如何添加新的 object 或推入數組 Mongodb Compass NodeJS Express（更新不是功能）？

Question

此時我嘗試查找在這種情況下有效的查詢，但隨后想更新 object。 所以我想檢查審查 object 是否存在，如果不存在，則首先創建該鍵名，然后將該 object 推送到數組中。 否則推入現有的 object 陣列中。

默認 object 看起來像（沒有評論對象）：

 const mongoose = require('mongoose'); const musicSchema = mongoose.Schema({ id: { type: Number, required: true }, artist: { type: String, required: true }, title: { type: String, required: true }, release_year: { type: Number, required: true }, genre_id: { type: Number, required: true }, image_url: { type: String, required: true }, reviews: [{ id: { type: Number, required: true }, locale: { type: String, required: true }, rating: { type: Number, required: true }, comment: { type: String, required: true } }] }); const Music = mongoose.model("Music", musicSchema); // now we have to create our model console.log; module.exports = Music; // export our created model

 app.post('/addReview/:id', async (req, res) => { let idNumber = parseInt(req.params.id); // 501437 let reviewObject = req.body; // {id: "501437", locale: "nl", rating: 3, text: "helello"} try { const music = client.db('database').collection('music'); const query = { id: idNumber }; const musicSong = await music.findOne(query); await musicSong.update({ $push: { reviews: reviewObject } }); // error comes from here } catch (err) { console.log(err); } });

Answer 1

• 檢查reviews字段是否不存在，然后將其初始化為空白數組
• 將 object 推送到reviews
• save()保存主文檔

app.post('/addReview/:id', async (req, res) => {
  let idNumber = parseInt(req.params.id);  // 501437
  let reviewObject = req.body; // {id: "501437", locale: "nl", rating: 3, text: "helello"}
  try {
    const music = client.db('database').collection('music');
    const query = { id: idNumber };
    let musicSong = await music.findOne(query);
    if (!Array.isArray(musicSong.reviews)) {
      musicSong.reviews = [];
    }
    musicSong.reviews.push(reviewObject);
    music.save();
  } catch (err) {
    console.log(err);
  }
});

---

使用updateOne()的第二個選項：

如果您使用更新方法，則不需要查找、檢查和保存操作，

app.post('/addReview/:id', async (req, res) => {
  const query = { id: parseInt(req.params.id) };
  let reviewObject = req.body;
  try {
    const music = client.db('database').collection('music');
    await music.updateOne(query, { $push: { reviews: reviewObject } });
  } catch (err) {
    console.log(err);
  }
});