编译后端开发可编程文件

Question

我正在尝试使用youtube视频将Web应用程序与数据库连接，并且当前构建数据库连接javascript文件以从表单提交并存储在数据库中。我想知道这个预期的javascript文件链接到代码的主要部分以进行编译和执行。此外，我们在哪里可以观察应用程序后端部分的输出。请帮助我摆脱这个

Youtube link: https://www.youtube.com/watch?v=ZKwrOXl5TDI
Program code for database connection is attached here
var express = require('express');
var router = require.Router();
var mongo = require('mongo');
var assert = require('assert');
console.log("testing");

var url = '';

 /* GET HOME PAGE*/
router.get('/', function(req, res, next)){
    res.render('index', { title:'tournament', condition: true, anyArray: [1,2,3] });
});
/*getting data in the database*/
router.get('/get-data', function(req, res, next){
    var resultArray = [];
/* connection of database to the form*/
    mongo.connect(url, function(err, db) {
        assert.equal(null, err);
        var cursor = db.collection('user-data').find();
        cursor.forEach(function(doc, err) {
            assert.equal(null, err);
            resultArray.push(doc);
        }, function() {
            db.close();
            res.render('index', {items: resultArray});
        });
    });
});

router.get('/insert', function(req, res, next){
    var item = {
        title: req.body.title,
        content: req.body.content,
        author: req.body.author
    };
/* connecting the database*/
    mongo.connect(url, function(err, db) {
        assert.equal(null, err);
        db.collection('user data').insertOne(item, function(err, result)) {
            assert.equal(null, err);
            console.log("data inserted");
            db.close();
        });
    });
    res..redirect('/');
});
/*updating the database*/
router.get('/update', function(req, res, next){

});
/*deleting the database*/
router.get('/delete', function(req, res, next){

});

module.exports = router;

package.json file is attached here:
{
  "name": "Tournament",
  "version": "0.0.1",
  "description": "Tournament",
  "main": "server.js",
  "scripts": {
    "start": "node server.js"
  },
  "keywords": [
    "react",
    "tutorial",
    "donation",
    "example"
  ],
  "author": "zenva",
  "license": "ISC",
  "dependencies": {
    "body-parser": "^1.14.1",
    "express": "^4.13.3",
    "mongodb": "^3.4.3"
  }
}