Question

这是课程和主题的模型，我想在猫鼬的帮助下在课程中填充主题。当我们调用 API 时，我想要的是课程和主题的联合结果。

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

let courseSchema = new Schema({
  course_id: {
    type: Number
  },
  course_title: {
    type: String
  },
  course_description: {
    type: String
  },
  course_duration:{
    type: Number
  },
  topic:{
    type: mongoose.Schema.Types.ObjectId,
    ref: "Topic"
  }
}, {
    collection: "courses"
  })

  let topicSchema = new Schema({
    topic_id: {
        type: Number
    },
    topic_title: {
        type: String
    },
    topic_description: {
        type: String
    }               
}
    ,{
        collection: "topics"
    })

const Topic = mongoose.model("Topic", topicSchema)
const Course = mongoose.model('Course', courseSchema)
module.exports = { Topic, Course };

这是GET的API，我也用populate但是不能得到课程和主题的联合结果。

let mongoose = require('mongoose'),
express = require('express'),
router = express.Router();
var { Topic, Course }= require('../models/Course')
    router.route('/').get((req, res) => {
      Course.find().populate('topic').exec((error, data) => {
        if (error) {
          return next(error)
        } else {
          res.json(data)
        }
      })
    })

我想要这样的输出：

{
        "_id": "5fea9d7cd6651122e04ce5ed",
        "course_id": 2,
        "course_title": "GOlang",
        "course_description": "google ",
        "course_duration": 11,
        "topic_id": 3,
        "topic_title": "hoisting",
        "topic_description": "variable and function",
        "__v": 0
    }

Answer 1

你为什么这样做？

   router.route('/').get((req, res) => {
  Course.find().populate('topic').exec((error, data) => {
    if (error) {
      return next(error)
    } else {
      res.json(data)
    }
  })
})

而不是这个吗？

   router.get('/',(req, res) => {
  Course.find().populate('topic').exec((error, data) => {
    if (error) {
      return next(error)
    } else {
      res.json(data)
    }
  })
})

在猫鼬中填充未按预期工作

1 个答案: