$newsData = Db::table("ven_activity")

            ->alias('a')

            ->join('ven_activitycate w','a.cid=w.id')

            ->where("a.status=1 and a.cid=28")

            ->field("a.id,a.title,a.faceimg,a.time_report,a.resume,a.cid,w.name")

            ->order('a.id DESC')

            ->paginate(25);

        //判断数据是否为空

        $data = $newsData->toArray()['data'];//处理办法

        if($data){

            $this->assign('a','1');//用此参数在模板页面判断

        }

        $this->assign('newsData',$newsData);