How to connect Node.js with MongoDB and read data

To connect Node.js with MongoDB and read data, follow these steps:

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Step 1: Install Dependencies

Make sure you have Node.js installed, then install the MongoDB Node.js driver using npm:

npm init -y
npm install mongodb

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Step 2: Create a Connection to MongoDB

Create a file index.js and write the following code:

const { MongoClient } = require("mongodb");

// Connection URL
const uri = "mongodb://localhost:27017"; // Change to your MongoDB URL
const client = new MongoClient(uri);

// Database and Collection Name
const dbName = "testDB";  // Change to your database name
const collectionName = "users";  // Change to your collection name

async function readData() {
    try {
        // Connect to MongoDB
        await client.connect();
        console.log("Connected to MongoDB");

        const db = client.db(dbName);
        const collection = db.collection(collectionName);

        // Read Data
        const result = await collection.find({}).toArray();
        console.log("Data:", result);
    } catch (err) {
        console.error("Error:", err);
    } finally {
        // Close connection
        await client.close();
    }
}

// Call the function
readData();

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Step 3: Run the Script

Run the file using:

node index.js

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Explanation

1. MongoClient is used to connect to MongoDB.
2. client.connect() establishes the connection.
3. db.collection().find({}).toArray() fetches all documents from the collection.
4. await client.close() closes the connection after execution.

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Additional Tips

• If you’re using MongoDB Atlas (Cloud), replace "mongodb://localhost:27017" with your MongoDB Atlas connection string.
• To filter data, modify find({}), e.g., find({ age: { $gt: 25 } }) to get users older than 25.