phpstock/app/admin/controller/Cat.php

<?php

namespace app\admin\controller;

use app\BaseController;
use think\App;
use think\facade\Db;

class Cat extends BaseController
{
public $post="";
public function __construct(App $app)
{
    parent::__construct($app);
    $this->post=$this->request->post();
}
public function list(){
    $where=[];
    $pid =  isset($this->post['pid']) &&$this->post['pid']!=="" ?intval($this->post['pid']): "";
    if($pid!==""){
        $where[]=["pid","=",$pid];
    }
    $cat_name=isset($this->post['cat_name']) && $this->post['cat_name'] !==""? intval($this->post['cat_name']) :"";
    if($cat_name!==""){
        $where[]=['cat_name',"like","%$cat_name%"];
    }
    $list = Db::name('cat')->where(['pid'=>$pid])->select();
    $item=[];
    foreach ($list as $value) {
        $str = Db::name('cat')->where(['pid' => $value['id']])->select();
        $item[]=$str;
        foreach ($str as $stn) {
            $var = Db::name('cat')->where(['pid' => $stn['id']])->select();
//            $item[]=$var;
        }
    }
//    $data=[];
//    $db=Db::name('')
    return app_show(0,"获取成功",$item);
}
}