protected function _buildQueryElementConcatId() { $str = parent::_buildQueryElementConcatId(); $jointable = $this->getJoinModel()->getJoin()->table_join; $dbtable = $this->actualTableName(); $db = JFactory::getDbo(); $table =& $this->getListModel()->getTable(); $fullElName = $this->getFullName(false, true, false) . "_id"; $str .= ", (SELECT GROUP_CONCAT(" . $this->_element->name . " SEPARATOR '" . GROUPSPLITTER . "') FROM {$jointable} WHERE parent_id = " . $table->db_primary_key . ") AS {$fullElName}"; return $str; }