Node.js MongoDB

Node.js can be used in database applications.

One of the most popular NoSQL database is MongoDB.

MongoDB

To be able to experiment with the code examples, you will need access to a MongoDB database.

You can download a free MongoDB database at https://www.mongodb.com.

Or get started right away with a MongoDB cloud service at https://www.mongodb.com/cloud/atlas.

Install MongoDB Driver

Let us try to access a MongoDB database with Node.js.

To download and install the official MongoDB driver, open the Command Terminal and execute the following:

Download and install mongodb package:

C:\Users\Your Name> npm install mongodb

Now you have downloaded and installed a mongodb database driver.

Node.js can use this module to manipulate MongoDB databases:

var mongo = require('mongodb');

Node.js MongoDB Create Database

Creating a Database

To create a database in MongoDB, start by creating a MongoClient object, then specify a connection URL with the correct ip address and the name of the database you want to create.

MongoDB will create the database if it does not exist, and make a connection to it.

Example

Create a database called "mydb":

var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/mydb";

MongoClient.connect(url, function(err, db) {
  if (err) throw err;
  console.log("Database created!");
  db.close();
});

Save the code above in a file called "demo_create_mongo_db.js" and run the file:

Run "demo_create_mongo_db.js"

C:\Users\Your Name>node demo_create_mongo_db.js

Which will give you this result:

Database created!

Important: In MongoDB, a database is not created until it gets content!

MongoDB waits until you have created a collection (table), with at least one document (record) before it actually creates the database (and collection).

Node.js MongoDB Create Collection

A collection in MongoDB is the same as a table in MySQL

Creating a Collection

To create a collection in MongoDB, use the createCollection() method:

Example

Create a collection called "customers":

var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/";

MongoClient.connect(url, function(err, db) {
  if (err) throw err;
  var dbo = db.db("mydb");
  dbo.createCollection("customers", function(err, res) {
    if (err) throw err;
    console.log("Collection created!");
    db.close();
  });
});

Save the code above in a file called "demo_mongodb_createcollection.js" and run the file:

Run "demo_mongodb_createcollection.js"

C:\Users\Your Name>node demo_mongodb_createcollection.js

Which will give you this result:

Collection created!

Important: In MongoDB, a collection is not created until it gets content!

MongoDB waits until you have inserted a document before it actually creates the collection.