private function content_type_query($controller, $format) { $table = $controller . '_type'; $column = $controller . '_type_id'; $where = $controller . "_type_name"; $field = array($format); //build single query from BuildQuery class $db_results = BuildQuery::single_field_query($table, $column, $where, $field); $db_result = $db_results[$column]; self::$db_content_type = $db_result; }