3.3-node 操作 mongo

Create by fall on 18 Nov 2020
Recently revised in 27 Mar 2025

数据库操作

node 连接 mongodb 时，需要安装驱动，使用 mongodb

先从 npm 上安装 mongodb

npm install mongodb 安装驱动

建立连接

const { MongoClient } = require("mongodb");
const url = 'mongodb+srv://<user>:<password>@<cluster-url>?retryWrites=true&writeConcern=majority'
async function run() {
  try {
    await client.connect();
    // database and collection code goes here
    // find code goes here
    // iterate code goes here
  } finally {
    // Ensures that the client will close when you finish/error
    await client.close();
  }
}
run().catch(console.dir);

创建集合

const MongoClient = require('mongodb').MongoClient
const url = 'mongodb+srv://<user>:<password>@<cluster-url>?retryWrites=true&writeConcern=majority'
MongoClient.connect(url,(err,db)=>{
  if(err) throw err
  console.log('成功连接数据库')
  const dbTest = db.db('test') // 创建/使用 test 数据库
  const coll = db.collection("planets");
})

插入数据

插入单条数据

const { MongoClient } = require('mongodb')
const url = 'mongodb+srv://<user>:<password>@<cluster-url>?retryWrites=true&writeConcern=majority'
const client = new MongoClient(url)
async function run(){
  try{
    await client.connect();
    console.log('成功连接数据库')
    const dbTest = db.db('test')
    const collect = db.collection("comets");
    const addObj = { name: "fall 的笔记", url: "fallzhang.top" };
    collect.insertOne(addObj);
  }  finally {
    // 确保每次都要关闭连接
    await client.close();
  }
}
run().catch(console.dir);

插入多条数据

const {MongoClient} = require('mongodb')
const url = 'mongodb+srv://<user>:<password>@<cluster-url>?retryWrites=true&writeConcern=majority'
const client = new MongoClient(url)
async function run(){
  try {
    await client.connect();
    console.log('成功连接数据库')
    const dbTest = db.db('test')
    const addList = [
      { name: "fall 的笔记", url: "fallzhang.top" },
      { name: "fall 的 github", url: "github.com/fall-zhang" }
    ];
    const result = dbTest.collection("underWare").insertMany(addList);
    console.log(result.insertedIds)
  } finally {
    // 确保每次都要关闭连接
    await client.close();
  }
}
run().catch(console.dir);

更新数据

const {MongoClient} = require('mongodb')
const url = 'mongodb+srv://<user>:<password>@<cluster-url>?retryWrites=true&writeConcern=majority'
const client = new MongoClient(uri);
async function run() {
  try {
    await client.connect();
    // 使用数据库和集合
    const collect = db.db('test').collection('underWare')
    // 更新一条数据(查找到的第一条数据)
    underWare.updateOne({ type: "cn" },{$set: { "url" : "全部都清空" }})
    // 更新多条数据
    const upManyResult = underWare.updateMany({}，{ $mul: {
      radius: 1.60934
 		 }})
    // 操作的数量
    console.log('upManyResult count: ', upManyResult.modifiedCount)
  } finally {
    // Ensures that the client will close when you finish/error
    await client.close();
  }
}
run().catch(console.dir);

删除数据

const { MongoClient } = require("mongodb");
const uri =
  "mongodb+srv://<user>:<password>@<cluster-url>?retryWrites=true&writeConcern=majority";
const client = new MongoClient(uri);
async function run() {
  try {
    await client.connect();
    // 使用数据库和集合
    const db = client.db("sample_guides");
    const coll = db.collection("comets");
    // 删除多个数据
    const doc = {
      orbitalPeriod: {
        $gt: 5,
        $lt: 85
      }
    };
    const result = await coll.deleteMany(doc);
    // 删除的数量
    console.log("Number of documents deleted: " + result.deletedCount);
  } finally {
    await client.close();
  }
}
run().catch(console.dir);

数据查询

简单查询

• 如果不指定任何查询运算符，驱动程序将以 AND（且）方式解释您的条件。

const { MongoClient } = require("mongodb");
// Replace the uri string with your MongoDB deployment's connection string.
const uri =
  "mongodb+srv://<user>:<password>@<cluster-url>?retryWrites=true&writeConcern=majority";
const client = new MongoClient(uri);
async function run() {
  try {
    await client.connect();
     // 使用数据库和集合
    const db = client.db("sample_guides");
		const coll = db.collection("planets");
     // 查询数据
    const cursor = coll.find({ hasRings: true });
    // 对数据进行迭代
    await cursor.forEach(console.log);
  } finally {
    // Ensures that the client will close when you finish/error
    await client.close();
  }
}
run().catch(console.dir);

复杂查询

const { MongoClient } = require("mongodb");
// Replace the uri string with your MongoDB deployment's connection string.
const uri = "mongodb+srv://<user>:<password>@<cluster-url>?retryWrites=true&writeConcern=majority";
const client = new MongoClient(uri);
// 复杂查询
async function query() {
  try {
    await client.connect();
     // 使用数据库和集合
    const db = client.db("sample_guides");
		const coll = db.collection("planets");
     // 查询数据，surfaceTemperatureC.mean 小于 15
    const cursor = coll.find({ "surfaceTemperatureC.mean": { $lt: 15 } });
     // 条件查询，且。查询大于 2，小于 5
    const cursor2 = coll.find({
  		$and: [{ orderFromSun: { $gt: 2 } }, { orderFromSun: { $lt: 5 } }],
		});
    // 条件查询，大于 7 或 小于 2。
    const cursor = coll.find({
      $or: [{ orderFromSun: { $gt: 7 } }, { orderFromSun: { $lt: 2 } }],
    });
    // 对数据进行迭代
    await cursor.forEach(console.log);
  } finally {
    // Ensures that the client will close when you finish/error
    await client.close();
  }
}
query().catch(console.dir);