CRUD operations using NodeJS + Express + MongoDB

I'll start this tutorial by keeping in mind that you already know the basics of NodeJS.
If you are not installed NodeJS on your machine, please go ahead and install the latest version first. The following tutorial shows you how to install on Ubuntu machines

https://onecompiler.com/posts/3sqr8r5j6/how-to-install-latest-versions-of-nodejs-and-npm-in-ubuntu-16-04

Project Setup

Once you installed NodeJS, open terminal and create a folder with name nodejs-mongodb-crud and move to that folder by running following series of commands

mkdir nodejs-mongodb-crud
cd nodejs-mongodb-crud

Now create a new node project by running the following command.

npm init --yes

This creates you a package.json file.
Now start adding required dependencies by running following command

npm install express body-parser mongodb co --save 

Now if you look at your packages.json file, it should look like following

{
  "name": "nodejs-mongodb-crud",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "body-parser": "^1.18.2",
    "co": "^4.6.0",
    "express": "^4.16.2",
    "mongodb": "^3.0.3"
  }
}

Now you are ready with the setup, lets start writing our index.js and add the basic CRUD routes.
Create the index.js file and put the following content

index.js

var express = require('express');
var bodyParser = require('body-parser');
var co = require('co')

var app = express();

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

// Express Configurations
app.use(bodyParser.urlencoded({
  limit: "5mb",
  extended: false
}));
app.use(bodyParser.json({limit: "5mb"}));
app.set('port', (process.env.PORT || 8080));


// Mongo
db = {};
var mongoDbUri = 'mongodb://localhost:27017/nodejs-mongodb-crud-db'
var settings = {
      reconnectTries : Number.MAX_VALUE,
      autoReconnect : true
};
MongoClient.connect(mongoDbUri, settings, function(err, dbref) {
  if (!err) {
    db = dbref.db('nodejs-mongodb-crud-db');
    addRouts();
    console.log("Mongodb connected");
  }
});

app.post('/user', function(req, res){
  co(function*() {
    yield db.collection('users').save(req.body)
    res.send('Created')
  }).catch(function(err) {
    console.log(err.stack)
    res.status(500).send(err)
  })
})

// read
app.get('/user/:id', function(req, res){
  var id = req.params.id
  co(function*() {
    var userObj = yield db.collection('users').findOne({_id:id})
    res.send(userObj)
  }).catch(function(err) {
    console.log(err.stack)
    res.status(500).send(err)
  });
});

// update
app.put('/user', function(req, res){
  co(function*() {
    yield db.collection('users').save(req.body)
    res.send('Updated')
  }).catch(function(err) {
    console.log(err.stack)
    res.status(500).send(err)
  })
})

// delete
app.delete('/user/:id', function(req, res){
  var id = req.params.id
  co(function*() {
    yield db.collection('users').deleteOne({_id:id});
    res.send('Deleted Successfully')
  }).catch(function(err) {
    console.log(err.stack)
    res.status(500).send(err)
  })
})

// Start App
app.listen(app.get('port'), function() {
  console.log('Node app is running on port: ', app.get('port'));
});

Starting Node Application

Now start the application by running following command

node index.js

After successful start you should see logs like below

$ node index.js
Node app is running on port:  8080
Mongodb connected

Testing CRUD operations

Now lets start testing the CRUD operations with curl commands

Create

curl -X POST \
  http://localhost:8080/user \
  -H 'content-type: application/json' \
  -d '{
    "_id" : "E-001",
    "name" : "Test Name 1",
    "age" : 20,
    "email" : "[email protected]"
}'

Read

curl -X GET \
  http://localhost:8080/user/E-001

Update

curl -X PUT \
  http://localhost:8080/user \
  -H 'content-type: application/json' \
  -d '{
    "_id" : "E-001",
    "name" : "Test Name 2",
    "age" : 22,
    "email" : "[email protected]"
}'

Delete

curl -X DELETE \
  http://localhost:8080/user/E-001