javascript - Mongoose - 如何确定查询中是否已存在嵌套对象？

Question

我的数据库存储一个User，它有一个watchMovies[]数组，其中包含一个嵌套对象movie。

当收到包含 watchedMovie 对象的 update/put API 请求时，我想检查 movie 是否具有 id = zzz 已存在于 watchedMovie[] 数组中。

问题是，这个查询没有做到这一点。我做错了什么？

User.find(
  { username: req.params.username, 'watchedMovies.movie.id': movie.id },
  function (err, count) { 
    if (!err) exist = true;
  }
);  

完整代码如下:

架构

var userSchema = new Schema({
    username: { type: String, require: true },
    firstName: String,
    lastName: String,
    ...
    watchedMovies : [{ 
        movie: { type: Schema.Types.ObjectId, ref: 'Movie' },
        time: Date,
        watchedDuration: Number,
    }],
})

JSON 请求正文

{
    "id": "10-things-i-hate-about-you", //movie id
    "time": "2012-05-29T17:57:30.169Z",
    "watchedDuration": "88"
}

Mongoose 查询

router.put('/:username/watchedMovies', function (req, res, next) {

  //find movie
  Movie.findOne({ id: req.body.id }, function (err, movie) {

    if (err) res.send(err);

    //find if user already has the movie in the watchedMovies list
    var exist = false;
    User.find(
      { username: req.params.username, 'watchedMovies.movie.id': movie.id },
      function (err, count) { 
        if (!err) exist = true;
      }
    );   

    //if movie is already in watchedList, update User with it
    if (exist) {
      //set existing watchedMovie object
      User.update(...$set...)
    } else { // push new
      User.findOneAndUpdate(...$push...) 
    }

  });

});

Answer 1

我认为这是问题，这是你的模型

var userSchema = new Schema({
    username: { type: String, require: true },
    firstName: String,
    lastName: String,
    ...
    watchedMovies : [{ 
        movie: { type: Schema.Types.ObjectId, ref: 'Movie' },
        time: Date,
        watchedDuration: Number,
    }],
})

但是您的查询是

{ username: req.params.username, 'watchedMovies.movie.id': movie.id }

不要使用movie.id

试试这个

{ username: req.params.username, 'watchedMovies.movie': movie.id }