javascript - Mongoose:在数组中填充对象时出现问题

Question

我有以下三个模型:

var User = {
first_name: String,
last_name: String,
}

var Student = {
role = String,
user = {type: mongoose.Schema.Types.ObjectId, ref: 'User'}
groups = [{type: mongoose.Schema.Types.ObjectId, ref: 'Group'}],
}

var Group = {
name = String,
students = [{type: mongoose.Schema.Types.ObjectId, ref: 'Student'}],
}

我的快速获取方法如下所示:

router.route('/')
  .get(function(req, res){
    Group.find().populate('students').exec(function(err, groups){
      res.json(groups);
    });

我的 json 对象返回填充的学生对象 a 的数组，但我只从每个学生对象中接收 user._id 。我怎样才能填充用户对象？任何信息都会很棒!谢谢

Answer 1

您可以跨多个级别进行填充:

router.route('/')
  .get(function(req, res){
    Group
      .find()
      .populate({
        path: 'students',
        // Get the student's user ids
        populate: { path: 'user' }
      })
      .exec(function(err, groups){
        res.json(groups);
      });

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