public function index(){

     $sql = "";

     $list = "";

     $pagenumber = 20;//默认分页条数

     //查询数据

     $list = Db::name('wcmall_type','id,name,sort')->where($sql)->order('sort asc')->paginate($pagenumber,false,['query'=>request()->param()])->each(function($item, $key){

         $wctypeid = $item["id"]; //获取数据集中的id

         $num = Db::name('wcmall_type_attribute')->where("wctypeid='$wctypeid'")->count('id'); //根据ID查询相关其他信息

         $item['num'] = $num; //给数据集追加字段num并赋值

         return $item;

     });

     $page = $list->render();

     return view('type/index',['list'=>$list,'page'=>$page,'title'=>'商品类型']);

 }