在server.js中，您传递了一个空对象，您需要在其中传递数据库作为第二个参数，这是您的route / index.js导出函数所期望的。
PFB更新了server.js：
const express = require('express');const MongoClient = require('mongodb').MongoClient;const bodyParser = require('body-parser');const db = require('./config/db');const app = express();const port = 8000;app.use(bodyParser.urlenpred({extended:true}));MongoClient.connect(db.url,(err,database) =>{ if (err) return console.log(err) //require('./app/routes')(app,{}); //check below line changed require('./app/routes')(app, database); app.listen(port,() => { console.log("We are live on"+port); });});
