think php5 多表查询分页 获取总数的代码方法

控制器

	$data = input('get.');
        $info = [];
        //搜索条件
        if(!empty($data['title'])){
            $data['title'] = trim($data['title']);
            $info['topic_title'] = ['like','%'.$data['title'].'%'];
        }
        $list = BeModel::getList($info);
        $num = $list->total();//获取总数
        return $this->fetch('',[
            'list'  => $list,
            'title' => empty($data['title']) ? '' :$data['title'],
            'num'   => $num
        ]);

模型内

	$search = [];
        $search['b.status']     = ['neq',-1];
        if(!empty($data['topic_title']) ){
            $search['b.topic_title']  =  $data['topic_title'];
        }

        $res = self::alias('b')->join('subject s','s.id=b.subject_id','left')
            ->join('law l','l.id=b.law_id','left')
            ->field('b.*,s.subject,l.name')
            ->where($search)
            ->order('id asc')
            ->paginate(4,false,[
            'query' => request()->param(),
            ]);
        return $res;