protected function _get_child($id) { $curr = M('column')->find($id); $column = M('column')->where(array('status = 0'))->select(); import('Class.Category', APP_PATH); $data = \Service\Category::getChildrenById($column, $curr['id']); $retVal = !empty($data) ? implode(',', $data) . ',' . $id : $id; return $retVal; }