public function rowCount()
    {
        set_error_handler(array($this->_pdooci,"errorHandler"));
        $rows = null;
        try {
            $rows = \oci_num_rows($this->_stmt);
        } catch (\Exception $e) {
            throw new \PDOException($e->getMessage());
        }
        restore_error_handler();
        return $rows;
    }