How to connect MongoDB with NodeJS Application!

In this blog, I going to show how to connect with MongoDB in NodeJS application.

First create root directory folder and go to terminal and install required packages.

npm install express nodemon mongodb mongoose cors dotenv

These packages are required to setup the mongoDB server.

MongoDB Account Setup

• First, create a mongoDB atlas account and create a cluster.
• After creating cluster, go to Data Service and click on connect

• After clicking connect, then popup window will appear

![mongoDb ui]](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/96gz3lje8sg19sinevoe.png)

• Click on driver to get your mongoDB connection string which look like mongodb+srv://<username>:<password>@cluster0.5hjxnse.mongodb.net/?retryWrites=true&w=majority&appName=Cluster0

Folder setup and DB connection code!

• Now create a root folder and name it as your wise. Eg: mongo-connection
• Then create a file called index.js and past the bellow code

const express = require('express');
const cors = require('cors');
const { connection } = require('./db');
require('dotenv').config();
const port = process.env.PORT 
const app = express();
app.use(cors());
app.use(express.json());

app.get('/', (req, res) => {
    res.send({
        message: 'api is working'
    })
})

app.listen(port, async()=> {
    try{
        await connection
        console.log('db is connected')
    } catch (err) {
        console.log(err.message)
    }
    console.log('server is running on port ' + process.env.PORT);
});

• Then create db.js file and setup the mongoDB

const mongoose = require('mongoose');
require('dotenv').config()

const connection = mongoose.connect(process.env.mongoUrl);

module.exports = {
    connection,
};

• In the above code we have process.env.mongoUrl, this code specifics the mongoDB connection string which was in .env environmental file.

mongoUrl = "mongodb+srv://<username>:<password>@cluster0.5hjxnse.mongodb.net/<table_name>?retryWrites=true&w=majority&appName=Cluster0"
PORT = 4000

• Don't forgot to add your current IP address in mongo atlas, while setup your DB, because mongoDB requires your system's current IP address

• If you add your current IP address, then the error will be resolve.

• So, yeah we connected our MongoDB in our NodeJS application. Now, lets test one API call to maske sure your endpoint are working.

I use tunderclient to test my API call in vscode.

• Now go to any API testing tool like postman or tunderclient to make API call to our localhost.

So, that it our server is working fine. This server run on localhost with port number 4000
http://localhost:4000/

Happy Dev!