Introduction

In this guide, we'll walk you through the process of setting up a basic Node.js application that interacts with a MongoDB database. You'll learn how to connect to MongoDB, perform CRUD (Create, Read, Update, Delete) operations, and build a simple RESTful API. We'll provide code examples to help you get started.


Prerequisites

Before you begin, make sure you have the following prerequisites:

  • Node.js installed on your system. You can download it from nodejs.org.
  • MongoDB installed and running locally or accessible through a connection string.
  • A code editor or integrated development environment (IDE) for writing and running Node.js applications.

Step 1: Setting Up Your Node.js Project

Start by creating a new directory for your Node.js project. Open your terminal and run the following commands:

mkdir my-node-mongodb-app
cd my-node-mongodb-app
npm init -y

This will create a new Node.js project with a 

package.json
file.


Step 2: Installing Dependencies

Next, install the required Node.js packages for MongoDB integration. Run the following command:

npm install mongodb express

This installs the 

mongodb
driver for MongoDB and 
express
for building the API.


Step 3: Creating a Connection to MongoDB

Now, you need to create a connection to your MongoDB database. In your Node.js application, create a file (e.g., 

app.js
) and add the following code:

const express = require('express');
const { MongoClient } = require('mongodb');
const app = express();
const port = 3000;
const url = 'mongodb://localhost:27017'; // MongoDB connection URL
const dbName = 'mydb'; // Your database name
const client = new MongoClient(url, { useUnifiedTopology: true });
client.connect()
    .then(() => {
        console.log('Connected to MongoDB');
    })
    .catch((err) => {
        console.error('Error connecting to MongoDB:', err);
    });
app.listen(port, () => {
    console.log(`Server is running on port ${port}`);
});

Step 4: Building Your API

You can start building your API by defining routes and handling CRUD operations. Here's an example of creating a simple "GET" endpoint to retrieve data from MongoDB:

app.get('/data', (req, res) => {
    const db = client.db(dbName);
    const collection = db.collection('mycollection'); // Replace with your collection name
    collection.find({}).toArray((err, result) => {
        if (err) {
            console.error('Error fetching data:', err);
            res.status(500).send('Error fetching data');
        } else {
            res.json(result);
        }
    });
});

Step 5: Running Your Application

To run your Node.js application, use the following command:

node app.js

Your server will start, and you can access your API at 

http://localhost:3000/data
.


Conclusion

You've successfully set up a basic Node.js application with MongoDB integration. You can expand and enhance this application to perform more advanced CRUD operations, add authentication, and create a full-fledged API.