首先安装mongodb包
cnpm install mongodb
在文件中导入mongodb包
var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017";
const db_name = "classWeb";
连接数据库
MongoClient.connect(url, (err, client) => {
//连接db_name这个数据库并使用student这张表
const collection = client.db(db_name).collection('user');
collection.find().toArray((err, result