简单的猫鼬填充似乎不起作用

Simple mongoose populate doesn't seem to be working

我有以下 2 个模式

question.js

var mongoose = require('mongoose');
    var Schema = mongoose.Schema;

    var questionsSchema = new Schema({
        nr: Number,
        points: Number,
        description: String,
        isActive: {type: Boolean, required: true, default: true}
    });

    module.exports = mongoose.model('Question', questionsSchema);

round.js

 var mongoose = require('mongoose');

var Schema = mongoose.Schema;


var roundSchema = new Schema({
    name: String,
    index: Number,
    questions: {type: [Schema.Types.ObjectId], ref: 'Question'},
    createdOn: {type: Date, required: true, default: Date.now()},
    isActive: {type: Boolean, required: true, default: true}
});

module.exports = mongoose.model('Round', roundSchema);

有一些数据可以正确填充,但是当我尝试最简单的查询时,它甚至都不起作用:

var Round = require('../model/round.server.model.js');

function findAll(req, res) {
        Round.find().populate('questions').exec(function (err, results) {
            if (err) {
                console.log("An error occured when receiving all rounds!", err);
                return res.sendStatus(404);
            }
            console.log(results);
            return res.send(results);
        });
    }

检索到所有轮次,但问题数组为空,连_id本身都消失了

我认为这是因为你以错误的方式初始化你的人口。我知道您想在每一轮中提出一系列问题。你的错误似乎在这里。

 questions: {type: [Schema.Types.ObjectId], ref: 'Question'}

您应该执行以下操作才能使其正常工作:

 questions: [{type: Schema.Types.ObjectId, ref: 'Question'}]

因为实际上,您正在制作一个 type 的数组,这没有任何意义。