How to create REST API server with Node.js, Express Framwork & MongoDB database?

InstallingNode.js version 16 on Ubuntu machine

sudo apt updatesudo apt upgradesudo apt install -y curlcurl -fsSL https://deb.nodesource.com/setup_16.x | sudo -E bash -

node --version

npm --version

sudo mkdir testcd test

npm init

And, that's all! Your first node app created successfully!

touch app.js

# Main REST API framework for Nodenpm install express # Allow outside visitors to visit our servernpm install cors  # Helps to connect MongoDB with Express frameworknpm install mongoose # Helps to restart server, very handy in development modenpm install nodemon

..."scripts": {    "start": "nodemon app.js"  },...

var mongoose = require('mongoose')# Try with 127.0.0.1 if localhost do not workmongoose.connect('mongodb://127.0.0.1:27017/node_express_db', {useNewUrlParser: true, useUnifiedTopology: true}) var conn = mongoose.connection conn.on('connected', function() {    console.log('database is connected successfully')});conn.on('disconnected',function(){    console.log('database is disconnected successfully')}) conn.on('error', console.error.bind(console, 'connection error:')) module.exports = conn

var mongoose=require('mongoose')var db = require('../db/database') // create an schemavar userSchema = new mongoose.Schema({                        name:String,            email: String,            address: String,                    }); userTable=mongoose.model('users',userSchema, 'users')         module.exports = userTable

As we have created our model, we can now proceed to create some test APIs.

const express = require('express')const cors = require('cors')const mongoose = require('mongoose')const app = express()const port = 3000/*Set the cors option to access this server from outside of the world. Don't forget to limit this access when you are in production mode*/const corsOptions = {  origin: '*',  optionsSuccessStatus: 200,}app.use(cors(corsOptions));/*It will handle large amount of json body data to receive and transfer over request*/app.use(express.json({ limit: '20mb' }))app.use(express.urlencoded({ extended: false, limit: '20mb' }))//Our database connection helperconst dbConn = require('./db/database');// Our user modelconst userModel = require('./models/userModel');//-- Welcome API, our first APIapp.get('/welcome', (req, res) => {  return res.json({ code: 200, message : "Congratulations! Your Node js REST API server with Express framework and MongoDB is ready!" });});//-- Create new user APIapp.post('/createUser', async (req, res) => {  if (!Object.keys(req.body).length) {    return res.json({ status: 501, message: "No body provided" })  }  userModel.findOne({ email: req.body.email })  .then((user) => {    //------------ Checking user exists or not    if (user) return res.json({ status: 401, data: "User already exists with this phone number" })    //--- If user not created before, create now    userModel.create(req.body)    .then((result) => {        return res.json({status : 200, message : "User created successfully", result : result})    })    .catch((err) => {         return res.json({status : 501, message : "Something bad happened, Error : "+ err})    })  })  .catch((err) => {    return res.json({status : 501, message : "Something bad happened, Error : "+ err})})})//-- Show all usersapp.get("/getAllUsers", async (req, res) => {    userModel.find()    .then((result) => {        return res.json({status : 200, result : result})    })    .catch((err) => {        return res.json({status : 501, message : "Something bad happened, Error : "+ err})   })})//start node server on 3000 portapp.listen(port, () => {    console.log(`Server started successfully on port ${port}`)  })

npm start

If you see something like below then congratulations! You are successfully running Node REST API server with Express framework and MongoDB database!

Now it's time to test our newly created APIs with Postman.