thinkphp排序时，按下级类别数量多的排在前面的写法

            $exp =new \think\db\Expression('(SELECT count(*) from `news` where `news`.`comid` = `company`.`comid`) DESC');
            $entlist = Db::name('company')
                ->join('news','company.comid=news.comid')->order($exp)
                ->group('news.comid')
                ->paginate(12,false,['query'=>request()->param()]);