我是nodejs的新手，并且想使用express和nodejs连接mongo数据库。我希望数据从数据库显示到网页。

//////模型架构///////

import mongoose from 'mongoose';

const Schema=mongoose.Schema;

let Data=new Schema({     
    learningEvents:{
        type:String
    },learningactivities:{
        type:Array
    },indicators:{
        type:Array
    }
});

export default mongoose.model('Data',Data);

/////////////节点js的完整代码/////////////////

import express from 'express';
import cors from 'cors';
import bodyParser from 'body-parser';

import Data from './models/data';

import mongoose from 'mongoose';
import data from './models/data';

const app=express();
const router=express.Router();

app.use(cors());
app.use(bodyParser.json());

mongoose.connect('mongodb://localhost:27017/data');
const connection=mongoose.connection;

connection.once('open',()=>{
    console.log("Mongodb connected successfully");
});

router.route('/').get((req,res)=>{

        res.send('Hello');

    });

router.route('/data').get((req,res)=>{
    Data.find((err,Data)=>{
        if(err)
        console.log(err);
        else
        res.json(Data);

    });
});

app.use('/',router);

app.listen(4000,()=>console.log('Express server is running on port 4000'));