/common/libraries/plugin/pear/MDB2/Driver/mssql.php

<?php

// vim: set et ts=4 sw=4 fdm=marker:
// +----------------------------------------------------------------------+
// | PHP versions 4 and 5                                                 |
// +----------------------------------------------------------------------+
// | Copyright (c) 1998-2008 Manuel Lemos, Tomas V.V.Cox,                 |
// | Stig. S. Bakken, Lukas Smith, Frank M. Kromann                       |
// | All rights reserved.                                                 |
// +----------------------------------------------------------------------+
// | MDB2 is a merge of PEAR DB and Metabases that provides a unified DB  |
// | API as well as database abstraction for PHP applications.            |
// | This LICENSE is in the BSD license style.                            |
// |                                                                      |
// | Redistribution and use in source and binary forms, with or without   |
// | modification, are permitted provided that the following conditions   |
// | are met:                                                             |
// |                                                                      |
// | Redistributions of source code must retain the above copyright       |
// | notice, this list of conditions and the following disclaimer.        |
// |                                                                      |
// | Redistributions in binary form must reproduce the above copyright    |
// | notice, this list of conditions and the following disclaimer in the  |
// | documentation and/or other materials provided with the distribution. |
// |                                                                      |
// | Neither the name of Manuel Lemos, Tomas V.V.Cox, Stig. S. Bakken,    |
// | Lukas Smith nor the names of his contributors may be used to endorse |
// | or promote products derived from this software without specific prior|
// | written permission.                                                  |
// |                                                                      |
// | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS  |
// | "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT    |
// | LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS    |
// | FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE      |
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// | INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
// | BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS|
// |  OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED  |
// | AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT          |
// | LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY|
// | WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE          |
// | POSSIBILITY OF SUCH DAMAGE.                                          |
// +----------------------------------------------------------------------+
// | Author: Frank M. Kromann <frank@kromann.info>                        |
// +----------------------------------------------------------------------+
//
// $Id: mssql.php 137 2009-11-09 13:24:37Z vanpouckesven $
//
// {{{ Class MDB2_Driver_mssql
/**
 * MDB2 MSSQL Server driver
 *
 * @package MDB2
 * @category Database
 * @author  Frank M. Kromann <frank@kromann.info>
 */

class MDB2_Driver_mssql extends MDB2_Driver_Common

{

    // {{{ properties
    



    var $string_quoting = array('start' => "'", 'end' => "'", 'escape' => "'", 'escape_pattern' => false);

    

    var $identifier_quoting = array('start' => '[', 'end' => ']', 'escape' => ']');



    // }}}
    // {{{ constructor
    



    /**
     * Constructor
     */

    function __construct()

    {

        parent :: __construct();

        

        $this->phptype = 'mssql';

        $this->dbsyntax = 'mssql';

        

        $this->supported['sequences'] = 'emulated';

        $this->supported['indexes'] = true;

        $this->supported['affected_rows'] = true;

        $this->supported['transactions'] = true;

        $this->supported['savepoints'] = false;

        $this->supported['summary_functions'] = true;

        $this->supported['order_by_text'] = true;

        $this->supported['current_id'] = 'emulated';

        $this->supported['limit_queries'] = 'emulated';

        $this->supported['LOBs'] = true;

        $this->supported['replace'] = 'emulated';

        $this->supported['sub_selects'] = true;

        $this->supported['triggers'] = true;

        $this->supported['auto_increment'] = true;

        $this->supported['primary_key'] = true;

        $this->supported['result_introspection'] = true;

        $this->supported['prepared_statements'] = 'emulated';

        $this->supported['pattern_escaping'] = true;

        $this->supported['new_link'] = true;

        

        $this->options['DBA_username'] = false;

        $this->options['DBA_password'] = false;

        $this->options['database_device'] = false;

        $this->options['database_size'] = false;

        $this->options['max_identifiers_length'] = 128; // MS Access: 64
    }



    // }}}
    // {{{ errorInfo()
    



    /**
     * This method is used to collect information about an error
     *
     * @param integer $error
     * @return array
     * @access public
     */

    function errorInfo($error = null, $connection = null)

    {

        if (is_null($connection))

        {

            $connection = $this->connection;

        }

        

        $native_code = null;

        if ($connection)

        {

            $result = @mssql_query('select @@ERROR as ErrorCode', $connection);

            if ($result)

            {

                $native_code = @mssql_result($result, 0, 0);

                @mssql_free_result($result);

            }

        }

        $native_msg = @mssql_get_last_message();

        if (is_null($error))

        {

            static $ecode_map;

            if (empty($ecode_map))

            {

                $ecode_map = array(102 => MDB2_ERROR_SYNTAX, 110 => MDB2_ERROR_VALUE_COUNT_ON_ROW, 

                        155 => MDB2_ERROR_NOSUCHFIELD, 156 => MDB2_ERROR_SYNTAX, 170 => MDB2_ERROR_SYNTAX, 

                        207 => MDB2_ERROR_NOSUCHFIELD, 208 => MDB2_ERROR_NOSUCHTABLE, 245 => MDB2_ERROR_INVALID_NUMBER, 

                        319 => MDB2_ERROR_SYNTAX, 321 => MDB2_ERROR_NOSUCHFIELD, 325 => MDB2_ERROR_SYNTAX, 

                        336 => MDB2_ERROR_SYNTAX, 515 => MDB2_ERROR_CONSTRAINT_NOT_NULL, 547 => MDB2_ERROR_CONSTRAINT, 

                        911 => MDB2_ERROR_NOT_FOUND, 1018 => MDB2_ERROR_SYNTAX, 1035 => MDB2_ERROR_SYNTAX, 

                        1801 => MDB2_ERROR_ALREADY_EXISTS, 1913 => MDB2_ERROR_ALREADY_EXISTS, 2209 => MDB2_ERROR_SYNTAX, 

                        2223 => MDB2_ERROR_SYNTAX, 2248 => MDB2_ERROR_SYNTAX, 2256 => MDB2_ERROR_SYNTAX, 

                        2257 => MDB2_ERROR_SYNTAX, 2627 => MDB2_ERROR_CONSTRAINT, 2714 => MDB2_ERROR_ALREADY_EXISTS, 

                        3607 => MDB2_ERROR_DIVZERO, 3701 => MDB2_ERROR_NOSUCHTABLE, 7630 => MDB2_ERROR_SYNTAX, 

                        8134 => MDB2_ERROR_DIVZERO, 9303 => MDB2_ERROR_SYNTAX, 9317 => MDB2_ERROR_SYNTAX, 

                        9318 => MDB2_ERROR_SYNTAX, 9331 => MDB2_ERROR_SYNTAX, 9332 => MDB2_ERROR_SYNTAX, 

                        15253 => MDB2_ERROR_SYNTAX);

            }

            if (isset($ecode_map[$native_code]))

            {

                if ($native_code == 3701 && preg_match('/Cannot drop the index/i', $native_msg))

                {

                    $error = MDB2_ERROR_NOT_FOUND;

                }

                else

                {

                    $error = $ecode_map[$native_code];

                }

            }

        }

        return array($error, $native_code, $native_msg);

    }



    // }}}
    // {{{ function escapePattern($text)
    



    /**
     * Quotes pattern (% and _) characters in a string)
     *
     * @param   string  the input string to quote
     *
     * @return  string  quoted string
     *
     * @access  public
     */

    function escapePattern($text)

    {

        $text = str_replace("[", "[ [ ]", $text);

        foreach ($this->wildcards as $wildcard)

        {

            $text = str_replace($wildcard, '[' . $wildcard . ']', $text);

        }

        return $text;

    }



    // }}}
    // {{{ beginTransaction()
    



    /**
     * Start a transaction or set a savepoint.
     *
     * @param   string  name of a savepoint to set
     * @return  mixed   MDB2_OK on success, a MDB2 error on failure
     *
     * @access  public
     */

    function beginTransaction($savepoint = null)

    {

        $this->debug('Starting transaction/savepoint', __FUNCTION__, array('is_manip' => true, 

                'savepoint' => $savepoint));

        if (! is_null($savepoint))

        {

            if (! $this->in_transaction)

            {

                return $this->raiseError(MDB2_ERROR_INVALID, null, null, 'savepoint cannot be released when changes are auto committed', __FUNCTION__);

            }

            $query = 'SAVE TRANSACTION ' . $savepoint;

            return $this->_doQuery($query, true);

        }

        elseif ($this->in_transaction)

        {

            return MDB2_OK; //nothing to do
        }

        if (! $this->destructor_registered && $this->opened_persistent)

        {

            $this->destructor_registered = true;

            register_shutdown_function('MDB2_closeOpenTransactions');

        }

        $result = & $this->_doQuery('BEGIN TRANSACTION', true);

        if (PEAR :: isError($result))

        {

            return $result;

        }

        $this->in_transaction = true;

        return MDB2_OK;

    }



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



    /**
     * Commit the database changes done during a transaction that is in
     * progress or release a savepoint. This function may only be called when
     * auto-committing is disabled, otherwise it will fail. Therefore, a new
     * transaction is implicitly started after committing the pending changes.
     *
     * @param   string  name of a savepoint to release
     * @return  mixed   MDB2_OK on success, a MDB2 error on failure
     *
     * @access  public
     */

    function commit($savepoint = null)

    {

        $this->debug('Committing transaction/savepoint', __FUNCTION__, array('is_manip' => true, 

                'savepoint' => $savepoint));

        if (! $this->in_transaction)

        {

            return $this->raiseError(MDB2_ERROR_INVALID, null, null, 'commit/release savepoint cannot be done changes are auto committed', __FUNCTION__);

        }

        if (! is_null($savepoint))

        {

            return MDB2_OK;

        }

        

        $result = & $this->_doQuery('COMMIT TRANSACTION', true);

        if (PEAR :: isError($result))

        {

            return $result;

        }

        $this->in_transaction = false;

        return MDB2_OK;

    }



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



    /**
     * Cancel any database changes done during a transaction or since a specific
     * savepoint that is in progress. This function may only be called when
     * auto-committing is disabled, otherwise it will fail. Therefore, a new
     * transaction is implicitly started after canceling the pending changes.
     *
     * @param   string  name of a savepoint to rollback to
     * @return  mixed   MDB2_OK on success, a MDB2 error on failure
     *
     * @access  public
     */

    function rollback($savepoint = null)

    {

        $this->debug('Rolling back transaction/savepoint', __FUNCTION__, array('is_manip' => true, 

                'savepoint' => $savepoint));

        if (! $this->in_transaction)

        {

            return $this->raiseError(MDB2_ERROR_INVALID, null, null, 'rollback cannot be done changes are auto committed', __FUNCTION__);

        }

        if (! is_null($savepoint))

        {

            $query = 'ROLLBACK TRANSACTION ' . $savepoint;

            return $this->_doQuery($query, true);

        }

        

        $result = & $this->_doQuery('ROLLBACK TRANSACTION', true);

        if (PEAR :: isError($result))

        {

            return $result;

        }

        $this->in_transaction = false;

        return MDB2_OK;

    }



    // }}}
    // {{{ _doConnect()
    



    /**
     * do the grunt work of the connect
     *
     * @return connection on success or MDB2 Error Object on failure
     * @access protected
     */

    function _doConnect($username, $password, $persistent = false)

    {

        if (! PEAR :: loadExtension($this->phptype) && ! PEAR :: loadExtension('sybase_ct'))

        {

            return $this->raiseError(MDB2_ERROR_NOT_FOUND, null, null, 'extension ' . $this->phptype . ' is not compiled into PHP', __FUNCTION__);

        }

        

        $params = array($this->dsn['hostspec'] ? $this->dsn['hostspec'] : 'localhost', $username ? $username : null, 

                $password ? $password : null);

        if ($this->dsn['port'])

        {

            $params[0] .= ((substr(PHP_OS, 0, 3) == 'WIN') ? ',' : ':') . $this->dsn['port'];

        }

        if (! $persistent)

        {

            if ($this->_isNewLinkSet())

            {

                $params[] = true;

            }

            else

            {

                $params[] = false;

            }

        }

        

        $connect_function = $persistent ? 'mssql_pconnect' : 'mssql_connect';

        

        $connection = @call_user_func_array($connect_function, $params);

        if ($connection <= 0)

        {

            return $this->raiseError(MDB2_ERROR_CONNECT_FAILED, null, null, 'unable to establish a connection', __FUNCTION__, __FUNCTION__);

        }

        

        @mssql_query('SET ANSI_NULL_DFLT_ON ON', $connection);

        

        /*
        if (!empty($this->dsn['charset'])) {
            $result = $this->setCharset($this->dsn['charset'], $connection);
            if (PEAR::isError($result)) {
                return $result;
            }
        }
        */

        

        if ((bool) ini_get('mssql.datetimeconvert'))

        {

            @ini_set('mssql.datetimeconvert', '0');

        }

        

        if (empty($this->dsn['disable_iso_date']))

        {

            @mssql_query('SET DATEFORMAT ymd', $connection);

        }

        

        return $connection;

    }



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



    /**
     * Connect to the database
     *
     * @return true on success, MDB2 Error Object on failure
     */

    function connect()

    {

        if (is_resource($this->connection))

        {

            //if (count(array_diff($this->connected_dsn, $this->dsn)) == 0
            if (MDB2 :: areEquals($this->connected_dsn, $this->dsn) && $this->opened_persistent == $this->options['persistent'])

            {

                return MDB2_OK;

            }

            $this->disconnect(false);

        }

        

        $connection = $this->_doConnect($this->dsn['username'], $this->dsn['password'], $this->options['persistent']);

        if (PEAR :: isError($connection))

        {

            return $connection;

        }

        

        $this->connection = $connection;

        $this->connected_dsn = $this->dsn;

        $this->connected_database_name = '';

        $this->opened_persistent = $this->options['persistent'];

        $this->dbsyntax = $this->dsn['dbsyntax'] ? $this->dsn['dbsyntax'] : $this->phptype;

        

        if ($this->database_name)

        {

            if ($this->database_name != $this->connected_database_name)

            {

                if (! @mssql_select_db($this->database_name, $connection))

                {

                    $err = $this->raiseError(null, null, null, 'Could not select the database: ' . $this->database_name, __FUNCTION__);

                    return $err;

                }

                $this->connected_database_name = $this->database_name;

            }

        }

        

        return MDB2_OK;

    }



    // }}}
    // {{{ databaseExists()
    



    /**
     * check if given database name is exists?
     *
     * @param string $name    name of the database that should be checked
     *
     * @return mixed true/false on success, a MDB2 error on failure
     * @access public
     */

    function databaseExists($name)

    {

        $connection = $this->_doConnect($this->dsn['username'], $this->dsn['password'], $this->options['persistent']);

        if (PEAR :: isError($connection))

        {

            return $connection;

        }

        

        $result = @mssql_select_db($name, $connection);

        $errorInfo = $this->errorInfo(null, $connection);

        @mssql_close($connection);

        if (! $result)

        {

            if ($errorInfo[0] != MDB2_ERROR_NOT_FOUND)

            {

                exit();

                $result = $this->raiseError($errorInfo[0], null, null, $errorInfo[2], __FUNCTION__);

                return $result;

            }

            $result = false;

        }

        

        return $result;

    }



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



    /**
     * Log out and disconnect from the database.
     *
     * @param  boolean $force if the disconnect should be forced even if the
     * connection is opened persistently
     * @return mixed true on success, false if not connected and error
     * object on error
     * @access public
     */

    function disconnect($force = true)

    {

        if (is_resource($this->connection))

        {

            if ($this->in_transaction)

            {

                $dsn = $this->dsn;

                $database_name = $this->database_name;

                $persistent = $this->options['persistent'];

                $this->dsn = $this->connected_dsn;

                $this->database_name = $this->connected_database_name;

                $this->options['persistent'] = $this->opened_persistent;

                $this->rollback();

                $this->dsn = $dsn;

                $this->database_name = $database_name;

                $this->options['persistent'] = $persistent;

            }

            

            if (! $this->opened_persistent || $force)

            {

                $ok = @mssql_close($this->connection);

                if (! $ok)

                {

                    return $this->raiseError(MDB2_ERROR_DISCONNECT_FAILED, null, null, null, __FUNCTION__);

                }

            }

        }

        else

        {

            return false;

        }

        return parent :: disconnect($force);

    }



    // }}}
    // {{{ standaloneQuery()
    



    /**
     * execute a query as DBA
     *
     * @param string $query the SQL query
     * @param mixed   $types  array that contains the types of the columns in
     * the result set
     * @param boolean $is_manip  if the query is a manipulation query
     * @return mixed MDB2_OK on success, a MDB2 error on failure
     * @access public
     */

    function &standaloneQuery($query, $types = null, $is_manip = false)

    {

        $user = $this->options['DBA_username'] ? $this->options['DBA_username'] : $this->dsn['username'];

        $pass = $this->options['DBA_password'] ? $this->options['DBA_password'] : $this->dsn['password'];

        $connection = $this->_doConnect($user, $pass, $this->options['persistent']);

        if (PEAR :: isError($connection))

        {

            return $connection;

        }

        

        $offset = $this->offset;

        $limit = $this->limit;

        $this->offset = $this->limit = 0;

        $query = $this->_modifyQuery($query, $is_manip, $limit, $offset);

        

        $result = & $this->_doQuery($query, $is_manip, $connection, $this->database_name);

        if (! PEAR :: isError($result))

        {

            $result = $this->_affectedRows($connection, $result);

        }

        

        @mssql_close($connection);

        return $result;

    }



    // }}}
    // {{{ _doQuery()
    



    /**
     * Execute a query
     * @param string $query  query
     * @param boolean $is_manip  if the query is a manipulation query
     * @param resource $connection
     * @param string $database_name
     * @return result or error object
     * @access protected
     */

    function &_doQuery($query, $is_manip = false, $connection = null, $database_name = null)

    {

        $this->last_query = $query;

        $result = $this->debug($query, 'query', array('is_manip' => $is_manip, 'when' => 'pre'));

        if ($result)

        {

            if (PEAR :: isError($result))

            {

                return $result;

            }

            $query = $result;

        }

        if ($this->options['disable_query'])

        {

            $result = $is_manip ? 0 : null;

            return $result;

        }

        

        if (is_null($connection))

        {

            $connection = $this->getConnection();

            if (PEAR :: isError($connection))

            {

                return $connection;

            }

        }

        if (is_null($database_name))

        {

            $database_name = $this->database_name;

        }

        

        if ($database_name)

        {

            if ($database_name != $this->connected_database_name)

            {

                if (! @mssql_select_db($database_name, $connection))

                {

                    $err = $this->raiseError(null, null, null, 'Could not select the database: ' . $database_name, __FUNCTION__);

                    return $err;

                }

                $this->connected_database_name = $database_name;

            }

        }

        

        $result = @mssql_query($query, $connection);

        if (! $result)

        {

            $err = & $this->raiseError(null, null, null, 'Could not execute statement', __FUNCTION__);

            return $err;

        }

        

        $this->debug($query, 'query', array('is_manip' => $is_manip, 'when' => 'post', 'result' => $result));

        return $result;

    }



    // }}}
    // {{{ _affectedRows()
    



    /**
     * Returns the number of rows affected
     *
     * @param resource $result
     * @param resource $connection
     * @return mixed MDB2 Error Object or the number of rows affected
     * @access private
     */

    function _affectedRows($connection, $result = null)

    {

        if (is_null($connection))

        {

            $connection = $this->getConnection();

            if (PEAR :: isError($connection))

            {

                return $connection;

            }

        }

        return @mssql_rows_affected($connection);

    }



    // }}}
    // {{{ _modifyQuery()
    



    /**
     * Changes a query string for various DBMS specific reasons
     *
     * @param string $query  query to modify
     * @param boolean $is_manip  if it is a DML query
     * @param integer $limit  limit the number of rows
     * @param integer $offset  start reading from given offset
     * @return string modified query
     * @access protected
     */

    function _modifyQuery($query, $is_manip, $limit, $offset)

    {

        if ($limit > 0)

        {

            $fetch = $offset + $limit;

            if (! $is_manip)

            {

                return preg_replace('/^([\s(])*SELECT( DISTINCT)?(?!\s*TOP\s*\()/i', "\\1SELECT\\2 TOP $fetch", $query);

            }

        }

        return $query;

    }



    // }}}
    // {{{ getServerVersion()
    



    /**
     * return version information about the server
     *
     * @param bool   $native  determines if the raw version string should be returned
     * @return mixed array/string with version information or MDB2 error object
     * @access public
     */

    function getServerVersion($native = false)

    {

        if ($this->connected_server_info)

        {

            $server_info = $this->connected_server_info;

        }

        else

        {

            $query = 'SELECT @@VERSION';

            $server_info = $this->queryOne($query, 'text');

            if (PEAR :: isError($server_info))

            {

                return $server_info;

            }

        }

        // cache server_info
        $this->connected_server_info = $server_info;

        if (! $native && ! PEAR :: isError($server_info))

        {

            if (preg_match('/(\d+)\.(\d+)\.(\d+)/', $server_info, $tmp))

            {

                $server_info = array('major' => $tmp[1], 'minor' => $tmp[2], 'patch' => $tmp[3], 'extra' => null, 

                        'native' => $server_info);

            }

            else

            {

                $server_info = array('major' => null, 'minor' => null, 'patch' => null, 'extra' => null, 

                        'native' => $server_info);

            }

        }

        return $server_info;

    }



    // }}}
    // {{{ _checkSequence
    



    /**
     * Checks if there's a sequence that exists.
     *
     * @param  string $seq_name    The sequence name to verify.
     * @return bool   $tableExists The value if the table exists or not
     * @access private
     */

    function _checkSequence($seq_name)

    {

        $query = "SELECT * FROM $seq_name";

        $tableExists = & $this->_doQuery($query, true);

        if (PEAR :: isError($tableExists))

        {

            if ($tableExists->getCode() == MDB2_ERROR_NOSUCHTABLE)

            {

                return false;

            }

            //return $tableExists;
            return false;

        }

        return mssql_result($tableExists, 0, 0);

    }



    // }}}
    // {{{ nextID()
    



    /**
     * Returns the next free id of a sequence
     *
     * @param string $seq_name name of the sequence
     * @param boolean $ondemand when true the sequence is
     * automatic created, if it
     * not exists
     *
     * @return mixed MDB2 Error Object or id
     * @access public
     */

    function nextID($seq_name, $ondemand = true)

    {

        $sequence_name = $this->quoteIdentifier($this->getSequenceName($seq_name), true);

        $seqcol_name = $this->quoteIdentifier($this->options['seqcol_name'], true);

        $this->pushErrorHandling(PEAR_ERROR_RETURN);

        $this->expectError(MDB2_ERROR_NOSUCHTABLE);

        

        $seq_val = $this->_checkSequence($sequence_name);

        

        if ($seq_val)

        {

            $query = "SET IDENTITY_INSERT $sequence_name OFF " . "INSERT INTO $sequence_name DEFAULT VALUES";

        }

        else

        {

            $query = "INSERT INTO $sequence_name ($seqcol_name) VALUES (0)";

        }

        $result = & $this->_doQuery($query, true);

        $this->popExpect();

        $this->popErrorHandling();

        if (PEAR :: isError($result))

        {

            if ($ondemand && ! $this->_checkSequence($sequence_name))

            {

                $this->loadModule('Manager', null, true);

                $result = $this->manager->createSequence($seq_name);

                if (PEAR :: isError($result))

                {

                    return $this->raiseError($result, null, null, 'on demand sequence ' . $seq_name . ' could not be created', __FUNCTION__);

                }

                else

                {

                    /**
                     * Little off-by-one problem with the sequence emulation
                     * here being fixed, that instead of re-calling nextID
                     * and forcing an increment by one, we simply check if it
                     * exists, then we get the last inserted id if it does.
                     *
                     * In theory, $seq_name should be created otherwise there would
                     * have been an error thrown somewhere up there.. 
                     *
                     * @todo confirm
                     */

                    if ($this->_checkSequence($seq_name))

                    {

                        return $this->lastInsertID($seq_name);

                    }

                    

                    return $this->nextID($seq_name, false);

                }

            }

            return $result;

        }

        $value = $this->lastInsertID($sequence_name);

        if (is_numeric($value))

        {

            $query = "DELETE FROM $sequence_name WHERE $seqcol_name < $value";

            $result = & $this->_doQuery($query, true);

            if (PEAR :: isError($result))

            {

                $this->warnings[] = 'nextID: could not delete previous sequence table values from ' . $seq_name;

            }

        }

        return $value;

    }



    // }}}
    // {{{ lastInsertID()
    



    /**
     * Returns the autoincrement ID if supported or $id or fetches the current
     * ID in a sequence called: $table.(empty($field) ? '' : '_'.$field)
     *
     * @param string $table name of the table into which a new row was inserted
     * @param string $field name of the field into which a new row was inserted
     *
     * @return mixed MDB2 Error Object or id
     * @access public
     */

    function lastInsertID($table = null, $field = null)

    {

        $server_info = $this->getServerVersion();

        if (is_array($server_info) && ! is_null($server_info['major']) && $server_info['major'] >= 8)

        {

            $query = "SELECT IDENT_CURRENT('$table')";

        }

        else

        {

            $query = "SELECT @@IDENTITY";

            if (! is_null($table))

            {

                $query .= ' FROM ' . $this->quoteIdentifier($table, true);

            }

        }

        

        return $this->queryOne($query, 'integer');

    }



    // }}}
}



// }}}
// {{{ Class MDB2_Result_mssql




/**
 * MDB2 MSSQL Server result driver
 *
 * @package MDB2
 * @category Database
 * @author  Frank M. Kromann <frank@kromann.info>
 */

class MDB2_Result_mssql extends MDB2_Result_Common

{



    // {{{ _skipLimitOffset()
    



    /**
     * Skip the first row of a result set.
     *
     * @param resource $result
     * @return mixed a result handle or MDB2_OK on success, a MDB2 error on failure
     * @access protected
     */

    function _skipLimitOffset()

    {

        if ($this->limit)

        {

            if ($this->rownum >= $this->limit)

            {

                return false;

            }

        }

        if ($this->offset)

        {

            while ($this->offset_count < $this->offset)

            {

                ++ $this->offset_count;

                if (! is_array(@mssql_fetch_row($this->result)))

                {

                    $this->offset_count = $this->limit;

                    return false;

                }

            }

        }

        return MDB2_OK;

    }



    // }}}
    // {{{ fetchRow()
    



    /**
     * Fetch a row and insert the data into an existing array.
     *
     * @param int       $fetchmode  how the array data should be indexed
     * @param int    $rownum    number of the row where the data can be found
     * @return int data array on success, a MDB2 error on failure
     * @access public
     */

    function &fetchRow($fetchmode = MDB2_FETCHMODE_DEFAULT, $rownum = null)

    {

        if (! $this->_skipLimitOffset())

        {

            $null = null;

            return $null;

        }

        if (! is_null($rownum))

        {

            $seek = $this->seek($rownum);

            if (PEAR :: isError($seek))

            {

                return $seek;

            }

        }

        if ($fetchmode == MDB2_FETCHMODE_DEFAULT)

        {

            $fetchmode = $this->db->fetchmode;

        }

        if ($fetchmode & MDB2_FETCHMODE_ASSOC)

        {

            $row = @mssql_fetch_assoc($this->result);

            if (is_array($row) && $this->db->options['portability'] & MDB2_PORTABILITY_FIX_CASE)

            {

                $row = array_change_key_case($row, $this->db->options['field_case']);

            }

        }

        else

        {

            $row = @mssql_fetch_row($this->result);

        }

        if (! $row)

        {

            if ($this->result === false)

            {

                $err = & $this->db->raiseError(MDB2_ERROR_NEED_MORE_DATA, null, null, 'resultset has already been freed', __FUNCTION__);

                return $err;

            }

            $null = null;

            return $null;

        }

        $mode = $this->db->options['portability'] & MDB2_PORTABILITY_EMPTY_TO_NULL;

        $rtrim = false;

        if ($this->db->options['portability'] & MDB2_PORTABILITY_RTRIM)

        {

            if (empty($this->types))

            {

                $mode += MDB2_PORTABILITY_RTRIM;

            }

            else

            {

                $rtrim = true;

            }

        }

        if ($mode)

        {

            $this->db->_fixResultArrayValues($row, $mode);

        }

        if (! ($fetchmode & MDB2_FETCHMODE_ASSOC) && ! empty($this->types))

        {

            $row = $this->db->datatype->convertResultRow($this->types, $row, $rtrim);

        }

        elseif (($fetchmode & MDB2_FETCHMODE_ASSOC) && ! empty($this->types_assoc))

        {

            $row = $this->db->datatype->convertResultRow($this->types_assoc, $row, $rtrim);

        }

        if (! empty($this->values))

        {

            $this->_assignBindColumns($row);

        }

        if ($fetchmode === MDB2_FETCHMODE_OBJECT)

        {

            $object_class = $this->db->options['fetch_class'];

            if ($object_class == 'stdClass')

            {

                $row = (object) $row;

            }

            else

            {

                $row = &new $object_class($row);

            }

        }

        ++ $this->rownum;

        return $row;

    }



    // }}}
    // {{{ _getColumnNames()
    



    /**
     * Retrieve the names of columns returned by the DBMS in a query result.
     *
     * @return  mixed   Array variable that holds the names of columns as keys
     * or an MDB2 error on failure.
     * Some DBMS may not return any columns when the result set
     * does not contain any rows.
     * @access private
     */

    function _getColumnNames()

    {

        $columns = array();

        $numcols = $this->numCols();

        if (PEAR :: isError($numcols))

        {

            return $numcols;

        }

        for($column = 0; $column < $numcols; $column ++)

        {

            $column_name = @mssql_field_name($this->result, $column);

            $columns[$column_name] = $column;

        }

        if ($this->db->options['portability'] & MDB2_PORTABILITY_FIX_CASE)

        {

            $columns = array_change_key_case($columns, $this->db->options['field_case']);

        }

        return $columns;

    }



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



    /**
     * Count the number of columns returned by the DBMS in a query result.
     *
     * @return mixed integer value with the number of columns, a MDB2 error
     * on failure
     * @access public
     */

    function numCols()

    {

        $cols = @mssql_num_fields($this->result);

        if (is_null($cols))

        {

            if ($this->result === false)

            {

                return $this->db->raiseError(MDB2_ERROR_NEED_MORE_DATA, null, null, 'resultset has already been freed', __FUNCTION__);

            }

            elseif (is_null($this->result))

            {

                return count($this->types);

            }

            return $this->db->raiseError(null, null, null, 'Could not get column count', __FUNCTION__);

        }

        return $cols;

    }



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



    /**
     * Move the internal result pointer to the next available result
     *
     * @return true on success, false if there is no more result set or an error object on failure
     * @access public
     */

    function nextResult()

    {

        if ($this->result === false)

        {

            return $this->db->raiseError(MDB2_ERROR_NEED_MORE_DATA, null, null, 'resultset has already been freed', __FUNCTION__);

        }

        elseif (is_null($this->result))

        {

            return false;

        }

        return @mssql_next_result($this->result);

    }



    // }}}
    // {{{ free()
    



    /**
     * Free the internal resources associated with $result.
     *
     * @return boolean true on success, false if $result is invalid
     * @access public
     */

    function free()

    {

        if (is_resource($this->result) && $this->db->connection)

        {

            $free = @mssql_free_result($this->result);

            if ($free === false)

            {

                return $this->db->raiseError(null, null, null, 'Could not free result', __FUNCTION__);

            }

        }

        $this->result = false;

        return MDB2_OK;

    }



    // }}}
}



// }}}
// {{{ class MDB2_BufferedResult_mssql




/**
 * MDB2 MSSQL Server buffered result driver
 *
 * @package MDB2
 * @category Database
 * @author  Frank M. Kromann <frank@kromann.info>
 */

class MDB2_BufferedResult_mssql extends MDB2_Result_mssql

{



    // {{{ seek()
    



    /**
     * Seek to a specific row in a result set
     *
     * @param int    $rownum    number of the row where the data can be found
     * @return mixed MDB2_OK on success, a MDB2 error on failure
     * @access public
     */

    function seek($rownum = 0)

    {

        if ($this->rownum != ($rownum - 1) && ! @mssql_data_seek($this->result, $rownum))

        {

            if ($this->result === false)

            {

                return $this->db->raiseError(MDB2_ERROR_NEED_MORE_DATA, null, null, 'resultset has already been freed', __FUNCTION__);

            }

            elseif (is_null($this->result))

            {

                return MDB2_OK;

            }

            return $this->db->raiseError(MDB2_ERROR_INVALID, null, null, 'tried to seek to an invalid row number (' . $rownum . ')', __FUNCTION__);

        }

        $this->rownum = $rownum - 1;

        return MDB2_OK;

    }



    // }}}
    // {{{ valid()
    



    /**
     * Check if the end of the result set has been reached
     *
     * @return mixed true or false on sucess, a MDB2 error on failure
     * @access public
     */

    function valid()

    {

        $numrows = $this->numRows();

        if (PEAR :: isError($numrows))

        {

            return $numrows;

        }

        return $this->rownum < ($numrows - 1);

    }



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



    /**
     * Returns the number of rows in a result object
     *
     * @return mixed MDB2 Error Object or the number of rows
     * @access public
     */

    function numRows()

    {

        $rows = @mssql_num_rows($this->result);

        if (is_null($rows))

        {

            if ($this->result === false)

            {

                return $this->db->raiseError(MDB2_ERROR_NEED_MORE_DATA, null, null, 'resultset has already been freed', __FUNCTION__);

            }

            elseif (is_null($this->result))

            {

                return 0;

            }

            return $this->db->raiseError(null, null, null, 'Could not get row count', __FUNCTION__);

        }

        if ($this->limit)

        {

            $rows -= $this->offset;

            if ($rows > $this->limit)

            {

                $rows = $this->limit;

            }

            if ($rows < 0)

            {

                $rows = 0;

            }

        }

        return $rows;

    }

}



// }}}
// {{{ MDB2_Statement_mssql




/**
 * MDB2 MSSQL Server statement driver
 *
 * @package MDB2
 * @category Database
 * @author  Frank M. Kromann <frank@kromann.info>
 */

class MDB2_Statement_mssql extends MDB2_Statement_Common

{



}



// }}}
?>