📂 Node.js – MongoDB: Introduction & Setup – Connect and Create NoSQL Databases

🧲 Introduction – Why Use MongoDB with Node.js?

MongoDB is a flexible, document-oriented NoSQL database that stores data in JSON-like structures. Combined with Node.js, it becomes a powerful backend stack for scalable and modern web applications—ideal for REST APIs, real-time apps, and data-driven UIs.

🎯 In this guide, you’ll learn:

• How to install and set up MongoDB for Node.js
• How to use the official MongoDB Node.js driver
• How to create a database and collections programmatically

📘 Topics Covered

⚙️ Node.js – MongoDB Get Started

🔹 Prerequisites

✅ You’ll need:

• Node.js installed (node -v)
• MongoDB installed locally OR a cloud account (MongoDB Atlas)
• A project directory with npm init -y run

🔹 Step 1: Install MongoDB Driver

npm install mongodb

This installs the official mongodb Node.js driver.

🔹 Step 2: Connect to MongoDB

Create db.js:

const { MongoClient } = require('mongodb');
const uri = 'mongodb://localhost:27017'; // For Atlas, use the full connection string

const client = new MongoClient(uri);

async function connectDB() {
  try {
    await client.connect();
    console.log('MongoDB Connected!');
  } catch (err) {
    console.error('Connection failed:', err);
  }
}

connectDB();

module.exports = client;

🧪 Output:

MongoDB Connected!

✅ Replace localhost with Atlas URI if using the cloud version.

🛠️ Node.js – MongoDB Create Database / Collections

🔹 Step 3: Create Database & Collection

Create createCollection.js:

const client = require('./db');

async function createCollection() {
  const db = client.db('myCompany');
  await db.createCollection('employees');
  console.log('Collection created!');
}

createCollection();

🧪 Output:

Collection created!

✅ MongoDB auto-creates the database (myCompany) and collection (employees) on first insert.

🔹 Step 4: Insert Sample Document

async function insertSample() {
  const db = client.db('myCompany');
  const result = await db.collection('employees').insertOne({
    name: "Alice",
    position: "HR",
    salary: 50000
  });
  console.log("Document ID:", result.insertedId);
}

insertSample();

🧪 Output:

Document ID: 64aefb1b48ef47e344d9a123

✅ No need to define schema in MongoDB. Documents are flexible and dynamic.

📌 Summary – Recap & Next Steps

MongoDB is a schema-less, document-based database that fits perfectly with the asynchronous nature of Node.js. You can quickly connect, create databases/collections, and start inserting data—all with just a few lines of code.

🔍 Key Takeaways:

• Use the mongodb driver to connect to MongoDB from Node.js
• db.createCollection() defines a collection inside a database
• Documents are inserted as plain JavaScript objects
• MongoDB is ideal for JSON-style, nested, and flexible data storage

⚙️ Real-World Uses:

• Building RESTful APIs (users, posts, orders, products)
• Saving chat logs or activity streams
• Managing flexible form submissions and IoT data

❓ Frequently Asked Questions

❓ Can I use MongoDB without installing it locally?
✅ Yes, use MongoDB Atlas – a cloud-hosted version with free tiers.

❓ How do I create a database in MongoDB?
✅ Just reference it via client.db('name'). MongoDB will create it when you write to it.

❓ Is MongoDB schema-less?
✅ Yes. Collections can store documents with varying structures, making it highly flexible.

❓ How do I secure my MongoDB connection?
✅ Use .env files to store your URI and use authentication with TLS for production.