Horde_Db_Adapter_Pdo_Base::beginDbTransaction PHP Method

    public function beginDbTransaction()
    {
        if (!$this->_transactionStarted) {
            try {
                $this->_connection->beginTransaction();
            } catch (PDOException $e) {
                throw new Horde_Db_Exception($e);
            }
        }
        $this->_transactionStarted++;
    }