Mongodb没有工作的同义词

Question

我是mongodb的初学者。我有一些问题：

      checkmongo.competition_user.find({"userid": parseInt(data.uid), "status": 1}, function(err, res) {
        if (err || !res)
            callback('failed to save');
        else {

            checkmongo.chat_message.find({"competition_id":res.competitionid}).limit(1).sort({create_date: -1}, function(err, saved) {

                if (err || !saved)
                    callback('failed to save');
                else {
                    callback(saved[0]);
                }
            });
            callback(res);
        }
    });

我希望所有竞争用户列表和最新消息详细信息都在一个对象中。这不起作用。我想这样的JSon：

    [
    {
        "_id": "564c757ce5c5487692fd3ada",
        "competition_name": "Leage 2015",
        "competitionid": 164,
        "joined_date": "2015-11-18T12:56:28.214Z",
        "status": 1,
        "userid": 1,
        "messsage":"Hi this is my first message"

    },
    {
        "_id": "564c7974e5c54876b508f7f2",
        "competition_name": "World cup leage",
        "competitionid": 167,
        "joined_date": "2015-11-18T13:13:24.200Z",
        "status": 1,
        "userid": 1,
        "messsage":"Hi this is my second message"
    }   
]

任何团体都可以在这里获得收藏链接： Collection here