thinkphp5.0.20多表联查以及分页

直接上代码，大家可以参考下

    public function collectWorkList()
    {
        $user_id = input('param.user_id');

        //当前页码,默认为第一页
        $pageNum = empty(input('param.pageNum')) ? 1 : input('param.pageNum');
        //每页数量
        $numPerPage = 8;


        //测试数据
        // $user_id = 1;
        // $pageNum = 1;
        // $numPerPage = 1;


        if(empty($user_id)){
            $result['code'] = 2;
            $result['msg'] = '暂无用户信息！';
            return json($result);
        }

        //起始数据
        $index = ($pageNum-1)*$numPerPage;

        $where['a.user_id'] = $user_id;
        $where['a.is_cancel'] = 0;

        $now = Db::table('user_collect a')
            ->join('work b','a.work_id=b.id','LEFT')
            ->where($where)
            ->order(['b.is_urgent'=>'desc','b.addtime'=>'desc'])
            ->field('a.id,a.work_id,a.addtime,b.title,b.detailaddress,b.work_time,b.is_urgent,b.cost_type,b.cost,b.addtime baddtime')
            ->limit($index,$numPerPage)
            ->select();

        $total = Db::table('user_collect a')
            ->join('work b','a.work_id=b.id','LEFT')
            ->where($where)
            ->order(['b.is_urgent'=>'desc','b.addtime'=>'desc'])
            ->count('a.id');

        $nowTotal = count($now);

        if($nowTotal>0){
            foreach ($now as $k=>$v){
                $danwei = $v['cost_type'] == 0 ? '小时' : ($v['cost_type'] == 1 ? '其他' : '月');
                $now[$k]['newPrice'] = "{$v['cost']}元/{$danwei}";
            }
        }
        $result['total'] = $total;
        $alreadyLoad = ($pageNum-1)*$numPerPage + $nowTotal;
        if($nowTotal>0){
            if($total-$alreadyLoad<=0){
                $result['havenums'] = 0;
            }else{
                $result['havenums'] = $total-$alreadyLoad;
            }
            $result['collectList'] = $now;
            $result['code'] = 1;
        }else{
             $result['collectList'] = [];
            $result['code'] = 2;
        }

        return json($result);

    }