mongodb 模型.updateOne()在Document.save()- mongoose.js之前执行

ui7jx7zq  于 2022-11-28  发布在  Go
关注(0)|答案(3)|浏览(155)

我正在学习使用MongoDB和mongoose.js。我想插入一个文档并更新它。当我运行app.js时,它会记录“已成功更新”,但当我在mongo shell中预览它时,没有任何修改,即:“美丽的红色”保持不变。

const mongoose = require('mongoose');

// Connection URL
const url = 'mongodb://localhost:27017/fruitsDB'; //creates fruitsDB

// Connect to database server
mongoose.connect(url, {
  useNewUrlParser: true,
  useUnifiedTopology: true
});

// Define a schema/table structure
const fruitSchema = new mongoose.Schema({
  name: {
    type: String,
    required: [true, "No name specified. Try Again!"] //validation with error message
  },
  rating: {
    type: Number,
    min: 1, //validation
    max: 10 //validation
  },
  review: String
});

// Create a model from the structure
const Fruit = mongoose.model("Fruit", fruitSchema);

// Create a document that follows a model
const fruit = new Fruit({
  name: "Apple",
  rating: 6,
  review: "Pretty Red."
});

// Save the new document/entry
fruit.save();

// Update single document
Fruit.updateOne({name: "Apple"}, {review: "Review Changed!"}, function(err) {
  if(err) {
    console.log(err);
  } else {
    console.log("Successfully updated.");
  }
});
f2uvfpb9

f2uvfpb91#

save()返回一个承诺,等待它执行。
https://mongoosejs.com/docs/promises.html

brc7rcf0

brc7rcf02#

我猜你需要像这样使用$set:

// Mongoose sends a `updateOne({ _id: doc._id }, { $set: { name: 'foo' } })`

文档:https://mongoosejs.com/docs/documents.html#updating
对于您的案例:

Fruit.updateOne({name: "Apple"}, { $set : {review: "Review Changed!"}}, function(err) {
  if(err) {
    console.log(err);
  } else {
    console.log("Successfully updated.");
  }
});
31moq8wy

31moq8wy3#

是的,这是等待从www.example.com()返回的承诺的问题document.save;在mongoDB中,每次您处理数据库时,如create、findOne、updateOne、delete等,这些都返回承诺,您将不得不等待它们。

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