MDB2.php

    // {{{ function beginTransaction($savepoint = null)

    /**
     * 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', __FUNCTION__, array('is_manip' => true, 'savepoint' => $savepoint));
        return $this->raiseError(MDB2_ERROR_UNSUPPORTED, null, null,
            'transactions are not supported', __FUNCTION__);
    }

    // }}}
    // {{{ function commit($savepoint = null)

    /**
     * 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));
        return $this->raiseError(MDB2_ERROR_UNSUPPORTED, null, null,
            'commiting transactions is not supported', __FUNCTION__);
    }

    // }}}
    // {{{ function rollback($savepoint = null)

    /**
     * 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));
        return $this->raiseError(MDB2_ERROR_UNSUPPORTED, null, null,
            'rolling back transactions is not supported', __FUNCTION__);
    }

    // }}}
    // {{{ function inTransaction($ignore_nested = false)

    /**
     * If a transaction is currently open.
     *
     * @param   bool    if the nested transaction count should be ignored
     * @return  int|bool    - an integer with the nesting depth is returned if a
     *                      nested transaction is open
     *                      - true is returned for a normal open transaction
     *                      - false is returned if no transaction is open
     *
     * @access  public
     */
    function inTransaction($ignore_nested = false)
    {
        if (!$ignore_nested && isset($this->nested_transaction_counter)) {
            return $this->nested_transaction_counter;
        }
        return $this->in_transaction;
    }

    // }}}
    // {{{ function setTransactionIsolation($isolation)

    /**
     * Set the transacton isolation level.
     *
     * @param   string  standard isolation level
     *                  READ UNCOMMITTED (allows dirty reads)
     *                  READ COMMITTED (prevents dirty reads)
     *                  REPEATABLE READ (prevents nonrepeatable reads)
     *                  SERIALIZABLE (prevents phantom reads)
     * @param   array some transaction options:
     *                  'wait' => 'WAIT' | 'NO WAIT'
     *                  'rw'   => 'READ WRITE' | 'READ ONLY'
     * @return  mixed   MDB2_OK on success, a MDB2 error on failure
     *
     * @access  public
     * @since   2.1.1
     */
    static function setTransactionIsolation($isolation, $options = array())
    {
        $this->debug('Setting transaction isolation level', __FUNCTION__, array('is_manip' => true));
        return $this->raiseError(MDB2_ERROR_UNSUPPORTED, null, null,
            'isolation level setting is not supported', __FUNCTION__);
    }

    // }}}
    // {{{ function beginNestedTransaction($savepoint = false)

    /**
     * Start a nested transaction.
     *
     * @return  mixed   MDB2_OK on success/savepoint name, a MDB2 error on failure
     *
     * @access  public
     * @since   2.1.1
     */
    function beginNestedTransaction()
    {
        if ($this->in_transaction) {
            ++$this->nested_transaction_counter;
            $savepoint = sprintf($this->options['savepoint_format'], $this->nested_transaction_counter);
            if ($this->supports('savepoints') && $savepoint) {
                return $this->beginTransaction($savepoint);
            }
            return MDB2_OK;
        }
        $this->has_transaction_error = false;
        $result = $this->beginTransaction();
        $this->nested_transaction_counter = 1;
        return $result;
    }

    // }}}
    // {{{ function completeNestedTransaction($force_rollback = false, $release = false)

    /**
     * Finish a nested transaction by rolling back if an error occured or
     * committing otherwise.
     *
     * @param   bool    if the transaction should be rolled back regardless
     *                  even if no error was set within the nested transaction
     * @return  mixed   MDB_OK on commit/counter decrementing, false on rollback
     *                  and a MDB2 error on failure
     *
     * @access  public
     * @since   2.1.1
     */
    function completeNestedTransaction($force_rollback = false)
    {
        if ($this->nested_transaction_counter > 1) {
            $savepoint = sprintf($this->options['savepoint_format'], $this->nested_transaction_counter);
            if ($this->supports('savepoints') && $savepoint) {
                if ($force_rollback || $this->has_transaction_error) {
                    $result = $this->rollback($savepoint);
                    if (!PEAR::isError($result)) {
                        $result = false;
                        $this->has_transaction_error = false;
                    }
                } else {
                    $result = $this->commit($savepoint);
                }
            } else {
                $result = MDB2_OK;
            }
            --$this->nested_transaction_counter;
            return $result;
        }

        $this->nested_transaction_counter = null;
        $result = MDB2_OK;

        // transaction has not yet been rolled back
        if ($this->in_transaction) {
            if ($force_rollback || $this->has_transaction_error) {
                $result = $this->rollback();
                if (!PEAR::isError($result)) {
                    $result = false;
                }
            } else {
                $result = $this->commit();
            }
        }
        $this->has_transaction_error = false;
        return $result;
    }

    // }}}
    // {{{ function failNestedTransaction($error = null, $immediately = false)

    /**
     * Force setting nested transaction to failed.
     *
     * @param   mixed   value to return in getNestededTransactionError()
     * @param   bool    if the transaction should be rolled back immediately
     * @return  bool    MDB2_OK
     *
     * @access  public
     * @since   2.1.1
     */
    function failNestedTransaction($error = null, $immediately = false)
    {
        if (is_null($error)) {
            $error = $this->has_transaction_error ? $this->has_transaction_error : true;
        } elseif (!$error) {
            $error = true;
        }
        $this->has_transaction_error = $error;
        if (!$immediately) {
            return MDB2_OK;
        }
        return $this->rollback();
    }

    // }}}
    // {{{ function getNestedTransactionError()

    /**
     * The first error that occured since the transaction start.
     *
     * @return  MDB2_Error|bool     MDB2 error object if an error occured or false.
     *
     * @access  public
     * @since   2.1.1
     */
    function getNestedTransactionError()
    {
        return $this->has_transaction_error;
    }

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

    /**
     * Connect to the database
     *
     * @return true on success, MDB2 Error Object on failure
     */
    function connect()
    {
        return $this->raiseError(MDB2_ERROR_UNSUPPORTED, null, null,
            'method not implemented', __FUNCTION__);
    }

    // }}}
    // {{{ 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)
    {
        return $this->raiseError(MDB2_ERROR_UNSUPPORTED, null, null,
            'method not implemented', __FUNCTION__);
    }

    // }}}
    // {{{ setCharset($charset, $connection = null)

    /**
     * Set the charset on the current connection
     *
     * @param string    charset
     * @param resource  connection handle
     *
     * @return true on success, MDB2 Error Object on failure
     */
    function setCharset($charset, $connection = null)
    {
        return $this->raiseError(MDB2_ERROR_UNSUPPORTED, null, null,
            'method not implemented', __FUNCTION__);
    }

    // }}}
    // {{{ function disconnect($force = true)

    /**
     * Log out and disconnect from the database.
     *
     * @param boolean $force whether the disconnect should be forced even if the
     *                       connection is opened persistently
     *
     * @return mixed true on success, false if not connected and error object on error
     *
     * @access  public
     */
    function disconnect($force = true)
    {
        $this->connection = 0;
        $this->connected_dsn = array();
        $this->connected_database_name = '';
        $this->opened_persistent = null;
        $this->connected_server_info = '';
        $this->in_transaction = null;
        $this->nested_transaction_counter = null;
        return MDB2_OK;
    }

    // }}}
    // {{{ function setDatabase($name)

    /**
     * Select a different database
     *
     * @param   string  name of the database that should be selected
     *
     * @return  string  name of the database previously connected to
     *
     * @access  public
     */
    function setDatabase($name)
    {
        $previous_database_name = (isset($this->database_name)) ? $this->database_name : '';
        $this->database_name = $name;
        if (!empty($this->connected_database_name) && ($this->connected_database_name != $this->database_name)) {
            $this->disconnect(false);
        }
        return $previous_database_name;
    }

    // }}}
    // {{{ function getDatabase()

    /**
     * Get the current database
     *
     * @return  string  name of the database
     *
     * @access  public
     */
    function getDatabase()
    {
        return $this->database_name;
    }

    // }}}
    // {{{ function setDSN($dsn)

    /**
     * set the DSN
     *
     * @param   mixed   DSN string or array
     *
     * @return  MDB2_OK
     *
     * @access  public
     */
    function setDSN($dsn)
    {
        $dsn_default = $GLOBALS['_MDB2_dsninfo_default'];
        $dsn = MDB2::parseDSN($dsn);
        if (array_key_exists('database', $dsn)) {
            $this->database_name = $dsn['database'];
            unset($dsn['database']);
        }
        $this->dsn = array_merge($dsn_default, $dsn);
        return $this->disconnect(false);
    }

    // }}}
    // {{{ function getDSN($type = 'string', $hidepw = false)

    /**
     * return the DSN as a string
     *
     * @param   string  format to return ("array", "string")
     * @param   string  string to hide the password with
     *
     * @return  mixed   DSN in the chosen type
     *
     * @access  public
     */
    function getDSN($type = 'string', $hidepw = false)
    {
        $dsn = array_merge($GLOBALS['_MDB2_dsninfo_default'], $this->dsn);
        $dsn['phptype'] = $this->phptype;
        $dsn['database'] = $this->database_name;
        if ($hidepw) {
            $dsn['password'] = $hidepw;
        }
        switch ($type) {
        // expand to include all possible options
        case 'string':
           $dsn = $dsn['phptype'].
               ($dsn['dbsyntax'] ? ('('.$dsn['dbsyntax'].')') : '').
               '://'.$dsn['username'].':'.
                $dsn['password'].'@'.$dsn['hostspec'].
                ($dsn['port'] ? (':'.$dsn['port']) : '').
                '/'.$dsn['database'];
            break;
        case 'array':
        default:
            break;
        }
        return $dsn;
    }

    // }}}
    // {{{ _isNewLinkSet()

    /**
     * Check if the 'new_link' option is set
     *
     * @return boolean
     *
     * @access protected
     */
    function _isNewLinkSet()
    {
        return (isset($this->dsn['new_link'])
            && ($this->dsn['new_link'] === true
             || (is_string($this->dsn['new_link']) && preg_match('/^true$/i', $this->dsn['new_link']))
             || (is_numeric($this->dsn['new_link']) && 0 != (int)$this->dsn['new_link'])
            )
        );
    }

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

   /**
     * execute a query as database administrator
     *
     * @param   string  the SQL query
     * @param   mixed   array that contains the types of the columns in
     *                        the result set
     * @param   bool    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)
    {
        $offset = $this->offset;
        $limit = $this->limit;
        $this->offset = $this->limit = 0;
        $query = $this->_modifyQuery($query, $is_manip, $limit, $offset);

        $connection = $this->getConnection();
        if (PEAR::isError($connection)) {
            return $connection;
        }

        $result =$this->_doQuery($query, $is_manip, $connection, false);
        if (PEAR::isError($result)) {
            return $result;
        }

        if ($is_manip) {
            $affected_rows =  $this->_affectedRows($connection, $result);
            return $affected_rows;
        }
        $result =$this->_wrapResult($result, $types, true, false, $limit, $offset);
        return $result;
    }

    // }}}
    // {{{ function _modifyQuery($query, $is_manip, $limit, $offset)

    /**
     * Changes a query string for various DBMS specific reasons
     *
     * @param   string  query to modify
     * @param   bool    if it is a DML query
     * @param   int  limit the number of rows
     * @param   int  start reading from given offset
     *
     * @return  string  modified query
     *
     * @access  protected
     */
    function _modifyQuery($query, $is_manip, $limit, $offset)
    {
        return $query;
    }

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

    /**
     * Execute a query
     * @param   string  query
     * @param   bool    if the query is a manipulation query
     * @param   resource connection handle
     * @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;
        }
        $err =$this->raiseError(MDB2_ERROR_UNSUPPORTED, null, null,
            'method not implemented', __FUNCTION__);
        return $err;
    }

    // }}}
    // {{{ function _affectedRows($connection, $result = null)

    /**
     * Returns the number of rows affected
     *
     * @param   resource result handle
     * @param   resource connection handle
     *
     * @return  mixed   MDB2 Error Object or the number of rows affected
     *
     * @access  private
     */
    function _affectedRows($connection, $result = null)
    {
        return $this->raiseError(MDB2_ERROR_UNSUPPORTED, null, null,
            'method not implemented', __FUNCTION__);
    }

    // }}}
    // {{{ function &exec($query)

    /**
     * Execute a manipulation query to the database and return the number of affected rows
     *
     * @param   string  the SQL query
     *
     * @return  mixed   number of affected rows on success, a MDB2 error on failure
     *
     * @access  public
     */
    function &exec($query)
    {
        $offset = $this->offset;
        $limit = $this->limit;
        $this->offset = $this->limit = 0;
        $query = $this->_modifyQuery($query, true, $limit, $offset);

        $connection = $this->getConnection();
        if (PEAR::isError($connection)) {
            return $connection;
        }

        $result =$this->_doQuery($query, true, $connection, $this->database_name);
        if (PEAR::isError($result)) {
            return $result;
        }

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

    // }}}
    // {{{ function &query($query, $types = null, $result_class = true, $result_wrap_class = false)

    /**
     * Send a query to the database and return any results
     *
     * @param   string  the SQL query
     * @param   mixed   array that contains the types of the columns in
     *                        the result set
     * @param   mixed   string which specifies which result class to use
     * @param   mixed   string which specifies which class to wrap results in
     *
     * @return mixed   an MDB2_Result handle on success, a MDB2 error on failure
     *
     * @access  public
     */
    function &query($query, $types = null, $result_class = true, $result_wrap_class = false)
    {
        $offset = $this->offset;
        $limit = $this->limit;
        $this->offset = $this->limit = 0;
        $query = $this->_modifyQuery($query, false, $limit, $offset);

        $connection = $this->getConnection();
        if (PEAR::isError($connection)) {
            return $connection;
        }

        $result =$this->_doQuery($query, false, $connection, $this->database_name);
        if (PEAR::isError($result)) {
            return $result;
        }

        $result =$this->_wrapResult($result, $types, $result_class, $result_wrap_class, $limit, $offset);
        return $result;
    }

    // }}}
    // {{{ function &_wrapResult($result, $types = array(), $result_class = true, $result_wrap_class = false, $limit = null, $offset = null)

    /**
     * wrap a result set into the correct class
     *
     * @param   resource result handle
     * @param   mixed   array that contains the types of the columns in
     *                        the result set
     * @param   mixed   string which specifies which result class to use
     * @param   mixed   string which specifies which class to wrap results in
     * @param   string  number of rows to select
     * @param   string  first row to select
     *
     * @return mixed   an MDB2_Result, a MDB2 error on failure
     *
     * @access  protected
     */
    function &_wrapResult($result, $types = array(), $result_class = true,
        $result_wrap_class = false, $limit = null, $offset = null)
    {
        if ($types === true) {
            if ($this->supports('result_introspection')) {
                $this->loadModule('Reverse', null, true);
                $tableInfo = $this->reverse->tableInfo($result);
                if (PEAR::isError($tableInfo)) {
                    return $tableInfo;
                }
                $types = array();
                foreach ($tableInfo as $field) {
                    $types[] = $field['mdb2type'];
                }
            } else {
                $types = null;
            }
        }

        if ($result_class === true) {
            $result_class = $this->options['result_buffering']
                ? $this->options['buffered_result_class'] : $this->options['result_class'];
        }

        if ($result_class) {
            $class_name = sprintf($result_class, $this->phptype);
            if (!MDB2::classExists($class_name)) {
                $err =$this->raiseError(MDB2_ERROR_NOT_FOUND, null, null,
                    'result class does not exist '.$class_name, __FUNCTION__);
                return $err;
            }
            $result =new $class_name($this, $result, $limit, $offset);
            if (!MDB2::isResultCommon($result)) {
                $err =$this->raiseError(MDB2_ERROR_NOT_FOUND, null, null,
                    'result class is not extended from MDB2_Result_Common', __FUNCTION__);
                return $err;
            }
            if (!empty($types)) {
                $err = $result->setResultTypes($types);
                if (PEAR::isError($err)) {
                    $result->free();
                    return $err;
                }
            }
        }
        if ($result_wrap_class === true) {
            $result_wrap_class = $this->options['result_wrap_class'];
        }
        if ($result_wrap_class) {
            if (!MDB2::classExists($result_wrap_class)) {
                $err =$this->raiseError(MDB2_ERROR_NOT_FOUND, null, null,
                    'result wrap class does not exist '.$result_wrap_class, __FUNCTION__);
                return $err;
            }
            $result = new $result_wrap_class($result, $this->fetchmode);
        }
        return $result;
    }

    // }}}
    // {{{ function getServerVersion($native = false)

    /**
     * return version information about the server
     *
     * @param   bool    determines if the raw version string should be returned
     *
     * @return  mixed   array with version information or row string
     *
     * @access  public
     */
    function getServerVersion($native = false)
    {
        return $this->raiseError(MDB2_ERROR_UNSUPPORTED, null, null,
            'method not implemented', __FUNCTION__);
    }

    // }}}
    // {{{ function setLimit($limit, $offset = null)

    /**
     * set the range of the next query
     *
     * @param   string  number of rows to select
     * @param   string  first row to select
     *
     * @return  mixed   MDB2_OK on success, a MDB2 error on failure
     *
     * @access  public
     */
    function setLimit($limit, $offset = null)
    {
        if (!$this->supports('limit_queries')) {
            return $this->raiseError(MDB2_ERROR_UNSUPPORTED, null, null,
                'limit is not supported by this driver', __FUNCTION__);
        }
        $limit = (int)$limit;
        if ($limit < 0) {
            return $this->raiseError(MDB2_ERROR_SYNTAX, null, null,
                'it was not specified a valid selected range row limit', __FUNCTION__);
        }
        $this->limit = $limit;
        if (!is_null($offset)) {
            $offset = (int)$offset;
            if ($offset < 0) {
                return $this->raiseError(MDB2_ERROR_SYNTAX, null, null,
                    'it was not specified a valid first selected range row', __FUNCTION__);
            }
            $this->offset = $offset;
        }
        return MDB2_OK;
    }

    // }}}
    // {{{ function subSelect($query, $type = false)

    /**
     * simple subselect emulation: leaves the query untouched for all RDBMS
     * that support subselects
     *
     * @param   string  the SQL query for the subselect that may only
     *                      return a column
     * @param   string  determines type of the field
     *
     * @return  string  the query
     *
     * @access  public
     */
    function subSelect($query, $type = false)
    {
        if ($this->supports('sub_selects') === true) {
            return $query;
        }

        if (!$this->supports('sub_selects')) {
            return $this->raiseError(MDB2_ERROR_UNSUPPORTED, null, null,
                'method not implemented', __FUNCTION__);
        }

        $col = $this->queryCol($query, $type);
        if (PEAR::isError($col)) {
            return $col;
        }
        if (!is_array($col) || count($col) == 0) {
            return 'NULL';
        }
        if ($type) {
            $this->loadModule('Datatype', null, true);
            return $this->datatype->implodeArray($col, $type);
        }
        return implode(', ', $col);
    }

    // }}}
    // {{{ function replace($table, $fields)

    /**
     * Execute a SQL REPLACE query. A REPLACE query is identical to a INSERT
     * query, except that if there is already a row in the table with the same
     * key field values, the old row is deleted before the new row is inserted.
     *
     * The REPLACE type of query does not make part of the SQL standards. Since
     * practically only MySQL and SQLite implement it natively, this type of
     * query isemulated through this method for other DBMS using standard types
     * of queries inside a transaction to assure the atomicity of the operation.
     *
     * @param   string  name of the table on which the REPLACE query will
     *       be executed.
     * @param   array   associative array   that describes the fields and the
     *       values that will be inserted or updated in the specified table. The
     *       indexes of the array are the names of all the fields of the table.
     *       The values of the array are also associative arrays that describe
     *       the values and other properties of the table fields.
     *
     *       Here follows a list of field properties that need to be specified:
     *
     *       value
     *           Value to be assigned to the specified field. This value may be
     *           of specified in database independent type format as this
     *           function can perform the necessary datatype conversions.
     *
     *           Default: this property is required unless the Null property is
     *           set to 1.
     *
     *       type
     *           Name of the type of the field. Currently, all types MDB2
     *           are supported except for clob and blob.
     *
     *           Default: no type conversion
     *
     *       null
     *           bool    property that indicates that the value for this field
     *           should be set to null.
     *
     *           The default value for fields missing in INSERT queries may be
     *           specified the definition of a table. Often, the default value
     *           is already null, but since the REPLACE may be emulated using
     *           an UPDATE query, make sure that all fields of the table are
     *           listed in this function argument array.
     *
     *           Default: 0
     *
     *       key
     *           bool    property that indicates that this field should be
     *           handled as a primary key or at least as part of the compound
     *           unique index of the table that will determine the row that will
     *           updated if it exists or inserted a new row otherwise.
     *
     *           This function will fail if no key field is specified or if the
     *           value of a key field is set to null because fields that are
     *           part of unique index they may not be null.
     *
     *           Default: 0
     *
     * @return  mixed   MDB2_OK on success, a MDB2 error on failure
     *
     * @access  public
     */
    function replace($table, $fields)
    {
        if (!$this->supports('replace')) {
            return $this->raiseError(MDB2_ERROR_UNSUPPORTED, null, null,
                'replace query is not supported', __FUNCTION__);
        }
        $count = count($fields);
        $condition = $values = array();
        for ($colnum = 0, reset($fields); $colnum < $count; next($fields), $colnum++) {
            $name = key($fields);
            if (isset($fields[$name]['null']) && $fields[$name]['null']) {
                $value = 'NULL';
            } else {
                $type = isset($fields[$name]['type']) ? $fields[$name]['type'] : null;
                $value = $this->quote($fields[$name]['value'], $type);
            }
            $values[$name] = $value;
            if (isset($fields[$name]['key']) && $fields[$name]['key']) {
                if ($value === 'NULL') {
                    return $this->raiseError(MDB2_ERROR_CANNOT_REPLACE, null, null,
                        'key value '.$name.' may not be NULL', __FUNCTION__);
                }
                $condition[] = $this->quoteIdentifier($name, true) . '=' . $value;
            }
        }
        if (empty($condition)) {
            return $this->raiseError(MDB2_ERROR_CANNOT_REPLACE, null, null,
                'not specified which fields are keys', __FUNCTION__);
        }

        $result = null;
        $in_transaction = $this->in_transaction;
        if (!$in_transaction && PEAR::isError($result = $this->beginTransaction())) {
            return $result;
        }

        $connection = $this->getConnection();
        if (PEAR::isError($connection)) {
            return $connection;
        }

        $condition = ' WHERE '.implode(' AND ', $condition);
        $query = 'DELETE FROM ' . $this->quoteIdentifier($table, true) . $condition;
        $result =$this->_doQuery($query, true, $connection);
        if (!PEAR::isError($result)) {
            $affected_rows = $this->_affectedRows($connection, $result);
            $insert = '';
            foreach ($values as $key => $value) {
                $insert .= ($insert?', ':'') . $this->quoteIdentifier($key, true);
            }
            $values = implode(', ', $values);
            $query = 'INSERT INTO '. $this->quoteIdentifier($table, true) . "($insert) VALUES ($values)";
            $result =$this->_doQuery($query, true, $connection);
            if (!PEAR::isError($result)) {
                $affected_rows += $this->_affectedRows($connection, $result);;
            }
        }

        if (!$in_transaction) {
            if (PEAR::isError($result)) {
                $this->rollback();
            } else {
                $result = $this->commit();
            }
        }

        if (PEAR::isError($result)) {
            return $result;
        }

        return $affected_rows;
    }

    // }}}
    // {{{ function &prepare($query, $types = null, $result_types = null, $lobs = array())

    /**
     * Prepares a query for multiple execution with execute().
     * With some database backends, this is emulated.
     * prepare() requires a generic query as string like
     * 'INSERT INTO numbers VALUES(?,?)' or
     * 'INSERT INTO numbers VALUES(:foo,:bar)'.
     * The ? and :name and are placeholders which can be set using
     * bindParam() and the query can be sent off using the execute() method.
     * The allowed format for :name can be set with the 'bindname_format' option.
     *
     * @param   string  the query to prepare
     * @param   mixed   array that contains the types of the placeholders
     * @param   mixed   array that contains the types of the columns in
     *                        the result set or MDB2_PREPARE_RESULT, if set to
     *                        MDB2_PREPARE_MANIP the query is handled as a manipulation query
     * @param   mixed   key (field) value (parameter) pair for all lob placeholders
     *
     * @return  mixed   resource handle for the prepared query on success, 
     *                  a MDB2 error on failure
     *
     * @access  public
     * @see     bindParam, execute
     */
    function &prepare($query, $types = null, $result_types = null, $lobs = array())
    {
        $is_manip = ($result_types === MDB2_PREPARE_MANIP);
        $offset = $this->offset;
        $limit = $this->limit;
        $this->offset = $this->limit = 0;
        $result = $this->debug($query, __FUNCTION__, array('is_manip' => $is_manip, 'when' => 'pre'));
        if ($result) {
            if (PEAR::isError($result)) {
                return $result;
            }
            $query = $result;
        }
        $placeholder_type_guess = $placeholder_type = null;
        $question  = '?';
        $colon     = ':';
        $positions = array();
        $position  = 0;
        while ($position < strlen($query)) {
            $q_position = strpos($query, $question, $position);
            $c_position = strpos($query, $colon, $position);
            if ($q_position && $c_position) {
                $p_position = min($q_position, $c_position);
            } elseif ($q_position) {
                $p_position = $q_position;
            } elseif ($c_position) {
                $p_position = $c_position;
            } else {
                break;
            }
            if (is_null($placeholder_type)) {
                $placeholder_type_guess = $query[$p_position];
            }

            $new_pos = $this->_skipDelimitedStrings($query, $position, $p_position);
            if (PEAR::isError($new_pos)) {
                return $new_pos;
            }
            if ($new_pos != $position) {
                $position = $new_pos;
                continue; //evaluate again starting from the new position
            }

            if ($query[$position] == $placeholder_type_guess) {
                if (is_null($placeholder_type)) {
                    $placeholder_type = $query[$p_position];
                    $question = $colon = $placeholder_type;
                    if (!empty($types) && is_array($types)) {
                        if ($placeholder_type == ':') {
                            if (is_int(key($types))) {
                                $types_tmp = $types;
                                $types = array();
                                $count = -1;
                            }
                        } else {
                            $types = array_values($types);
                        }
                    }
                }
                if ($placeholder_type == ':') {
                    $regexp = '/^.{'.($position+1).'}('.$this->options['bindname_format'].').*$/s';
                    $parameter = preg_replace($regexp, '\\1', $query);
                    if ($parameter === '') {
                        $err =$this->raiseError(MDB2_ERROR_SYNTAX, null, null,