无限级分类

function __construct(){
        parent::__construct();

    }

public function aaaa(){
    $arr=$this->db->get("表名")->result_array();
    $list['list']=$this->sel_dg($arr,$pid=0,$level=0);
    $this->load->view("good/aaa",$list);
}

public function sel_dg($arr,$parent_id=0,$level=0){
        static $data = array();
        foreach($arr as $k=>$v) {
            if($v['parent_id']==$parent_id){
                $v['level']=$level;
                $data[]=$v;
                $this->sel_dg($arr,$v['cat_id'],$level+1);
            }
        }
        return $data;
    }

<?php echo str_repeat('      ',$v['level']);?>

<?php echo $v['cat_name']?>