mssql.php

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     *
     * @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 || $force) {
                @mssql_close($this->connection);
            }
        }
        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.. 
                     *