Create Nodejs Server for HTTP requests

a) Install nodejs

b) Prepare for Node js server,

Create base structure

mkdir myappnode

cd myappnode

npm init       (accept all defaults, creates package.json)

npm install --save express body-parser

Create route base structure

mkdir app

cd app

mkdir routes

cd routes

Add HTTP GET method support

vi myapp_routes.js
module.exports = function(app, db) {

  app.get('/myapp', (req, res) => {

    res.send('Hello from myapp, GET method')

  });

};

Create new index.js (/app/routes/index.js)

const noteRoutes = require('./myapp_routes');

module.exports = function(app, db) {

  noteRoutes(app, db);

  

};

Update server.js 

cd ../..
vi server.js
const express        = require('express');

const app            = express();

const port = 9000;

require('./app/routes')(app, {});

app.listen(port, () => {

  console.log('Server running on' + port);

});

Start server.js 

node server.js

Test using webbrowser 

http://localhost:9000/myapp

Output : Hello from myapp, GET method

ADDITIONAL CODE TO CONNECT TO mysql

1. Install mysql module

npm install --save mysql

2. Modify 

vi app/routes/myapp_routes.js 

module.exports = function(app, db) {

  app.get('/myapp', (req, res) => {

    res.send('Hello from myapp, GET method')

  });

};

var mysql = require('mysql');

var con = mysql.createConnection({

  host: "localhost",

  user: "root",

  password: "root"

});

con.connect(function(err) {

  if (err) throw err;

  console.log("Connected!");

});

3. Test

node server.js

4. Output

Server running on9000

Connected!

Code to select data from the Table

var express = require('express');

var app = express();

var mysql      = require('mysql');

var connection = mysql.createConnection({

  host     : 'localhost',

  user     : 'root',

  password : 'root',

  database : 'DBNAME'

});

module.exports = function(app, db) {

  app.get('/myapp', (req, res) => {

 connection.query('select * from TABLE where ID = 2001', function (error, results, fields) {

    if (error) throw error;

    res.send(results[0]);

  });

  });

};