Connecting to a MongoDB database using Node.js

Before your Node.js application can do anything with a MongoDB instance, it must connect to it over the network.

How to do it...

The Node.js drivers for MongoDB contain all of the necessary network code to establish and break connections with MongoDB running on your local or remote machine.

You need to include a reference to the native driver in your code and specify the URL of the database to connect to.

Here's a simple example that connects to the database and promptly disconnects:

var mongo = require('mongodb').MongoClient;

var url = 'mongodb://localhost:27017/test';

mongo.connect(url, function(error, db) {
  console.log("mongo.connect returned " + error);
  db.close();
});

Let's break this down line by line.

How it works…

The first line includes the native driver implementation for Mongo in your Node.js application, and extracts a reference to the MongoClient object it defines. This object contains the basic interface you need to interact with...