Hello, my friend. If you don’t know me, my name is Aryan Gupta, a passionate web developer and Node.js developer who’s making very specific questions on the internet and not finding answers.

As you begin your journey in creating a backend with express and Node js, you will encounter many challenges, one of which is how to connect the database to your backend. That is what I will demonstrate to you today, and we will also add data to the database. You must have a basic understanding of Node js and express to follow along with this tutorial.

To begin, we will use MongoDB as our database. Firstly

What is MongoDB?

MongoDB is a document-oriented, open-source database management system that is often used for handling large amounts of data. It uses a JSON-like format to store data and is based on the NoSQL (not only SQL) model, which allows for more flexible and scalable data management compared to traditional relational databases.

Now, let's start

First, make a folder you can name anything. I am naming it the backend

mkdir backend
cd backend

Now In the backend folder we do

npm init -y

This command will make a package.json file which will look like this

Wrote to C:\Users\gupta\OneDrive\Desktop\backend\package.json:

{
  "name": "backend",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC"
}

Now make file server.js in the backend where we will write all the server logic

Let's install all the necessary dependencies we need for this tutorial

npm install express cors body-parser 
npm install -d nodemon

After installing all dependencies Now let's set up the server.js file like this

const express = require("express");
const cors = require("cors");
const bodyParser = require("body-parser");
const templateRoute = require("./routes/template");
const app = express();
const port = 8001;
// const csrfMiddleware=csurf({cookie:true});

app.use(
  cors({
    origin: [
      "https://www.uniqusstore.io",
      "https://www.google.com/",
      "http://localhost:3000",
    ],
  })
);
app.use(express.json());
app.use(bodyParser.json());
app.use(express.urlencoded({ extended: false }));
//creating template route
app.use("/template", templateRoute);

//home route
app.get("/", (req, res) => {
  res.json({ message: "Welcome to MongoDB Turorial" });
});

// Backend is listing on 8001
app.listen(port, () => {
  console.log(`app runing on port ${port}`);
});

Above will be our server js file

Here we used CORS (Cross-Origin Resource Sharing). This is done to prevent malicious websites from making unauthorized requests on behalf of the user. we have given access to localhost:3000 where our frontend will run

In your package.json do this changes to set up nodemon

  "scripts": {
    "dev": "nodemon server.js"
  },

Now let's run our server

npm run dev

We used mongoose to connect to our database

const mongoose = require("mongoose");
mongoose.set("strictQuery", false);
mongoose
  .connect( "mongodb+srv://uniqus<password>@uniqusstore.nvafzrk.mongodb.net/?retryWrites=true&w=majority"
  )
  .then(() => console.log("DB Connected!"));

you can get the URL by making an account in mongoDB altas by going to this link - https://www.mongodb.com/atlas/database

finish the setup procedures Following that, you will select the free mongodb shared plan .

Choose the default settings, name your cluster whatever you want, and then click Create Cluster.

Create a username and password, and remember the password as it is critical when connecting to the cluster.

Choose to Add My Current IP Address to obtain your machine's IP address, then click Finish and close.

You will now see this screen after your cluster has been created.

Connect by clicking the connect button.

Select Connect your application now.

Copy and paste the URL In server js mongoose.connect, replace "<password>" with the password you created earlier.

With this again run the server and your database will be connected

mongoose
  .connect( "mongodb+srv://uniqusexamplePassword@uniqusstore.nvafzrk.mongodb.net/?retryWrites=true&w=majority"
  )
  .then(() => console.log("DB Connected!"));

npm run dev

Your database is now linked to your backend. Now you can perform all database operations. In my next blog, I will show you how to add data to a database and perform various database operations.

Thank you for reading, and please continue to learn.