ** error code should be returned. In all cases, if an xInput callback returns
12556 ** an error, all processing is abandoned and the streaming API function
12557 ** returns a copy of the error code to the caller.
12559 ** In the case of sqlite3changeset_start_strm(), the xInput callback may be
12560 ** invoked by the sessions module at any point during the lifetime of the
12561 ** iterator. If such an xInput callback returns an error, the iterator enters
12562 ** an error state, whereby all subsequent calls to iterator functions
12563 ** immediately fail with the same error code as returned by xInput.
12565 ** Similarly, streaming API functions that return changesets (or patchsets)
12566 ** return them in chunks by way of a callback function instead of via a
12567 ** pointer to a single large buffer. In this case, a pair of parameters such
12571 ** int *pnChangeset,
12572 ** void **ppChangeset,
12578 ** int (*xOutput)(void *pOut, const void *pData, int nData),
12579 ** void *pOut
12582 ** The xOutput callback is invoked zero or more times to return data to
12583 ** the application. The first parameter passed to each call is a copy of the
12584 ** pOut pointer supplied by the application. The second parameter, pData,
12585 ** points to a buffer nData bytes in size containing the chunk of output
12586 ** data being returned. If the xOutput callback successfully processes the
12587 ** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
12588 ** it should return some other SQLite error code. In this case processing
12589 ** is immediately abandoned and the streaming API function returns a copy
12590 ** of the xOutput error code to the application.
12592 ** The sessions module never invokes an xOutput callback with the third
12593 ** parameter set to a value less than or equal to zero. Other than this,
12594 ** no guarantees are made as to the size of the chunks of data returned.
12596 SQLITE_API int sqlite3changeset_apply_strm(
12597 sqlite3 *db, /* Apply change to "main" db of this handle */
12598 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
12599 void *pIn, /* First arg for xInput */
12601 void *pCtx, /* Copy of sixth arg to _apply() */
12602 const char *zTab /* Table name */
12605 void *pCtx, /* Copy of sixth arg to _apply() */
12606 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12607 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12609 void *pCtx /* First argument passed to xConflict */
12611 SQLITE_API int sqlite3changeset_apply_v2_strm(
12612 sqlite3 *db, /* Apply change to "main" db of this handle */
12613 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
12614 void *pIn, /* First arg for xInput */
12616 void *pCtx, /* Copy of sixth arg to _apply() */
12617 const char *zTab /* Table name */
12620 void *pCtx, /* Copy of sixth arg to _apply() */
12621 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12622 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12624 void *pCtx, /* First argument passed to xConflict */
12625 void **ppRebase, int *pnRebase,
12628 SQLITE_API int sqlite3changeset_concat_strm(
12629 int (*xInputA)(void *pIn, void *pData, int *pnData),
12631 int (*xInputB)(void *pIn, void *pData, int *pnData),
12633 int (*xOutput)(void *pOut, const void *pData, int nData),
12636 SQLITE_API int sqlite3changeset_invert_strm(
12637 int (*xInput)(void *pIn, void *pData, int *pnData),
12639 int (*xOutput)(void *pOut, const void *pData, int nData),
12642 SQLITE_API int sqlite3changeset_start_strm(
12643 sqlite3_changeset_iter **pp,
12644 int (*xInput)(void *pIn, void *pData, int *pnData),
12647 SQLITE_API int sqlite3changeset_start_v2_strm(
12648 sqlite3_changeset_iter **pp,
12649 int (*xInput)(void *pIn, void *pData, int *pnData),
12653 SQLITE_API int sqlite3session_changeset_strm(
12654 sqlite3_session *pSession,
12655 int (*xOutput)(void *pOut, const void *pData, int nData),
12658 SQLITE_API int sqlite3session_patchset_strm(
12659 sqlite3_session *pSession,
12660 int (*xOutput)(void *pOut, const void *pData, int nData),
12663 SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*,
12664 int (*xInput)(void *pIn, void *pData, int *pnData),
12667 SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*,
12668 int (*xOutput)(void *pOut, const void *pData, int nData),
12671 SQLITE_API int sqlite3rebaser_rebase_strm(
12672 sqlite3_rebaser *pRebaser,
12673 int (*xInput)(void *pIn, void *pData, int *pnData),
12675 int (*xOutput)(void *pOut, const void *pData, int nData),
12680 ** CAPI3REF: Configure global parameters
12682 ** The sqlite3session_config() interface is used to make global configuration
12683 ** changes to the sessions module in order to tune it to the specific needs
12684 ** of the application.
12686 ** The sqlite3session_config() interface is not threadsafe. If it is invoked
12687 ** while any other thread is inside any other sessions method then the
12688 ** results are undefined. Furthermore, if it is invoked after any sessions
12689 ** related objects have been created, the results are also undefined.
12691 ** The first argument to the sqlite3session_config() function must be one
12692 ** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The
12693 ** interpretation of the (void*) value passed as the second parameter and
12694 ** the effect of calling this function depends on the value of the first
12698 ** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd>
12699 ** By default, the sessions module streaming interfaces attempt to input
12700 ** and output data in approximately 1 KiB chunks. This operand may be used
12701 ** to set and query the value of this configuration setting. The pointer
12702 ** passed as the second argument must point to a value of type (int).
12703 ** If this value is greater than 0, it is used as the new streaming data
12704 ** chunk size for both input and output. Before returning, the (int) value
12705 ** pointed to by pArg is set to the final value of the streaming interface
12709 ** This function returns SQLITE_OK if successful, or an SQLite error code
12712 SQLITE_API int sqlite3session_config(int op, void *pArg);
12715 ** CAPI3REF: Values for sqlite3session_config().
12717 #define SQLITE_SESSION_CONFIG_STRMSIZE 1
12720 ** Make sure we can call this stuff from C++.
12726 #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
12728 /******** End of sqlite3session.h *********/
12729 /******** Begin file fts5.h *********/
12733 ** The author disclaims copyright to this source code. In place of
12734 ** a legal notice, here is a blessing:
12736 ** May you do good and not evil.
12737 ** May you find forgiveness for yourself and forgive others.
12738 ** May you share freely, never taking more than you give.
12740 ******************************************************************************
12742 ** Interfaces to extend FTS5. Using the interfaces defined in this file,
12743 ** FTS5 may be extended with:
12745 ** * custom tokenizers, and
12746 ** * custom auxiliary functions.
12758 /*************************************************************************
12759 ** CUSTOM AUXILIARY FUNCTIONS
12761 ** Virtual table implementations may overload SQL functions by implementing
12762 ** the sqlite3_module.xFindFunction() method.
12765 typedef struct Fts5ExtensionApi Fts5ExtensionApi;
12766 typedef struct Fts5Context Fts5Context;
12767 typedef struct Fts5PhraseIter Fts5PhraseIter;
12769 typedef void (*fts5_extension_function)(
12770 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
12771 Fts5Context *pFts, /* First arg to pass to pApi functions */
12772 sqlite3_context *pCtx, /* Context for returning result/error */
12773 int nVal, /* Number of values in apVal[] array */
12774 sqlite3_value **apVal /* Array of trailing arguments */
12777 struct Fts5PhraseIter {
12778 const unsigned char *a;
12779 const unsigned char *b;
12783 ** EXTENSION API FUNCTIONS
12785 ** xUserData(pFts):
12786 ** Return a copy of the context pointer the extension function was
12787 ** registered with.
12789 ** xColumnTotalSize(pFts, iCol, pnToken):
12790 ** If parameter iCol is less than zero, set output variable *pnToken
12791 ** to the total number of tokens in the FTS5 table. Or, if iCol is
12792 ** non-negative but less than the number of columns in the table, return
12793 ** the total number of tokens in column iCol, considering all rows in
12796 ** If parameter iCol is greater than or equal to the number of columns
12797 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
12798 ** an OOM condition or IO error), an appropriate SQLite error code is
12801 ** xColumnCount(pFts):
12802 ** Return the number of columns in the table.
12804 ** xColumnSize(pFts, iCol, pnToken):
12805 ** If parameter iCol is less than zero, set output variable *pnToken
12806 ** to the total number of tokens in the current row. Or, if iCol is
12807 ** non-negative but less than the number of columns in the table, set
12808 ** *pnToken to the number of tokens in column iCol of the current row.
12810 ** If parameter iCol is greater than or equal to the number of columns
12811 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
12812 ** an OOM condition or IO error), an appropriate SQLite error code is
12815 ** This function may be quite inefficient if used with an FTS5 table
12816 ** created with the "columnsize=0" option.
12819 ** If parameter iCol is less than zero, or greater than or equal to the
12820 ** number of columns in the table, SQLITE_RANGE is returned.
12822 ** Otherwise, this function attempts to retrieve the text of column iCol of
12823 ** the current document. If successful, (*pz) is set to point to a buffer
12824 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes
12825 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
12826 ** if an error occurs, an SQLite error code is returned and the final values
12827 ** of (*pz) and (*pn) are undefined.
12830 ** Returns the number of phrases in the current query expression.
12833 ** If parameter iCol is less than zero, or greater than or equal to the
12834 ** number of phrases in the current query, as returned by xPhraseCount,
12835 ** 0 is returned. Otherwise, this function returns the number of tokens in
12836 ** phrase iPhrase of the query. Phrases are numbered starting from zero.
12839 ** Set *pnInst to the total number of occurrences of all phrases within
12840 ** the query within the current row. Return SQLITE_OK if successful, or
12841 ** an error code (i.e. SQLITE_NOMEM) if an error occurs.
12843 ** This API can be quite slow if used with an FTS5 table created with the
12844 ** "detail=none" or "detail=column" option. If the FTS5 table is created
12845 ** with either "detail=none" or "detail=column" and "content=" option
12846 ** (i.e. if it is a contentless table), then this API always returns 0.
12849 ** Query for the details of phrase match iIdx within the current row.
12850 ** Phrase matches are numbered starting from zero, so the iIdx argument
12851 ** should be greater than or equal to zero and smaller than the value
12852 ** output by xInstCount(). If iIdx is less than zero or greater than
12853 ** or equal to the value returned by xInstCount(), SQLITE_RANGE is returned.
12855 ** Otherwise, output parameter *piPhrase is set to the phrase number, *piCol
12856 ** to the column in which it occurs and *piOff the token offset of the
12857 ** first token of the phrase. SQLITE_OK is returned if successful, or an
12858 ** error code (i.e. SQLITE_NOMEM) if an error occurs.
12860 ** This API can be quite slow if used with an FTS5 table created with the
12861 ** "detail=none" or "detail=column" option.
12864 ** Returns the rowid of the current row.
12867 ** Tokenize text using the tokenizer belonging to the FTS5 table.
12869 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
12870 ** This API function is used to query the FTS table for phrase iPhrase
12871 ** of the current query. Specifically, a query equivalent to:
12873 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
12875 ** with $p set to a phrase equivalent to the phrase iPhrase of the
12876 ** current query is executed. Any column filter that applies to
12877 ** phrase iPhrase of the current query is included in $p. For each
12878 ** row visited, the callback function passed as the fourth argument
12879 ** is invoked. The context and API objects passed to the callback
12880 ** function may be used to access the properties of each matched row.
12881 ** Invoking Api.xUserData() returns a copy of the pointer passed as
12882 ** the third argument to pUserData.
12884 ** If parameter iPhrase is less than zero, or greater than or equal to
12885 ** the number of phrases in the query, as returned by xPhraseCount(),
12886 ** this function returns SQLITE_RANGE.
12888 ** If the callback function returns any value other than SQLITE_OK, the
12889 ** query is abandoned and the xQueryPhrase function returns immediately.
12890 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
12891 ** Otherwise, the error code is propagated upwards.
12893 ** If the query runs to completion without incident, SQLITE_OK is returned.
12894 ** Or, if some error occurs before the query completes or is aborted by
12895 ** the callback, an SQLite error code is returned.
12898 ** xSetAuxdata(pFts5, pAux, xDelete)
12900 ** Save the pointer passed as the second argument as the extension function's
12901 ** "auxiliary data". The pointer may then be retrieved by the current or any
12902 ** future invocation of the same fts5 extension function made as part of
12903 ** the same MATCH query using the xGetAuxdata() API.
12905 ** Each extension function is allocated a single auxiliary data slot for
12906 ** each FTS query (MATCH expression). If the extension function is invoked
12907 ** more than once for a single FTS query, then all invocations share a
12908 ** single auxiliary data context.
12910 ** If there is already an auxiliary data pointer when this function is
12911 ** invoked, then it is replaced by the new pointer. If an xDelete callback
12912 ** was specified along with the original pointer, it is invoked at this
12915 ** The xDelete callback, if one is specified, is also invoked on the
12916 ** auxiliary data pointer after the FTS5 query has finished.
12918 ** If an error (e.g. an OOM condition) occurs within this function,
12919 ** the auxiliary data is set to NULL and an error code returned. If the
12920 ** xDelete parameter was not NULL, it is invoked on the auxiliary data
12921 ** pointer before returning.
12924 ** xGetAuxdata(pFts5, bClear)
12926 ** Returns the current auxiliary data pointer for the fts5 extension
12927 ** function. See the xSetAuxdata() method for details.
12929 ** If the bClear argument is non-zero, then the auxiliary data is cleared
12930 ** (set to NULL) before this function returns. In this case the xDelete,
12931 ** if any, is not invoked.
12934 ** xRowCount(pFts5, pnRow)
12936 ** This function is used to retrieve the total number of rows in the table.
12937 ** In other words, the same value that would be returned by:
12939 ** SELECT count(*) FROM ftstable;
12942 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext
12943 ** method, to iterate through all instances of a single query phrase within
12944 ** the current row. This is the same information as is accessible via the
12945 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
12946 ** to use, this API may be faster under some circumstances. To iterate
12947 ** through instances of phrase iPhrase, use the following code:
12949 ** Fts5PhraseIter iter;
12951 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
12953 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
12955 ** // An instance of phrase iPhrase at offset iOff of column iCol
12958 ** The Fts5PhraseIter structure is defined above. Applications should not
12959 ** modify this structure directly - it should only be used as shown above
12960 ** with the xPhraseFirst() and xPhraseNext() API methods (and by
12961 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
12963 ** This API can be quite slow if used with an FTS5 table created with the
12964 ** "detail=none" or "detail=column" option. If the FTS5 table is created
12965 ** with either "detail=none" or "detail=column" and "content=" option
12966 ** (i.e. if it is a contentless table), then this API always iterates
12967 ** through an empty set (all calls to xPhraseFirst() set iCol to -1).
12970 ** See xPhraseFirst above.
12972 ** xPhraseFirstColumn()
12973 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst()
12974 ** and xPhraseNext() APIs described above. The difference is that instead
12975 ** of iterating through all instances of a phrase in the current row, these
12976 ** APIs are used to iterate through the set of columns in the current row
12977 ** that contain one or more instances of a specified phrase. For example:
12979 ** Fts5PhraseIter iter;
12981 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
12983 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol)
12985 ** // Column iCol contains at least one instance of phrase iPhrase
12988 ** This API can be quite slow if used with an FTS5 table created with the
12989 ** "detail=none" option. If the FTS5 table is created with either
12990 ** "detail=none" "content=" option (i.e. if it is a contentless table),
12991 ** then this API always iterates through an empty set (all calls to
12992 ** xPhraseFirstColumn() set iCol to -1).
12994 ** The information accessed using this API and its companion
12995 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
12996 ** (or xInst/xInstCount). The chief advantage of this API is that it is
12997 ** significantly more efficient than those alternatives when used with
12998 ** "detail=column" tables.
13000 ** xPhraseNextColumn()
13001 ** See xPhraseFirstColumn above.
13003 ** xQueryToken(pFts5, iPhrase, iToken, ppToken, pnToken)
13004 ** This is used to access token iToken of phrase iPhrase of the current
13005 ** query. Before returning, output parameter *ppToken is set to point
13006 ** to a buffer containing the requested token, and *pnToken to the
13007 ** size of this buffer in bytes.
13009 ** If iPhrase or iToken are less than zero, or if iPhrase is greater than
13010 ** or equal to the number of phrases in the query as reported by
13011 ** xPhraseCount(), or if iToken is equal to or greater than the number of
13012 ** tokens in the phrase, SQLITE_RANGE is returned and *ppToken and *pnToken
13015 ** The output text is not a copy of the query text that specified the
13016 ** token. It is the output of the tokenizer module. For tokendata=1
13017 ** tables, this includes any embedded 0x00 and trailing data.
13019 ** xInstToken(pFts5, iIdx, iToken, ppToken, pnToken)
13020 ** This is used to access token iToken of phrase hit iIdx within the
13021 ** current row. If iIdx is less than zero or greater than or equal to the
13022 ** value returned by xInstCount(), SQLITE_RANGE is returned. Otherwise,
13023 ** output variable (*ppToken) is set to point to a buffer containing the
13024 ** matching document token, and (*pnToken) to the size of that buffer in
13025 ** bytes. This API is not available if the specified token matches a
13026 ** prefix query term. In that case both output variables are always set
13029 ** The output text is not a copy of the document text that was tokenized.
13030 ** It is the output of the tokenizer module. For tokendata=1 tables, this
13031 ** includes any embedded 0x00 and trailing data.
13033 ** This API can be quite slow if used with an FTS5 table created with the
13034 ** "detail=none" or "detail=column" option.
13036 struct Fts5ExtensionApi {
13037 int iVersion; /* Currently always set to 3 */
13039 void *(*xUserData)(Fts5Context*);
13041 int (*xColumnCount)(Fts5Context*);
13042 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
13043 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
13045 int (*xTokenize)(Fts5Context*,
13046 const char *pText, int nText, /* Text to tokenize */
13047 void *pCtx, /* Context passed to xToken() */
13048 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
13051 int (*xPhraseCount)(Fts5Context*);
13052 int (*xPhraseSize)(Fts5Context*, int iPhrase);
13054 int (*xInstCount)(Fts5Context*, int *pnInst);
13055 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
13057 sqlite3_int64 (*xRowid)(Fts5Context*);
13058 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
13059 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
13061 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
13062 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
13064 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
13065 void *(*xGetAuxdata)(Fts5Context*, int bClear);
13067 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
13068 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
13070 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
13071 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
13073 /* Below this point are iVersion>=3 only */
13074 int (*xQueryToken)(Fts5Context*,
13075 int iPhrase, int iToken,
13076 const char **ppToken, int *pnToken
13078 int (*xInstToken)(Fts5Context*, int iIdx, int iToken, const char**, int*);
13082 ** CUSTOM AUXILIARY FUNCTIONS
13083 *************************************************************************/
13085 /*************************************************************************
13086 ** CUSTOM TOKENIZERS
13088 ** Applications may also register custom tokenizer types. A tokenizer
13089 ** is registered by providing fts5 with a populated instance of the
13090 ** following structure. All structure methods must be defined, setting
13091 ** any member of the fts5_tokenizer struct to NULL leads to undefined
13092 ** behaviour. The structure methods are expected to function as follows:
13095 ** This function is used to allocate and initialize a tokenizer instance.
13096 ** A tokenizer instance is required to actually tokenize text.
13098 ** The first argument passed to this function is a copy of the (void*)
13099 ** pointer provided by the application when the fts5_tokenizer object
13100 ** was registered with FTS5 (the third argument to xCreateTokenizer()).
13101 ** The second and third arguments are an array of nul-terminated strings
13102 ** containing the tokenizer arguments, if any, specified following the
13103 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used
13104 ** to create the FTS5 table.
13106 ** The final argument is an output variable. If successful, (*ppOut)
13107 ** should be set to point to the new tokenizer handle and SQLITE_OK
13108 ** returned. If an error occurs, some value other than SQLITE_OK should
13109 ** be returned. In this case, fts5 assumes that the final value of *ppOut
13113 ** This function is invoked to delete a tokenizer handle previously
13114 ** allocated using xCreate(). Fts5 guarantees that this function will
13115 ** be invoked exactly once for each successful call to xCreate().
13118 ** This function is expected to tokenize the nText byte string indicated
13119 ** by argument pText. pText may or may not be nul-terminated. The first
13120 ** argument passed to this function is a pointer to an Fts5Tokenizer object
13121 ** returned by an earlier call to xCreate().
13123 ** The second argument indicates the reason that FTS5 is requesting
13124 ** tokenization of the supplied text. This is always one of the following
13127 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
13128 ** or removed from the FTS table. The tokenizer is being invoked to
13129 ** determine the set of tokens to add to (or delete from) the
13132 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed
13133 ** against the FTS index. The tokenizer is being called to tokenize
13134 ** a bareword or quoted string specified as part of the query.
13136 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
13137 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
13138 ** followed by a "*" character, indicating that the last token
13139 ** returned by the tokenizer will be treated as a token prefix.
13141 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
13142 ** satisfy an fts5_api.xTokenize() request made by an auxiliary
13143 ** function. Or an fts5_api.xColumnSize() request made by the same
13144 ** on a columnsize=0 database.
13147 ** For each token in the input string, the supplied callback xToken() must
13148 ** be invoked. The first argument to it should be a copy of the pointer
13149 ** passed as the second argument to xTokenize(). The third and fourth
13150 ** arguments are a pointer to a buffer containing the token text, and the
13151 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets
13152 ** of the first byte of and first byte immediately following the text from
13153 ** which the token is derived within the input.
13155 ** The second argument passed to the xToken() callback ("tflags") should
13156 ** normally be set to 0. The exception is if the tokenizer supports
13157 ** synonyms. In this case see the discussion below for details.
13159 ** FTS5 assumes the xToken() callback is invoked for each token in the
13160 ** order that they occur within the input text.
13162 ** If an xToken() callback returns any value other than SQLITE_OK, then
13163 ** the tokenization should be abandoned and the xTokenize() method should
13164 ** immediately return a copy of the xToken() return value. Or, if the
13165 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
13166 ** if an error occurs with the xTokenize() implementation itself, it
13167 ** may abandon the tokenization and return any error code other than
13168 ** SQLITE_OK or SQLITE_DONE.
13172 ** Custom tokenizers may also support synonyms. Consider a case in which a
13173 ** user wishes to query for a phrase such as "first place". Using the
13174 ** built-in tokenizers, the FTS5 query 'first + place' will match instances
13175 ** of "first place" within the document set, but not alternative forms
13176 ** such as "1st place". In some applications, it would be better to match
13177 ** all instances of "first place" or "1st place" regardless of which form
13178 ** the user specified in the MATCH query text.
13180 ** There are several ways to approach this in FTS5:
13182 ** <ol><li> By mapping all synonyms to a single token. In this case, using
13183 ** the above example, this means that the tokenizer returns the
13184 ** same token for inputs "first" and "1st". Say that token is in
13185 ** fact "first", so that when the user inserts the document "I won
13186 ** 1st place" entries are added to the index for tokens "i", "won",
13187 ** "first" and "place". If the user then queries for '1st + place',
13188 ** the tokenizer substitutes "first" for "1st" and the query works
13191 ** <li> By querying the index for all synonyms of each query term
13192 ** separately. In this case, when tokenizing query text, the
13193 ** tokenizer may provide multiple synonyms for a single term
13194 ** within the document. FTS5 then queries the index for each
13195 ** synonym individually. For example, faced with the query:
13198 ** ... MATCH 'first place'</codeblock>
13200 ** the tokenizer offers both "1st" and "first" as synonyms for the
13201 ** first token in the MATCH query and FTS5 effectively runs a query
13205 ** ... MATCH '(first OR 1st) place'</codeblock>
13207 ** except that, for the purposes of auxiliary functions, the query
13208 ** still appears to contain just two phrases - "(first OR 1st)"
13209 ** being treated as a single phrase.
13211 ** <li> By adding multiple synonyms for a single term to the FTS index.
13212 ** Using this method, when tokenizing document text, the tokenizer
13213 ** provides multiple synonyms for each token. So that when a
13214 ** document such as "I won first place" is tokenized, entries are
13215 ** added to the FTS index for "i", "won", "first", "1st" and
13218 ** This way, even if the tokenizer does not provide synonyms
13219 ** when tokenizing query text (it should not - to do so would be
13220 ** inefficient), it doesn't matter if the user queries for
13221 ** 'first + place' or '1st + place', as there are entries in the
13222 ** FTS index corresponding to both forms of the first token.
13225 ** Whether it is parsing document or query text, any call to xToken that
13226 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
13227 ** is considered to supply a synonym for the previous token. For example,
13228 ** when parsing the document "I won first place", a tokenizer that supports
13229 ** synonyms would call xToken() 5 times, as follows:
13232 ** xToken(pCtx, 0, "i", 1, 0, 1);
13233 ** xToken(pCtx, 0, "won", 3, 2, 5);
13234 ** xToken(pCtx, 0, "first", 5, 6, 11);
13235 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11);
13236 ** xToken(pCtx, 0, "place", 5, 12, 17);
13239 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
13240 ** xToken() is called. Multiple synonyms may be specified for a single token
13241 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence.
13242 ** There is no limit to the number of synonyms that may be provided for a
13245 ** In many cases, method (1) above is the best approach. It does not add
13246 ** extra data to the FTS index or require FTS5 to query for multiple terms,
13247 ** so it is efficient in terms of disk space and query speed. However, it
13248 ** does not support prefix queries very well. If, as suggested above, the
13249 ** token "first" is substituted for "1st" by the tokenizer, then the query:
13252 ** ... MATCH '1s*'</codeblock>
13254 ** will not match documents that contain the token "1st" (as the tokenizer
13255 ** will probably not map "1s" to any prefix of "first").
13257 ** For full prefix support, method (3) may be preferred. In this case,
13258 ** because the index contains entries for both "first" and "1st", prefix
13259 ** queries such as 'fi*' or '1s*' will match correctly. However, because
13260 ** extra entries are added to the FTS index, this method uses more space
13261 ** within the database.
13263 ** Method (2) offers a midpoint between (1) and (3). Using this method,
13264 ** a query such as '1s*' will match documents that contain the literal
13265 ** token "1st", but not "first" (assuming the tokenizer is not able to
13266 ** provide synonyms for prefixes). However, a non-prefix query like '1st'
13267 ** will match against "1st" and "first". This method does not require
13268 ** extra disk space, as no extra entries are added to the FTS index.
13269 ** On the other hand, it may require more CPU cycles to run MATCH queries,
13270 ** as separate queries of the FTS index are required for each synonym.
13272 ** When using methods (2) or (3), it is important that the tokenizer only
13273 ** provide synonyms when tokenizing document text (method (3)) or query
13274 ** text (method (2)), not both. Doing so will not cause any errors, but is
13277 typedef struct Fts5Tokenizer Fts5Tokenizer;
13278 typedef struct fts5_tokenizer fts5_tokenizer;
13279 struct fts5_tokenizer {
13280 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
13281 void (*xDelete)(Fts5Tokenizer*);
13282 int (*xTokenize)(Fts5Tokenizer*,
13284 int flags, /* Mask of FTS5_TOKENIZE_* flags */
13285 const char *pText, int nText,
13287 void *pCtx, /* Copy of 2nd argument to xTokenize() */
13288 int tflags, /* Mask of FTS5_TOKEN_* flags */
13289 const char *pToken, /* Pointer to buffer containing token */
13290 int nToken, /* Size of token in bytes */
13291 int iStart, /* Byte offset of token within input text */
13292 int iEnd /* Byte offset of end of token within input text */
13297 /* Flags that may be passed as the third argument to xTokenize() */
13298 #define FTS5_TOKENIZE_QUERY 0x0001
13299 #define FTS5_TOKENIZE_PREFIX 0x0002
13300 #define FTS5_TOKENIZE_DOCUMENT 0x0004
13301 #define FTS5_TOKENIZE_AUX 0x0008
13303 /* Flags that may be passed by the tokenizer implementation back to FTS5
13304 ** as the third argument to the supplied xToken callback. */
13305 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */
13308 ** END OF CUSTOM TOKENIZERS
13309 *************************************************************************/
13311 /*************************************************************************
13312 ** FTS5 EXTENSION REGISTRATION API
13314 typedef struct fts5_api fts5_api;
13316 int iVersion; /* Currently always set to 2 */
13318 /* Create a new tokenizer */
13319 int (*xCreateTokenizer)(
13323 fts5_tokenizer *pTokenizer,
13324 void (*xDestroy)(void*)
13327 /* Find an existing tokenizer */
13328 int (*xFindTokenizer)(
13332 fts5_tokenizer *pTokenizer
13335 /* Create a new auxiliary function */
13336 int (*xCreateFunction)(
13340 fts5_extension_function xFunction,
13341 void (*xDestroy)(void*)
13346 ** END OF REGISTRATION API
13347 *************************************************************************/
13350 } /* end of the 'extern "C"' block */
13353 #endif /* _FTS5_H */
13355 /******** End of fts5.h *********/