Welcome to this tutorial about RESTful API using Node.js (Express.js) and MongoDB (mongoose)! We are going to learn how to install and use each component individually and then proceed to create a RESTful API.

Welcome to this tutorial about RESTful API using Node.js (Express.js) and MongoDB (mongoose)! We are going to learn how to install and use each component individually and then proceed to create a RESTful API.

MEAN Stack tutorial series:

1. AngularJS tutorial for beginners (Part I)
2. Creating RESTful APIs with NodeJS and MongoDB Tutorial (Part II) 👈 you are here
3. MEAN Stack Tutorial: MongoDB, ExpressJS, AngularJS and NodeJS (Part III)

1. What is a RESTful API?

REST stands for Representational State Transfer. It is an architecture that allows client-server communication through a uniform interface. REST is stateless, cachable and has property called idempotence. It means that the side effect of identical requests have the same side-effect as a single request.

HTTP RESTful API’s are compose of:

• HTTP methods, e.g. GET, PUT, DELETE, PATCH, POST, …
• Base URI, e.g. [http://adrianmejia.com](http://adrianmejia.com "http://adrianmejia.com")
• URL path, e.g. /blog/2014/10/01/creating-a-restful-api-tutorial-with-nodejs-and-mongodb/
• Media type, e.g. html, JSON, XML, Microformats, Atom, Images…

Here is a summary what we want to implement:

NOTE for this tutorial:

• HTTP methods, e.g. GET, PUT, DELETE, PATCH, POST, …
• Base URI, e.g. [http://adrianmejia.com](http://adrianmejia.com "http://adrianmejia.com")
• URL path, e.g. /blog/2014/10/01/creating-a-restful-api-tutorial-with-nodejs-and-mongodb/
• Media type, e.g. html, JSON, XML, Microformats, Atom, Images…

  2. Installing the MEAN Stack Backend

In this section, we are going to install the backend components of the MEAN stack: MongoDB, NodeJS and ExpressJS. If you already are familiar with them, then jump to wiring the stack. Otherwise, enjoy the ride!

2.1 Installing MongoDB

MongoDB is a document-oriented NoSQL database (Big Data ready). It stores data in JSON-like format and allows users to perform SQL-like queries against it.

You can install MongoDB following the instructions here.

If you have a Mac and brew it’s just:

brew install mongodb && mongod

In Ubuntu:

sudo apt-get -y install mongodb

After you have them installed, check version as follows:

# Mac
mongod --version
# => db version v2.6.4
# => 2014-10-01T19:07:26.649-0400 git version: nogitversion

# Ubuntu
mongod --version
# => db version v2.0.4, pdfile version 4.5
# => Wed Oct  1 23:06:54 git version: nogitversion

2.2 Installing NodeJS

The Node official definition is:

Node.js® is a JavaScript runtime built on Chrome’s V8 JavaScript engine. Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient. Node.js’ package ecosystem, npm, is the largest ecosystem of open source libraries in the world.> Node.js® is a JavaScript runtime built on Chrome’s V8 JavaScript engine. Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient. Node.js’ package ecosystem, npm, is the largest ecosystem of open source libraries in the world. In short, NodeJS allows you to run Javascript outside the browser, in this case, on the web server. NPM allows you to install/publish node packages with ease.

To install it, you can go to the NodeJS Website.

Since Node versions changes very often. You can use the NVM (Node Version Manager) on Ubuntu and Mac with:

# download NPM
curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.31.4/install.sh | bash

# load NPM
export NVM_DIR="$HOME/.nvm"
[ -s "$NVM_DIR/nvm.sh" ] && . "$NVM_DIR/nvm.sh" # This loads nvm

# Install latest stable version
nvm install stable

Check out https://github.com/creationix/nvm for more details.

Also, on Mac and brew you can do:

brew install nodejs

After you got it installed, check node version and npm (node package manager) version:

node -v
# => v6.2.2

npm -v
# => 3.9.5

2.3 nstalling ExpressJS

ExpressJS is a web application framework that runs on NodeJS. It allows you to build web applications and API endpoints. (more details on this later).

We are going to create a project folder first, and then add express as a dependency. Let’s use NPM init command to get us started.

# create project folder
mkdir todo-app

# move to the folder and initialize the project
cd todo-app
npm init .  # press enter multiple times to accept all defaults

# install express v4.14 and save it as dependency
npm install [email protected] --save

Notice that after the last command, express should be added to package.json with the version 4.14.x.

3. Using MongoDB with Mongoose

Mongoose is an NPM package that allows you to interact with MongoDB. You can install it as follows:

npm install [email protected] --save

If you followed the previous steps, you should have all you need to complete this tutorial. We are going to build an API that allow users to CRUD (Create-Read-Update-Delete) Todo tasks from database.

3.1 Mongoose CRUD

CRUD == Create-Read-Update-Delete

We are going to create, read, update and delete data from MongoDB using Mongoose/Node. First, you need to have mongodb up and running:

# run mongo daemon
mongod

Keep mongo running in a terminal window and while in the folder todoApp type node to enter the node CLI. Then:

// Load mongoose package
var mongoose = require('mongoose');

// Connect to MongoDB and create/use database called todoAppTest
mongoose.connect('mongodb://localhost/todoAppTest');

// Create a schema
var TodoSchema = new mongoose.Schema({
  name: String,
  completed: Boolean,
  note: String,
  updated_at: { type: Date, default: Date.now },
});

// Create a model based on the schema
var Todo = mongoose.model('Todo', TodoSchema);

Great! Now, let’s test that we can save and edit data.

3.2 Mongoose Create

// Create a todo in memory
var todo = new Todo({name: 'Master NodeJS', completed: false, note: 'Getting there...'});

// Save it to database
todo.save(function(err){
  if(err)
    console.log(err);
  else
    console.log(todo);
});

If you take a look to Mongo you will notice that we just created an entry. You can easily visualize data using Robomongo:

You can also build the object and save it in one step using create:

Todo.create({name: 'Create something with Mongoose', completed: true, note: 'this is one'}, function(err, todo){
  if(err) console.log(err);
  else console.log(todo);
});

3.3 Mongoose Read and Query

So far we have been able to save data, now we are going explore how to query the information. There are multiple options for reading/querying data:

• HTTP methods, e.g. GET, PUT, DELETE, PATCH, POST, …
• Base URI, e.g. [http://adrianmejia.com](http://adrianmejia.com "http://adrianmejia.com")
• URL path, e.g. /blog/2014/10/01/creating-a-restful-api-tutorial-with-nodejs-and-mongodb/
• Media type, e.g. html, JSON, XML, Microformats, Atom, Images…

Some examples:

// Find all data in the Todo collection
Todo.find(function (err, todos) {
  if (err) return console.error(err);
  console.log(todos)
});

The result is something like this:

[ { _id: 57a6116427f107adef36c2f2,
    name: 'Master NodeJS',
    completed: false,
    note: 'Getting there...',
    __v: 0,
    updated_at: 2016-08-06T16:33:40.606Z },
  { _id: 57a6142127f107adef36c2f3,
    name: 'Create something with Mongoose',
    completed: true,
    note: 'this is one',
    __v: 0,
    updated_at: 2016-08-06T16:45:21.143Z } ]

You can also add queries

// callback function to avoid duplicating it all over
var callback = function (err, data) {
  if (err) { return console.error(err); }
  else { console.log(data); }
}

// Get ONLY completed tasks
Todo.find({completed: true }, callback);

// Get all tasks ending with `JS`
Todo.find({name: /JS$/ }, callback);

You can chain multiple queries, e.g.:

var oneYearAgo = new Date();
oneYearAgo.setYear(oneYearAgo.getFullYear() - 1);

// Get all tasks staring with `Master`, completed
Todo.find({name: /^Master/, completed: true }, callback);

// Get all tasks staring with `Master`, not completed and created from year ago to now...
Todo.find({name: /^Master/, completed: false }).where('updated_at').gt(oneYearAgo).exec(callback);

MongoDB query language is very powerful. We can combine regular expressions, date comparison and more!

3.4 Mongoose Update

Moving on, we are now going to explore how to update data.

Each model has an update method which accepts multiple updates (for batch updates, because it doesn’t return an array with data).

• HTTP methods, e.g. GET, PUT, DELETE, PATCH, POST, …
• Base URI, e.g. [http://adrianmejia.com](http://adrianmejia.com "http://adrianmejia.com")
• URL path, e.g. /blog/2014/10/01/creating-a-restful-api-tutorial-with-nodejs-and-mongodb/
• Media type, e.g. html, JSON, XML, Microformats, Atom, Images…

Alternatively, the method findOneAndUpdate could be used to update just one and return an object.

// Model.update(conditions, update, [options], [callback])
// update `multi`ple tasks from complete false to true

Todo.update({ name: /master/i }, { completed: true }, { multi: true }, callback);

//Model.findOneAndUpdate([conditions], [update], [options], [callback])
Todo.findOneAndUpdate({name: /JS$/ }, {completed: false}, callback);

As you might noticed the batch updates (multi: true) doesn’t show the data, rather shows the number of fields that were modified.

{ ok: 1, nModified: 1, n: 1 }

Here is what they mean:

• HTTP methods, e.g. GET, PUT, DELETE, PATCH, POST, …
• Base URI, e.g. [http://adrianmejia.com](http://adrianmejia.com "http://adrianmejia.com")
• URL path, e.g. /blog/2014/10/01/creating-a-restful-api-tutorial-with-nodejs-and-mongodb/
• Media type, e.g. html, JSON, XML, Microformats, Atom, Images…

  3.5 Mongoose Delete

update and remove mongoose API are identical, the only difference it is that no elements are returned. Try it on your own ;)

• HTTP methods, e.g. GET, PUT, DELETE, PATCH, POST, …
• Base URI, e.g. [http://adrianmejia.com](http://adrianmejia.com "http://adrianmejia.com")
• URL path, e.g. /blog/2014/10/01/creating-a-restful-api-tutorial-with-nodejs-and-mongodb/
• Media type, e.g. html, JSON, XML, Microformats, Atom, Images…

  4. ExpressJS and Middlewares

ExpressJS is a complete web framework solution. It has HTML template solutions (jade, ejs, handlebars, hogan.js) and CSS precompilers (less, stylus, compass). Through middlewares layers, it handles: cookies, sessions, caching, CSRF, compression and many more.

Middlewares are pluggable processors that runs on each request made to the server. You can have any number of middlewares that will process the request one by one in a serial fashion. Some middlewares might alter the request input. Others, might create log outputs, add data and pass it to the next() middleware in the chain.

We can use the middlewares using app.use. That will apply for all request. If you want to be more specific, you can use app.verb. For instance: app.get, app.delete, app.post, app.update, …

Let’s give some examples of middlewares to drive the point home.

Say you want to log the IP of the client on each request:

app.use(function (req, res, next) {
  var ip = req.headers['x-forwarded-for'] || req.connection.remoteAddress;
  console.log('Client IP:', ip);
  next();
});

Notice that each middleware has 3 parameters:

• HTTP methods, e.g. GET, PUT, DELETE, PATCH, POST, …
• Base URI, e.g. [http://adrianmejia.com](http://adrianmejia.com "http://adrianmejia.com")
• URL path, e.g. /blog/2014/10/01/creating-a-restful-api-tutorial-with-nodejs-and-mongodb/
• Media type, e.g. html, JSON, XML, Microformats, Atom, Images…

You can also specify a path that you want the middleware to activate on.

Middleware mounted on "/todos/:id" and log the request method

app.use('/todos/:id', function (req, res, next) {
  console.log('Request Type:', req.method);
  next();
});

And finally you can use app.get to catch GET requests with matching routes, reply the request with a response.send and end the middleware chain. Let’s use what we learned on mongoose read to reply with the user’s data that matches the id.

Middleware mounted on "/todos/:id" and returns

app.get('/todos/:id', function (req, res, next) {
  Todo.findById(req.params.id, function(err, todo){
    if(err) res.send(err);
    res.json(todo);
  });
});

Notice that all previous middlewares called next() except this last one, because it sends a response (in JSON) to the client with the requested todo data.

Hopefully, you don’t have to develop a bunch of middlewares besides routes, since ExpressJS has a bunch of middlewares available.

4.1 Default Express 4.0 middlewares

• HTTP methods, e.g. GET, PUT, DELETE, PATCH, POST, …
• Base URI, e.g. [http://adrianmejia.com](http://adrianmejia.com "http://adrianmejia.com")
• URL path, e.g. /blog/2014/10/01/creating-a-restful-api-tutorial-with-nodejs-and-mongodb/
• Media type, e.g. html, JSON, XML, Microformats, Atom, Images…

  4.2 Other ExpressJS Middlewares

The following middlewares are not added by default, but it’s nice to know they exist at least:

• HTTP methods, e.g. GET, PUT, DELETE, PATCH, POST, …
• Base URI, e.g. [http://adrianmejia.com](http://adrianmejia.com "http://adrianmejia.com")
• URL path, e.g. /blog/2014/10/01/creating-a-restful-api-tutorial-with-nodejs-and-mongodb/
• Media type, e.g. html, JSON, XML, Microformats, Atom, Images…

  5. Wiring up the MEAN Stack

In the next sections, we are going to put together everything that we learn from and build an API. They can be consume by browsers, mobile apps and even other servers.

5.1 Bootstrapping ExpressJS

After a detour in the land of Node, MongoDB, Mongoose, and middlewares, we are back to our express todoApp. This time to create the routes and finalize our RESTful API.

Express has a separate package called express-generator, which can help us to get started with out API.

# install it globally using -g
npm install express-generator -g

# create todo-app API with EJS views (instead the default Jade)
express todo-api -e

#   create : todo-api
#   create : todo-api/package.json
#   create : todo-api/app.js
#   create : todo-api/public
#   create : todo-api/public/javascripts
#   create : todo-api/routes
#   create : todo-api/routes/index.js
#   create : todo-api/routes/users.js
#   create : todo-api/public/stylesheets
#   create : todo-api/public/stylesheets/style.css
#   create : todo-api/views
#   create : todo-api/views/index.ejs
#   create : todo-api/views/layout.ejs
#   create : todo-api/views/error.ejs
#   create : todo-api/public/images
#   create : todo-api/bin
#   create : todo-api/bin/www
#
#   install dependencies:
#     $ cd todo-api && npm install
#
#   run the app on Linux/Mac:
#     $ DEBUG=todo-app:* npm start
#
#   run the app on Windows:
#     $ SET DEBUG=todo-api:* & npm start

This will create a new folder called todo-api. Let’s go ahead and install the dependencies and run the app:

# install dependencies
cd todo-api && npm install

# run the app on Linux/Mac
PORT=4000 npm start

# run the app on Windows
SET PORT=4000 & npm start

Use your browser to go to http://0.0.0.0:4000, and you should see a message “Welcome to Express”

5.2 Connect ExpressJS to MongoDB

In this section we are going to access MongoDB using our newly created express app. Hopefully, you have installed MongoDB in the setup section, and you can start it by typing (if you haven’t yet):

mongod

Install the MongoDB driver for NodeJS called mongoose:

npm install mongoose --save

Notice --save. It will add it to the todo-api/package.json

Next, you need to require mongoose in the todo-api/app.js

// load mongoose package
var mongoose = require('mongoose');

// Use native Node promises
mongoose.Promise = global.Promise;

// connect to MongoDB
mongoose.connect('mongodb://localhost/todo-api')
  .then(() =>  console.log('connection succesful'))
  .catch((err) => console.error(err));

Now, When you run npm start or ./bin/www, you will notice the message connection successful. Great!

You can find the repository here and the diff code at this point: diff

5.3 Creating the Todo model with Mongoose

It’s show time! All the above was setup and preparation for this moment. Let bring the API to life.

Create a models directory and a Todo.js model:

mkdir models
touch models/Todo.js

In the models/Todo.js:

var mongoose = require('mongoose');

var TodoSchema = new mongoose.Schema({
  name: String,
  completed: Boolean,
  note: String,
  updated_at: { type: Date, default: Date.now },
});

module.exports = mongoose.model('Todo', TodoSchema);

diff

What’s going on up there? Isn’t MongoDB suppose to be schemaless? Well, it is schemaless and very flexible indeed. However, very often we want bring sanity to our API/WebApp through validations and enforcing a schema to keep a consistent structure. Mongoose does that for us, which is nice.

You can use the following types:

• HTTP methods, e.g. GET, PUT, DELETE, PATCH, POST, …
• Base URI, e.g. [http://adrianmejia.com](http://adrianmejia.com "http://adrianmejia.com")
• URL path, e.g. /blog/2014/10/01/creating-a-restful-api-tutorial-with-nodejs-and-mongodb/
• Media type, e.g. html, JSON, XML, Microformats, Atom, Images…

  6. API clients (Browser, Postman and curl)

I know you have not created any route yet. However, in the next sections you will. These are just three ways to retrieve, change and delete data from your future API.

6.1 Curl

# Create task
curl -XPOST http://localhost:3000/todos -d 'name=Master%20Routes&completed=false&note=soon...'

# List tasks
curl -XGET http://localhost:3000/todos

6.2 Browser and Postman

If you open your browser and type localhost:3000/todos you will see all the tasks (when you implement it). However, you cannot do post commands by default. For further testing let’s use a Chrome plugin called Postman. It allows you to use all the HTTP VERBS easily and check x-www-form-urlencoded for adding parameters.

Node.js® is a JavaScript runtime built on Chrome’s V8 JavaScript engine. Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient. Node.js’ package ecosystem, npm, is the largest ecosystem of open source libraries in the world.## 6.3 Websites and Mobile Apps

Probably these are the main consumers of APIs. You can interact with RESTful APIs using jQuery’s $ajax and its wrappers, BackboneJS’s Collections/models, AngularJS’s $http or $resource, among many other libraries/frameworks and mobile clients.

In the end, we are going to explain how to use AngularJS to interact with this API.

7. ExpressJS Routes

To sum up we want to achieve the following:

Let’s setup the routes

mv routes/users.js routes/todos.js

In app.js add new todos route, or just replace ./routes/users for ./routes/todos

var todos = require('./routes/todos');
app.use('/todos', todos);

All set! Now, let’s go back and edit our routes/todos.js.

7.1 List: GET /todos

Remember mongoose query api? Here’s how to use it in this context:

var express = require('express');
var router = express.Router();

var mongoose = require('mongoose');
var Todo = require('../models/Todo.js');

/* GET /todos listing. */
router.get('/', function(req, res, next) {
  Todo.find(function (err, todos) {
    if (err) return next(err);
    res.json(todos);
  });
});

module.exports = router;

Harvest time! We don’t have any task in database but at least we verify it is working:

# Start database
mongod

# Start Webserver (in other terminal tab)
npm start

# Test API (in other terminal tab)
curl localhost:3000/todos
# => []%

diff

If it returns an empty array [] you are all set. If you get errors, try going back and making sure you didn’t forget anything, or you can comment at the end of the post for help.

7.2 Create: POST /todos

Back in routes/todos.js, we are going to add the ability to create using mongoose create. Can you make it work before looking at the next example?

/* POST /todos */
router.post('/', function(req, res, next) {
  Todo.create(req.body, function (err, post) {
    if (err) return next(err);
    res.json(post);
  });
});

diff

A few things:

• HTTP methods, e.g. GET, PUT, DELETE, PATCH, POST, …
• Base URI, e.g. [http://adrianmejia.com](http://adrianmejia.com "http://adrianmejia.com")
• URL path, e.g. /blog/2014/10/01/creating-a-restful-api-tutorial-with-nodejs-and-mongodb/
• Media type, e.g. html, JSON, XML, Microformats, Atom, Images…

Everytime you change a file you have to stop and start the web server. Let’s fix that using nodemon to refresh automatically:

# install nodemon globally
npm install nodemon -g

# Run web server with nodemon
nodemon

7.3 Show: GET /todos/:id

This is a snap with [Todo.findById](https://codequs.com/p/rytO0EuH4/creating-restful-apis-with-nodejs-and-mongodb-tutorial#mongoose-read-and-query "Todo.findById") and req.params. Notice that params matches the placeholder name we set while defining the route. :id in this case.

/* GET /todos/id */
router.get('/:id', function(req, res, next) {
  Todo.findById(req.params.id, function (err, post) {
    if (err) return next(err);
    res.json(post);
  });
});

diff

Let’s test what we have so far!

# Start Web Server on port 4000 (default is 3000)
PORT=4000 nodemon

# Create a todo using the API
curl -XPOST http://localhost:4000/todos -d 'name=Master%20Routes&completed=false&note=soon...'
# => {"__v":0,"name":"Master Routes","completed":false,"note":"soon...","_id":"57a655997d2241695585ecf8"}%

# Get todo by ID (use the _id from the previous request, in my case "57a655997d2241695585ecf8")
curl -XGET http://localhost:4000/todos/57a655997d2241695585ecf8
{"_id":"57a655997d2241695585ecf8","name":"Master Routes","completed":false,"note":"soon...","__v":0}%

# Get all elements (notice it is an array)
curl -XGET http://localhost:4000/todos
[{"_id":"57a655997d2241695585ecf8","name":"Master Routes","completed":false,"note":"soon...","__v":0}]%

7.4 Update: PUT /todos/:id

Back in routes/todos.js, we are going to update tasks. This one you can do without looking at the example below, review findByIdAndUpdate and give it a try!

/* PUT /todos/:id */
router.put('/:id', function(req, res, next) {
  Todo.findByIdAndUpdate(req.params.id, req.body, function (err, post) {
    if (err) return next(err);
    res.json(post);
  });
});

diff

# Use the ID from the todo, in my case 57a655997d2241695585ecf8
curl -XPUT http://localhost:4000/todos/57a655997d2241695585ecf8 -d "note=hola"
# => {"_id":"57a655997d2241695585ecf8","name":"Master Routes","completed":true,"note":"hola","__v":0}%

7.5 Destroy: DELETE /todos/:id

Finally, the last one! Almost identical to update, use [findByIdAndRemove](https://codequs.com/p/rytO0EuH4/creating-restful-apis-with-nodejs-and-mongodb-tutorial#mongoose-delete "findByIdAndRemove").

/* DELETE /todos/:id */
router.delete('/:id', function(req, res, next) {
  Todo.findByIdAndRemove(req.params.id, req.body, function (err, post) {
    if (err) return next(err);
    res.json(post);
  });
});

diff

Is it working? Cool, you are done then! Is NOT working? take a look at the full repository.

In this tutorial, we build A REST API With MongoDB, Mongoose, And Node.js .... Mongoose is Nodejs package for modeling Mongodb.

How to Build a RESTful API in Node.js, Express.js and MongoDB (Mongoose). Learn to create your first RESTful API in NodeJS, ExpressJS, and MongoDB (mongoose). We cover the MVC pattern, CRUD, Routes, Error Handling, ES6, Promises, GET, POST, DELETE in under 50 minutes. Learn to build a REST API to create,modify and delete users in a database. Build a simple API using ExpressJs and MongoDb with CRUD functions for Contacts.

Node.js, Express.js, Mongoose.js, and MongoDB is a great combination for building easy and fast REST API. You will see how fast that combination than other existing frameworks because of Node.js is a packaged compilation of Google’s V8 JavaScript engine and it works on non-blocking and event-driven I/O. Express.js is a Javascript web server that has a complete function of web development including REST API.