node express 操作mongodb

1. 创建文件夹 并在文件夹下运行 npm init -y
2. 安装express以及mongodb npm install express --save npm install mongodb --save npm install body-parser --save
3. demo

const express = require("express");
const app = express();
const {MongoClient} = require("mongodb");
const url = "mongodb://localhost:27017";
const db = "test";

const bodyParser = require('body-parser');
app.use(bodyParser.json());
app.listen(8089);

app.get("/:username",(req,res)=>{
    MongoClient.connect(url,{ useUnifiedTopology: true },(error,client)=>{
        let username = req.params["username"]
        console.log(username);
        let dbs = client.db(db);
        dbs.collection('uset').find({"username":username}).toArray((err,result)=>{
            res.send(result)
        });
        
    })
});

app.post("/insert",(req,res)=>{
    console.log(req.body);
    MongoClient.connect(url,{ useUnifiedTopology: true },(error,client)=>{
        let dbs = client.db(db);

        dbs.collection('uset').insertOne(req.body);
        res.send("success")
    })
})