How to connect MongoDB with ReactJS ?

Connecting MongoDB with React is an important task for making full-stack applications and web apps with databases. A well-liked NoSQL database called MongoDB offers a scalable and adaptable way to store and retrieve data. You might need to establish a connection to a MongoDB database while using ReactJS to create a web application in order to get and modify data.

Approach to connect MongoDB with ReactJS

We must first establish a server-side connection to MongoDB in order to interact with it. Then, from the ReactJS client, we must access APIs to communicate with MongoDB. Let’s divide the procedure into two primary steps: establishing the server-side connection and utilizing the ReactJS client to make API calls.

Prerequisite

• React JS
• Node JS
• Mongo DB

Steps to Connect MongoDB with React JS

Create React App

To build a React application follow the below steps:

Step 1: Create a react application using the following command  

npx create-react-app foldername

Step 2: Once it is done change your directory to the newly created application using the following command  

cd foldername

Step to run the application: Enter the following command to run the application.

npm start

Backend Setup With NodeJS

Setup NodeJs for Backend to integrate with frontend:

Step1: Make a folder in the root directory using the following command

mkdir backend

Step 2: Once it is done change your directory to the newly created folder called backend using the following command

cd backend

Step 3: Run the following command to create configure file

npm init -y 

Step 3: Now Install the mongoose MongoDB using the following command.

npm i express mongoose mongodb cors

Step 4: Create a file that is index.js

touch index.js

Step to run the application: Enter the following command to run the application.

nodemon index.js 

Application Structure

Dependencies list for frontent server.

{
    "name": "mongosetup",
    "version": "0.1.0",
    "private": true,
    "dependencies": {
        "@testing-library/jest-dom": "^5.17.0",
        "@testing-library/react": "^13.4.0",
        "@testing-library/user-event": "^13.5.0",
        "react": "^18.2.0",
        "react-dom": "^18.2.0",
        "react-scripts": "5.0.1",
        "web-vitals": "^2.1.4"
    }
}

Dependencies list for backend server.

"dependencies": {
        "cors": "^2.8.5",
        "express": "^4.18.2",
        "mongodb": "^6.1.0",
        "mongoose": "^7.6.1"
}

Example: Import and configure mongo in the backend/index.js file and create a form in react App.js component to link the mongo with front end

JavaScript

// Code  for mongoose config in backend
// Filename - backend/index.js

// To connect with your mongoDB database
const mongoose = require('mongoose');
mongoose.connect('mongodb://localhost:27017/', {
    dbName: 'yourDB-name',
    useNewUrlParser: true,
    useUnifiedTopology: true
}, err => err ? console.log(err) :
    console.log('Connected to yourDB-name database'));

// Schema for users of app
const UserSchema = new mongoose.Schema({
    name: {
        type: String,
        required: true,
    },
    email: {
        type: String,
        required: true,
        unique: true,
    },
    date: {
        type: Date,
        default: Date.now,
    },
});
const User = mongoose.model('users', UserSchema);
User.createIndexes();

// For backend and express
const express = require('express');
const app = express();
const cors = require("cors");
console.log("App listen at port 5000");
app.use(express.json());
app.use(cors());
app.get("/", (req, resp) => {

    resp.send("App is Working");
    // You can check backend is working or not by
    // entering http://loacalhost:5000

    // If you see App is working means
    // backend working properly
});

app.post("/register", async (req, resp) => {
    try {
        const user = new User(req.body);
        let result = await user.save();
        result = result.toObject();
        if (result) {
            delete result.password;
            resp.send(req.body);
            console.log(result);
        } else {
            console.log("User already register");
        }

    } catch (e) {
        resp.send("Something Went Wrong");
    }
});
app.listen(5000);

Javascript

// Frontend code
// Filename - App.js
// Filename - App.js

import { useState } from 'react'
function App() {
    const [name, setName] = useState("");
    const [email, setEmail] = useState("");
    const handleOnSubmit = async (e) => {
        e.preventDefault();
        let result = await fetch(
        'http://localhost:5000/register', {
            method: "post",
            body: JSON.stringify({ name, email }),
            headers: {
                'Content-Type': 'application/json'
            }
        })
        result = await result.json();
        console.warn(result);
        if (result) {
            alert("Data saved succesfully");
            setEmail("");
            setName("");
        }
    }
    return (
        <>
            <h1>This is React WebApp </h1>
            <form action="">
                <input type="text" placeholder="name"
                value={name} onChange={(e) => setName(e.target.value)} />
                <input type="email" placeholder="email"
                value={email} onChange={(e) => setEmail(e.target.value)} />
                <button type="submit"
                onClick={handleOnSubmit}>submit</button>
            </form>

        </>
    );
}

export default App;

Step to run the application:

Step 1: Enter the following command to run the application in Project directory.

npm start

Step 2: Use this command in backend directory to run backend server

nodemon index.js

Output: This output will be visible on https://localhost:3000/ on browser and inside mongo Database.

successfully connected ReactJs and MongoDB

We connected the React app with MongoDB Database. We take two inputs which are name and email from a user by React app running on 3000 port and then we call the API created by express and NodeJs and send the data to the MongoDB database.