Node.js 后端开发之使用 Mongoose 连接 MongoDB 数据库

Hello World

配置文件：

.env
MONGO_URI='xxx'

服务端：

// server.js
const express = require("express");
const mongoose = require('mongoose')
const dotenv = require('dotenv')
const app = express();
dotenv.config();

// 连接 MongoDB
mongoose.connect(process.env.MONGO_URI, { useNewUrlParser: true, useUnifiedTopology: true })
  .then(() => {
    console.log('Connected to MongoDB');
  })
  .catch((err) => {
    console.error('MongoDB Connection Error:', err);
  });

// 设置 Schema（表模板）
const personSchema = new mongoose.Schema({
  name: { type: String, required: true },
  age: Number,
  favoriteFoods: [String]
});

// 生成 Model（表）
const Person = mongoose.model("Person", personSchema);

// 添加中间件，用于解析请求体
app.use(express.json());
app.use(express.urlencoded({ extended: true }));

// 处理路由
app.post('/new', async (req, res) => {
  try {
    let person = req.body;
    console.log('Request Body:', person);
    person = new Person(person);
    const result = await person.save();  // 需要等待操作完成
    res.json(result);
  } catch (err) {
    console.error('Error: ', err.message);
    res.status(500).json({
      error: 'Server Error',
      message: err.message
    });
  }
});

const port = 3000;
app.listen(port, () => {
  console.log(`Server is running on port ${port}`);
});

使用 Axios 发送一个请求：

// client.js
const axios = require('axios');

const data = {
  name: "Jane Fonda",
  age: 84,
  favoriteFoods: ["eggs", "fish", "fresh fruit"]
};

axios.post('http://localhost:3000/new', data)
  .then(response => {
    console.log('Response:', response.data);
  })
  .catch(error => {
    console.error('Error:', error.response.data);
  });

常用函数

Model.deleteMany()
Model.deleteOne()
Model.find()
Model.findById()
Model.findByIdAndDelete()
Model.findByIdAndRemove()
Model.findByIdAndUpdate()
Model.findOne()
Model.findOneAndDelete()
Model.findOneAndReplace()
Model.findOneAndUpdate()
Model.replaceOne()
Model.updateMany()
Model.updateOne()

参见：Queries

链式搜索：

Model.find({ age: 55 })
  .sort({ name: -1 })
  .limit(5)
  .select({ favoriteFoods: 0 })
  .exec((error, data) => {
    //do something here
  });

参见：Chain Search Query Helpers to Narrow Search Results | freeCodeCamp.org

Mongoose 参考文档：Mongoose: Getting Started