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Create a CRUD Application in Express JS and MongoDB

  • By Preethima K
  • June 26, 2020
  • 1245 Views

In this blog, we will be learning how to create simple crud APIs in Express JS ( Node JS Framework ).
The Mean stack is used to describe development using MongoDB, Express.js, Angular.jS, and Node.js. Now, I will show you how to use Express.js, Node.js, and MongoDB.js. We will be creating a simple Node application that will allow users to input data they want to store in a MongoDB database, also showing all other data entered.

Install using Node, Express, MongoDB 

Express

Express.js is a web application framework. It simplifies the server creation process that is already available in Node. Node allows you to use JavaScript as your server-side language.
We need to install express via npm

npm install express --save

MongoDB 

MongoDB is an open-source database. Mongoose is a client API for node.js, making it easy to access our database from our Express application.
We need to install MongoDB via npm.

npm install mongodb --save

Create a project in Express 

 For creating a project, we run the below command in the command prompt where you want to create.

npm init

Project Structure

MongoCrud- Package name
controller
– product.controller.js
Models
– product.model.js
– routes
– product.route.js
– node_modules
– app.js
– package.json

Create a Database Connectivity File

Here we can create a file in mongoose schemas and MongoDB connection. You should connect to MongoDB through the Mongo client’s connect method.

const MongoClient = require('mongodb').MongoClient
MongoClient.connect('mongodb-connection-string', (err, client) => {
})

app.js

const express = require('express');
const bodyParser = require('body-parser');
const mongoose = require('mongoose');
mongoose.connect("mongodb://localhost:27017/testdb", {
keepAlive: true,
keepAliveInitialDelay: 300000,
socketTimeoutMS: 2000000,
useNewUrlParser: true,
useUnifiedTopology: true,
useCreateIndex: true,
}).then(data=>console.log('db connected')).catch(err=>console.log('db error', err));
const product = require('./routes/product.route');
const app = express();
app.use(express.json());
app.use('/products', product);
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));
let port = 3000;
app.listen(port, () => {
console.log('Running on port numner ' + port);
});

Create a Model Schema

Everything in Mongoose starts with a Schema. Each schema maps to a MongoDB collection and defines the type of the documents within that collection.
product.model.js

const mongoose = require('mongoose');
const Schema = mongoose.Schema;
require('mongoose-type-email');
let studentSchema = new Schema({
id: { type: Number, required: true, max: 100 },
firstName: { type: String, required: true, max: 100 },
lastName: { type: String, required: true, max: 100 },
email: { type: mongoose.SchemaTypes.Email, required: true },
amount: [{ type: Number, required: true, max: 100 }]
});
// Export the model
module.exports = mongoose.model("students", studentSchema, "students");

Create a Controller 

We created CRUD for communicating with the server. Now we will apply the real logic to the route and controller.
Create a  new student (POST request)

const Student = require('../models/product.model');
//Simple Testing
exports.test = function (req, res) {
 res.send('Hi guys!');
};
exports.student_create = function (req, res, next) {
 var product = [{
   id: req.body.id,
   firstName: req.body.firstName,
   lastName: req.body.lastName,
   email: req.body.email,
 }]
 Student.create(product, ((err, result) => {
   console.log('result', result);
   if (!err) {
     res.send({
       msg: "Data inserted successfully"
       data: result
    })
     return;
   }

In the route, we don’t have to pass anything, Here we can upload the route file.
Product.route.js

const express = require('express');
const router = express.Router();
// call for controller
const product_controller = require('../controller/product.controller');
// test url
router.get('/test', product_controller.test);
router.post('/create', product_controller.student_create);
module.exports = router;
   res.send({
     msg: "error",
   })
 }));
}

Get all student (GET request)

 exports.get_Student = function (req, res, next) {
  Student.find({})
   .then((response) => {
     console.log("response", response);
     res.json({
       data: response,
       msg: 'Getting all the student data'
      });
   })
   .catch((err) => {
     res.send('error has occured', err);
   })
};

we will import Controller and apply getstudent method.

router.get('/allStudents', product_controller.get_Student);

Update a single student (PUT method)

Remember that, without {new: true}, the updated document will not be returned.

exports.update_Student = function (req, res) {
 Student.findOneAndUpdate(req.params._id, {
   id: req.body.id,
   firstName: req.body.firstName,
   lastName: req.body.lastName,
   email: req.body.email,
 }, { new: true, useFindAndModify: false }, function (err, result) {
   if (err) {
     console.log('err', err);
     res.send('error updating student');
   } else {
     console.log(result);
     res.status(200).send({
       data: result,
       msg: 'data updated successfully'
     });
   }
 });
};

In the routes,

router.put('/Student/:id', product_controller.update_Student);

Delete a single contact (DELETE method)

exports.delete_Student = function(req, res, next) {
 Student.findByIdAndRemove({_id: req.params.id}, function(err, hero) {
     if(err) {
         res.json({
             error : err
         })
     }
     res.json({
         message : "Student deleted successfully"
     })
 })
}

In the routes,

router.delete('/delete/:id', product_controller.delete_Student);

API Calls

Below are the all screenshots of all APIs call, which having REST APIs and results of these APIs.

Create API

Get API

Update API

Delete API


If you’re looking for highly experienced and talented Node.js developers, you can get in touch with technical advisors to find a developer at your affordable price. At Agira Technologies, we have flexible models that can help your development in better ways possible.

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