$where=[];//筛选条件数组

     if(input('cate_id')){

        $where[] = [

                     ['a.cate_id', '=', $cate_id],

                 ];

     }

     if(input('searchkey')){

        $where[] = [

                     ['title', 'like', '%'.$searchkey.'%'],

                 ];

     }

     $archivesData=Db::name('archives')->alias('a')->

            field('a.id,a.title,a.listorder,b.cate_name,a.time')->

            join('category b','a.cate_id=b.id')->

            where($where)->

            order('a.listorder asc')->//小到大

            order('a.id DESC')->//大-》小

            paginate([

              'list_rows'=> 3,//每页数量

              'query' => request()->param(),

              ]);