laravel 子查询

laravel 子查询使用

 $sql = DB::table('project')
            ->select('project_id','subject_id','user_id');

        $join = DB::table('subject_info as si')
            ->joinSub($sql,'p',function($query){
                $query -> on("p.subject_id","=","si.subject_id");
            })
            ->leftJoin('member as m','m.id','=','p.user_id')
            ->select('p.*','si.subject_name','m.username')
            ->get();