<?php
/* vim: set expandtab tabstop=4 shiftwidth=4 foldmethod=marker: */
// +----------------------------------------------------------------------+
// | PHP Version 4                                                        |
// +----------------------------------------------------------------------+
// | Copyright (c) 1997-2004 The PHP Group                                |
// +----------------------------------------------------------------------+
// | This source file is subject to version 2.02 of the PHP license,      |
// | that is bundled with this package in the file LICENSE, and is        |
// | available at through the world-wide-web at                           |
// | http://www.php.net/license/2_02.txt.                                 |
// | If you did not receive a copy of the PHP license and are unable to   |
// | obtain it through the world-wide-web, please send a note to          |
// | license@php.net so we can mail you a copy immediately.               |
// +----------------------------------------------------------------------+
// | Authors: Sterling Hughes <sterling@php.net>                          |
// |          Antônio Carlos Venâncio Júnior <floripa@php.net>            |
// | Maintainer: Daniel Convissor <danielc@php.net>                       |
// +----------------------------------------------------------------------+
//
// $Id$


// TODO
//    - This driver may fail with multiple connections under the same
//      user/pass/host and different databases


require_once 'DB/common.php';

/**
 * Database independent query interface definition for PHP's Sybase
 * extension.
 *
 * @package  DB
 * @version  $Id$
 * @category Database
 * @author   Sterling Hughes <sterling@php.net>
 * @author   Antônio Carlos Venâncio Júnior <floripa@php.net>
 */
class DB_sybase extends DB_common
{
    // {{{ properties

    var $connection;
    var $phptype, $dbsyntax;
    var $prepare_tokens = array();
    var $prepare_types = array();
    var $transaction_opcount = 0;
    var $autocommit = true;

    // }}}
    // {{{ constructor

    /**
     * DB_sybase constructor.
     *
     * @access public
     */
    function DB_sybase()
    {
        $this->DB_common();
        $this->phptype = 'sybase';
        $this->dbsyntax = 'sybase';
        $this->features = array(
            'prepare' => false,
            'pconnect' => true,
            'transactions' => false,
            'limit' => 'emulate'
        );
        $this->errorcode_map = array(
        );
    }

    // }}}
    // {{{ connect()

    /**
     * Connect to a database and log in as the specified user.
     *
     * @param $dsn the data source name (see DB::parseDSN for syntax)
     * @param $persistent (optional) whether the connection should
     *        be persistent
     * @access public
     * @return int DB_OK on success, a DB error on failure
     */
    function connect($dsninfo, $persistent = false)
    {
        if (!DB::assertExtension('sybase') &&
            !DB::assertExtension('sybase_ct'))
        {
            return $this->raiseError(DB_ERROR_EXTENSION_NOT_FOUND);
        }

        $this->dsn = $dsninfo;

        $interface = $dsninfo['hostspec'] ? $dsninfo['hostspec'] : 'localhost';
        $connect_function = $persistent ? 'sybase_pconnect' : 'sybase_connect';

        if ($interface && $dsninfo['username'] && $dsninfo['password']) {
            $conn = @$connect_function($interface, $dsninfo['username'],
                                       $dsninfo['password']);
        } elseif ($interface && $dsninfo['username']) {
            /*
             * Using false for pw as a workaround to avoid segfault.
             * See PEAR bug 631
             */
            $conn = @$connect_function($interface, $dsninfo['username'],
                                       false);
        } else {
            $conn = false;
        }

        if (!$conn) {
            return $this->raiseError(DB_ERROR_CONNECT_FAILED);
        }

        if ($dsninfo['database']) {
            if (!@sybase_select_db($dsninfo['database'], $conn)) {
                return $this->raiseError(DB_ERROR_NODBSELECTED, null,
                                         null, null, @sybase_get_last_message());
            }
            $this->_db = $dsninfo['database'];
        }

        $this->connection = $conn;
        return DB_OK;
    }

    // }}}
    // {{{ disconnect()

    /**
     * Log out and disconnect from the database.
     *
     * @access public
     *
     * @return bool true on success, false if not connected.
     */
    function disconnect()
    {
        $ret = @sybase_close($this->connection);
        $this->connection = null;
        return $ret;
    }

    // }}}
    // {{{ errorNative()

    /**
     * Get the last server error messge (if any)
     *
     * @return string sybase last error message
     */
    function errorNative()
    {
        return @sybase_get_last_message();
    }

    // }}}
    // {{{ errorCode()

    /**
     * Determine PEAR::DB error code from the database's text error message.
     *
     * @param  string  $errormsg  error message returned from the database
     * @return integer  an error number from a DB error constant
     */
    function errorCode($errormsg)
    {
        static $error_regexps;
        if (!isset($error_regexps)) {
            $error_regexps = array(
                '/Incorrect syntax near/'
                    => DB_ERROR_SYNTAX,
                '/^Unclosed quote before the character string [\"\'].*[\"\']\./'
                    => DB_ERROR_SYNTAX,
                '/Implicit conversion from datatype [\"\'].+[\"\'] to [\"\'].+[\"\'] is not allowed\./'
                    => DB_ERROR_INVALID_NUMBER,
                '/Cannot drop the table [\"\'].+[\"\'], because it doesn\'t exist in the system catalogs\./'
                    => DB_ERROR_NOSUCHTABLE,
                '/Only the owner of object [\"\'].+[\"\'] or a user with System Administrator \(SA\) role can run this command\./'
                    => DB_ERROR_ACCESS_VIOLATION,
                '/^.+ permission denied on object .+, database .+, owner .+/'
                    => DB_ERROR_ACCESS_VIOLATION,
                '/^.* permission denied, database .+, owner .+/'
                    => DB_ERROR_ACCESS_VIOLATION,
                '/[^.*] not found\./'
                    => DB_ERROR_NOSUCHTABLE,
                '/There is already an object named/'
                    => DB_ERROR_ALREADY_EXISTS,
                '/Invalid column name/'
                    => DB_ERROR_NOSUCHFIELD,
                '/does not allow null values/'
                    => DB_ERROR_CONSTRAINT_NOT_NULL,
                '/Command has been aborted/'
                    => DB_ERROR_CONSTRAINT,
            );
        }

        foreach ($error_regexps as $regexp => $code) {
            if (preg_match($regexp, $errormsg)) {
                return $code;
            }
        }
        return DB_ERROR;
    }

    // }}}
    // {{{ sybaseRaiseError()

    /**
     * Gather information about an error, then use that info to create a
     * DB error object and finally return that object.
     *
     * @param  integer  $errno  PEAR error number (usually a DB constant) if
     *                          manually raising an error
     * @return object  DB error object
     * @see errorNative()
     * @see errorCode()
     * @see DB_common::raiseError()
     */
    function sybaseRaiseError($errno = null)
    {
        $native = $this->errorNative();
        if ($errno === null) {
            $errno = $this->errorCode($native);
        }
        return $this->raiseError($errno, null, null, null, $native);
    }

    // }}}
    // {{{ simpleQuery()

    /**
     * Send a query to Sybase and return the results as a Sybase resource
     * identifier.
     *
     * @param the SQL query
     *
     * @access public
     *
     * @return mixed returns a valid Sybase result for successful SELECT
     * queries, DB_OK for other successful queries.  A DB error is
     * returned on failure.
     */
    function simpleQuery($query)
    {
        $ismanip = DB::isManip($query);
        $this->last_query = $query;
        if (!@sybase_select_db($this->_db, $this->connection)) {
            return $this->sybaseRaiseError(DB_ERROR_NODBSELECTED);
        }
        $query = $this->modifyQuery($query);
        if (!$this->autocommit && $ismanip) {
            if ($this->transaction_opcount == 0) {
                $result = @sybase_query('BEGIN TRANSACTION', $this->connection);
                if (!$result) {
                    return $this->sybaseRaiseError();
                }
            }
            $this->transaction_opcount++;
        }
        $result = @sybase_query($query, $this->connection);
        if (!$result) {
            return $this->sybaseRaiseError();
        }
        if (is_resource($result)) {
            $numrows = $this->numRows($result);
            if (is_object($numrows)) {
                return $numrows;
            }
            $this->num_rows[(int)$result] = $numrows;
            return $result;
        }
        // Determine which queries that should return data, and which
        // should return an error code only.
        return $ismanip ? DB_OK : $result;
    }

    // }}}
    // {{{ nextResult()

    /**
     * Move the internal sybase result pointer to the next available result
     *
     * @param a valid sybase result resource
     *
     * @access public
     *
     * @return true if a result is available otherwise return false
     */
    function nextResult($result)
    {
        return false;
    }

    // }}}
    // {{{ fetchInto()

    /**
     * Fetch a row and insert the data into an existing array.
     *
     * Formating of the array and the data therein are configurable.
     * See DB_result::fetchInto() for more information.
     *
     * @param resource $result    query result identifier
     * @param array    $arr       (reference) array where data from the row
     *                            should be placed
     * @param int      $fetchmode how the resulting array should be indexed
     * @param int      $rownum    the row number to fetch
     *
     * @return mixed DB_OK on success, null when end of result set is
     *               reached or on failure
     *
     * @see DB_result::fetchInto()
     * @access private
     */
    function fetchInto($result, &$arr, $fetchmode, $rownum=null)
    {
        if ($rownum !== null) {
            if (!@sybase_data_seek($result, $rownum)) {
                return null;
            }
        }
        if ($fetchmode & DB_FETCHMODE_ASSOC) {
            if (function_exists('sybase_fetch_assoc')) {
                $arr = @sybase_fetch_assoc($result);
            } else {
                if ($arr = @sybase_fetch_array($result)) {
                    foreach ($arr as $key => $value) {
                        if (is_int($key)) {
                            unset($arr[$key]);
                        }
                    }
                }
            }
            if ($this->options['portability'] & DB_PORTABILITY_LOWERCASE && $arr) {
                $arr = array_change_key_case($arr, CASE_LOWER);
            }
        } else {
            $arr = @sybase_fetch_row($result);
        }
        if (!$arr) {
            // reported not work as seems that sybase_get_last_message()
            // always return a message here
            //if ($errmsg = @sybase_get_last_message()) {
            //    return $this->sybaseRaiseError($errmsg);
            //} else {
                return null;
            //}
        }
        if ($this->options['portability'] & DB_PORTABILITY_RTRIM) {
            $this->_rtrimArrayValues($arr);
        }
        if ($this->options['portability'] & DB_PORTABILITY_NULL_TO_EMPTY) {
            $this->_convertNullArrayValuesToEmpty($arr);
        }
        return DB_OK;
    }

    // }}}
    // {{{ freeResult()

    /**
     * Free the internal resources associated with $result.
     *
     * @param $result Sybase result identifier
     *
     * @access public
     *
     * @return bool true on success, false if $result is invalid
     */
    function freeResult($result)
    {
        unset($this->num_rows[(int)$result]);
        return @sybase_free_result($result);
    }

    // }}}
    // {{{ numCols()

    /**
     * Get the number of columns in a result set.
     *
     * @param $result Sybase result identifier
     *
     * @access public
     *
     * @return int the number of columns per row in $result
     */
    function numCols($result)
    {
        $cols = @sybase_num_fields($result);
        if (!$cols) {
            return $this->sybaseRaiseError();
        }
        return $cols;
    }

    // }}}
    // {{{ numRows()

    /**
     * Get the number of rows in a result set.
     *
     * @param $result Sybase result identifier
     *
     * @access public
     *
     * @return int the number of rows in $result
     */
    function numRows($result)
    {
        $rows = @sybase_num_rows($result);
        if ($rows === false) {
            return $this->sybaseRaiseError();
        }
        return $rows;
    }

    // }}}
    // {{{ affectedRows()

    /**
     * Gets the number of rows affected by the data manipulation
     * query.  For other queries, this function returns 0.
     *
     * @return number of rows affected by the last query
     */
    function affectedRows()
    {
        if (DB::isManip($this->last_query)) {
            $result = @sybase_affected_rows($this->connection);
        } else {
            $result = 0;
        }
        return $result;
     }

    // }}}
    // {{{ nextId()

    /**
     * Returns the next free id in a sequence
     *
     * @param string  $seq_name  name of the sequence
     * @param boolean $ondemand  when true, the seqence is automatically
     *                           created if it does not exist
     *
     * @return int  the next id number in the sequence.  DB_Error if problem.
     *
     * @internal
     * @see DB_common::nextID()
     * @access public
     */
    function nextId($seq_name, $ondemand = true)
    {
        $seqname = $this->getSequenceName($seq_name);
        if (!@sybase_select_db($this->_db, $this->connection)) {
            return $this->sybaseRaiseError(DB_ERROR_NODBSELECTED);
        }
        $repeat = 0;
        do {
            $this->pushErrorHandling(PEAR_ERROR_RETURN);
            $result = $this->query("INSERT INTO $seqname (vapor) VALUES (0)");
            $this->popErrorHandling();
            if ($ondemand && DB::isError($result) &&
                ($result->getCode() == DB_ERROR || $result->getCode() == DB_ERROR_NOSUCHTABLE))
            {
                $repeat = 1;
                $result = $this->createSequence($seq_name);
                if (DB::isError($result)) {
                    return $this->raiseError($result);
                }
            } elseif (!DB::isError($result)) {
                $result =& $this->query("SELECT @@IDENTITY FROM $seqname");
                $repeat = 0;
            } else {
                $repeat = false;
            }
        } while ($repeat);
        if (DB::isError($result)) {
            return $this->raiseError($result);
        }
        $result = $result->fetchRow(DB_FETCHMODE_ORDERED);
        return $result[0];
    }

    /**
     * Creates a new sequence
     *
     * @param string $seq_name  name of the new sequence
     *
     * @return int  DB_OK on success.  A DB_Error object is returned if
     *              problems arise.
     *
     * @internal
     * @see DB_common::createSequence()
     * @access public
     */
    function createSequence($seq_name)
    {
        $seqname = $this->getSequenceName($seq_name);
        return $this->query("CREATE TABLE $seqname ".
                            '(id numeric(10,0) IDENTITY NOT NULL ,' .
                            'vapor int NULL)');
    }

    // }}}
    // {{{ dropSequence()

    /**
     * Deletes a sequence
     *
     * @param string $seq_name  name of the sequence to be deleted
     *
     * @return int  DB_OK on success.  DB_Error if problems.
     *
     * @internal
     * @see DB_common::dropSequence()
     * @access public
     */
    function dropSequence($seq_name)
    {
        $seqname = $this->getSequenceName($seq_name);
        return $this->query("DROP TABLE $seqname");
    }

    // }}}
    // {{{ getSpecialQuery()

    /**
     * Returns the query needed to get some backend info
     * @param string $type What kind of info you want to retrieve
     * @return string The SQL query string
     */
    function getSpecialQuery($type)
    {
        switch ($type) {
            case 'tables':
                return "select name from sysobjects where type = 'U' order by name";
            case 'views':
                return "select name from sysobjects where type = 'V'";
            default:
                return null;
        }
    }

    // }}}
    // {{{ autoCommit()

    /**
     * Enable/disable automatic commits
     */
    function autoCommit($onoff = false)
    {
        // XXX if $this->transaction_opcount > 0, we should probably
        // issue a warning here.
        $this->autocommit = $onoff ? true : false;
        return DB_OK;
    }

    // }}}
    // {{{ commit()

    /**
     * Commit the current transaction.
     */
    function commit()
    {
        if ($this->transaction_opcount > 0) {
            if (!@sybase_select_db($this->_db, $this->connection)) {
                return $this->sybaseRaiseError(DB_ERROR_NODBSELECTED);
            }
            $result = @sybase_query('COMMIT', $this->connection);
            $this->transaction_opcount = 0;
            if (!$result) {
                return $this->sybaseRaiseError();
            }
        }
        return DB_OK;
    }

    // }}}
    // {{{ rollback()

    /**
     * Roll back (undo) the current transaction.
     */
    function rollback()
    {
        if ($this->transaction_opcount > 0) {
            if (!@sybase_select_db($this->_db, $this->connection)) {
                return $this->sybaseRaiseError(DB_ERROR_NODBSELECTED);
            }
            $result = @sybase_query('ROLLBACK', $this->connection);
            $this->transaction_opcount = 0;
            if (!$result) {
                return $this->sybaseRaiseError();
            }
        }
        return DB_OK;
    }

    // }}}
    // {{{ tableInfo()

    /**
     * Returns information about a table or a result set.
     *
     * NOTE: only supports 'table' and 'flags' if <var>$result</var>
     * is a table name.
     *
     * @param object|string  $result  DB_result object from a query or a
     *                                string containing the name of a table
     * @param int            $mode    a valid tableInfo mode
     * @return array  an associative array with the information requested
     *                or an error object if something is wrong
     * @access public
     * @internal
     * @since 1.6.0
     * @see DB_common::tableInfo()
     */
    function tableInfo($result, $mode = null)
    {
        if (isset($result->result)) {
            /*
             * Probably received a result object.
             * Extract the result resource identifier.
             */
            $id = $result->result;
            $got_string = false;
        } elseif (is_string($result)) {
            /*
             * Probably received a table name.
             * Create a result resource identifier.
             */
            if (!@sybase_select_db($this->_db, $this->connection)) {
                return $this->sybaseRaiseError(DB_ERROR_NODBSELECTED);
            }
            $id = @sybase_query("SELECT * FROM $result WHERE 1=0",
                                $this->connection);
            $got_string = true;
        } else {
            /*
             * Probably received a result resource identifier.
             * Copy it.
             * Depricated.  Here for compatibility only.
             */
            $id = $result;
            $got_string = false;
        }

        if (!is_resource($id)) {
            return $this->sybaseRaiseError(DB_ERROR_NEED_MORE_DATA);
        }

        if ($this->options['portability'] & DB_PORTABILITY_LOWERCASE) {
            $case_func = 'strtolower';
        } else {
            $case_func = 'strval';
        }

        $count = @sybase_num_fields($id);

        // made this IF due to performance (one if is faster than $count if's)
        if (!$mode) {

            for ($i=0; $i<$count; $i++) {
                $f = @sybase_fetch_field($id, $i);

                // column_source is often blank
                if ($got_string) {
                    $res[$i]['table'] = $case_func($result);
                } else {
                    $res[$i]['table'] = $case_func($f->column_source);
                }
                $res[$i]['name']  = $case_func($f->name);
                $res[$i]['type']  = $f->type;
                $res[$i]['len']   = $f->max_length;
                if ($res[$i]['table']) {
                    $res[$i]['flags'] = $this->_sybase_field_flags(
                            $res[$i]['table'], $res[$i]['name']);
                } else {
                    $res[$i]['flags'] = '';
                }
            }

        } else {
            // get full info

            $res['num_fields'] = $count;

            for ($i=0; $i<$count; $i++) {
                $f = @sybase_fetch_field($id, $i);

                // column_source is often blank
                if ($got_string) {
                    $res[$i]['table'] = $case_func($result);
                } else {
                    $res[$i]['table'] = $case_func($f->column_source);
                }
                $res[$i]['name']  = $case_func($f->name);
                $res[$i]['type']  = $f->type;
                $res[$i]['len']   = $f->max_length;
                if ($res[$i]['table']) {
                    $res[$i]['flags'] = $this->_sybase_field_flags(
                            $res[$i]['table'], $res[$i]['name']);
                } else {
                    $res[$i]['flags'] = '';
                }

                if ($mode & DB_TABLEINFO_ORDER) {
                    $res['order'][$res[$i]['name']] = $i;
                }
                if ($mode & DB_TABLEINFO_ORDERTABLE) {
                    $res['ordertable'][$res[$i]['table']][$res[$i]['name']] = $i;
                }
            }
        }

        // free the result only if we were called on a table
        if ($got_string) {
            @sybase_free_result($id);
        }
        return $res;
    }

    // }}}
    // {{{ _sybase_field_flags()

    /**
     * Get the flags for a field.
     *
     * Currently supports:
     *  + <samp>unique_key</samp>    (unique index, unique check or primary_key)
     *  + <samp>multiple_key</samp>  (multi-key index)
     *
     * @param string  $table   table name
     * @param string  $column  field name
     * @return string  space delimited string of flags.  Empty string if none.
     * @access private
     */
    function _sybase_field_flags($table, $column)
    {
        static $tableName = null;
        static $flags = array();

        if ($table != $tableName) {
            $flags = array();
            $tableName = $table;

            // get unique/primary keys
            $res = $this->getAll("sp_helpindex $table", DB_FETCHMODE_ASSOC);

            if (!isset($res[0]['index_description'])) {
                return '';
            }

            foreach ($res as $val) {
                $keys = explode(', ', trim($val['index_keys']));

                if (sizeof($keys) > 1) {
                    foreach ($keys as $key) {
                        $this->_add_flag($flags[$key], 'multiple_key');
                    }
                }

                if (strpos($val['index_description'], 'unique')) {
                    foreach ($keys as $key) {
                        $this->_add_flag($flags[$key], 'unique_key');
                    }
                }
            }

        }

        if (array_key_exists($column, $flags)) {
            return(implode(' ', $flags[$column]));
        }

        return '';
    }

    // }}}
    // {{{ _add_flag()

    /**
     * Adds a string to the flags array if the flag is not yet in there
     * - if there is no flag present the array is created.
     *
     * @param array  $array  reference of flags array to add a value to
     * @param mixed  $value  value to add to the flag array
     * @access private
     */
    function _add_flag(&$array, $value)
    {
        if (!is_array($array)) {
            $array = array($value);
        } elseif (!in_array($value, $array)) {
            array_push($array, $value);
        }
    }

    // }}}
    // {{{ quoteIdentifier()

    /**
     * Quote a string so it can be safely used as a table / column name
     *
     * Quoting style depends on which database driver is being used.
     *
     * @param string $str  identifier name to be quoted
     *
     * @return string  quoted identifier string
     *
     * @since 1.6.0
     * @access public
     */
    function quoteIdentifier($str)
    {
        return '[' . str_replace(']', ']]', $str) . ']';
    }

    // }}}

}

/*
 * Local variables:
 * tab-width: 4
 * c-basic-offset: 4
 * End:
 */

?>