递归循环

//获取当前分类下面的所有分类的特定信息信息
function get_child_cat($cat_id,$field='*',$cat_info=""){

    $where = " AND parent_id=".$cat_id." AND is_enable = 1 order by sort_order ASC";
    $catinfo = $this->get_all($field,$where);



    if(!empty($catinfo) && count($catinfo) != count($catinfo, 1)){
        foreach($catinfo as $k => $v){

            $cat_info['child'][$k]=$this->get_child_cat($v['cat_id'],$field,$v);
        }
    }
    return $cat_info;
}