Node.js Connect to MongoDB

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Node.js Connect to MongoDB

Node.js Connect to MongoDB

Node.js Connect to MongoDB – In this Node.js Tutorial, we shall learn to connect to MongoDB from Node.js Application.

Prerequisites

Make sure MongoDB is installed. If not, install MongoDB.

Step by step guide

To connect to MongoDB from Node.js Application, following is a step by step guide.

Start MongoDB service. Run the following command to start MongoDB Service

sudo service mongod start

Install mongodb package using npm (if not installed already).

arjun@nodejs:~/workspace/nodejs/mongodb$ npm install mongodb

npm WARN saveError ENOENT: no such file or directory, open '/home/arjun/workspace/nodejs/package.json'

npm WARN enoent ENOENT: no such file or directory, open '/home/arjun/workspace/nodejs/package.json'

npm WARN nodejs No description

npm WARN nodejs No repository field.

npm WARN nodejs No README data

npm WARN nodejs No license field.

+ mongodb@2.2.33

added 9 packages in 9.416s

Prepare the url. A simple hack to know the base url of MongoDB Service is to Open a Terminal and run Mongo Shell.

arjun@nodejs:~$ mongo

MongoDB shell version v3.4.9

connecting to: mongodb://127.0.0.1:27017

MongoDB server version: 3.4.9

Server has startup warnings:

2017-10-29T18:15:36.110+0530 I STORAGE [initandlisten]

While the Mongo Shell starts up, it echoes back the base url of MongoDB.

mongodb://127.0.0.1:27017

With the help of mongodb package, create a MongoClient and connect to the url.

Example Program – Node.js Connect to MongoDB

Following is an Example Node.js program to make a Node.js MongoDB Connection.

// URL at which MongoDB service is running

var url = "mongodb://localhost:27017";

// A Client to MongoDB

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

// Make a connection to MongoDB Service

MongoClient.connect(url, function(err, db) {

if (err) throw err;

console.log("Connected to MongoDB!");

db.close();

});

arjun@java:~/workspace/nodejs/mongodb$ node node-js-mongodb-connection.js

Connected to MongoDB!

Conclusion :

In this Node.js MongoDB – Node.js Connect to MongoDB, we have learnt to find the url of the MongoDB Service and connect to the service from Node.js using MongoClient’s connect method, demonstrated by an Example program.

Node.js Connect to MongoDB – Example