protected function insertBatch( $table, $rows ) {

        $columns = $this->getColumns( $rows );
        if ( empty( $columns ) ) return;

        $query = $this->insertHead( $table, $columns );
        $lists = $this->valueLists( $rows, $columns );
        $query .= implode( ", ", $lists );

        $this->onQuery( $query );

        $statement = $this->prepare( $query );
        $statement->execute();

        return $statement;

    }