Node.js - MongoDB Create Collection

A MongoDB database is made up of one or more Collections. A Collection is a group of document objects. Once a database is created on the MongoDB server (a standalone server or a on a shared cluster in MongoDB Atlas), you can then create Collections in it. The mongodb driver for Node.js has a cerateCollection() method, that returns a Collection object.

Collection in MongoDB is similar to the table in a relational database. However, it doesn't have a predefined schema. Each document in a collection may consist of variable number of k-v pairs not necessarily with same keys in each document.

To create a collection, get the database object from the database connection and call the createCollection() method.

db.createCollection(name: string, options)

The name of the collection to create is passed as the argument. The method returns a Promise. Collection namespace validation is performed server-side.

const dbobj = await client.db(dbname);
const collection = await dbobj.createCollection("MyCollection");

Note that the collection is implicitly created when you insert a document in it even if it is not created before insertion.

const result = await client.db("mydatabase").collection("newcollection").insertOne({k1:v1, k2:v2});

Example

The following Node.js code creates a Collection named MyCollection in a MongoDB database named mydatabase.

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

async function main(){

   const uri = "mongodb://localhost:27017/";

   const client = new MongoClient(uri);

   try {
      // Connect to the MongoDB cluster
      await client.connect();
        
      await newcollection(client, "mydatabase");
   } finally {
      // Close the connection to the MongoDB cluster
      await client.close();
   }
}

main().catch(console.error);


async function newcollection (client, dbname){
   const dbobj = await client.db(dbname);
   const collection = await dbobj.createCollection("MyCollection");
   console.log("Collection created");
   console.log(collection);
}

The MongoDB Compass shows that the MyCollection is created in mydatabase.

You can also verify the same in MongoDB shell.

> use mydatabase
< switched to db mydatabase
> show collections
< MyCollection