Node.js MongoDB Create Collection

In MongoDB, a collection is a grouping of documents, similar to a table in relational databases. Using Node.js, you can create collections programmatically. This guide explains how to create a collection in MongoDB with Node.js.

 

Key Features of Collection Creation

1. Flexible Schema: MongoDB collections can store documents with varying structures.
2. On-Demand Creation: Collections are automatically created when data is added if they don’t exist.
3. Explicit Creation: Use the createCollection method for specific configurations.

 

Step 1 Prerequisites

Ensure you have MongoDB installed and the mongodb package installed in your Node.js project.

npm install mongodb

Step 2 Connect to MongoDB

Connect to the MongoDB server using the MongoClient class.

Example Code

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

// Connection URL and Database Name
const url = 'mongodb://127.0.0.1:27017';
const dbName = 'mydatabase';

async function connectToDatabase() {
  const client = new MongoClient(url);

  try {
    // Connect to the MongoDB server
    await client.connect();
    console.log('Connected to MongoDB');

    // Reference the database
    const db = client.db(dbName);
    return db;
  } catch (error) {
    console.error('Connection failed:', error);
  }
}

connectToDatabase();

Step 3 Create a Collection

To explicitly create a collection, use the createCollection method.

Example Code

async function createCollection() {
  const client = new MongoClient(url);

  try {
    await client.connect();
    const db = client.db(dbName);

    // Create a new collection
    const collectionName = 'mycollection';
    await db.createCollection(collectionName);
    console.log(`Collection created: ${collectionName}`);
  } finally {
    // Close the connection
    await client.close();
  }
}

createCollection().catch(console.error);

Output:

Collection created: mycollection

Step 4 Verify the Collection

• Start the MongoDB shell or connect using a GUI like MongoDB Compass.
• Switch to your database:

use mydatabase

• View the collections:

show collections

Step 5 Insert Data into the Collection

You can also add documents to the collection to verify its existence.

Example Code

async function insertData() {
  const client = new MongoClient(url);

  try {
    await client.connect();
    const db = client.db(dbName);
    const collection = db.collection('mycollection');

    // Insert a document
    const result = await collection.insertOne({ name: 'Alice', age: 30 });
    console.log('Document inserted:', result.insertedId);
  } finally {
    await client.close();
  }
}

insertData().catch(console.error);

Output:

Document inserted: 61b0fa1e4a6c1e8b76a7c2d3

 

Summary

In MongoDB, collections can be created explicitly using the createCollection method or dynamically by inserting data. This guide demonstrated connecting to MongoDB, creating a collection, and verifying its existence. By following these steps, you can efficiently manage collections in your Node.js applications.