Express JSON REST API with a MySQL database

Recently, I was looking into creating some new views for a older PHP-centric application. Rather than trying to extend the old codebase, I decided to create a separate single page app with Angular 2. Instead of querying the database directly on the server side, I needed to be able to access this over a AJAX call.

I was genuinely surprised how straightforward it was expose the data with the Express framework. All that is needed to make a call is to set up the database connection and a bit of boilerplate to describe the endpoints.

import express = require("express");
import mysql = require("mysql");

let connection = mysql.createConnection({
  host: "localhost",
  user: "user",
  password: "password",
  database: "database"
});
connection.connect();

const app = express();
app.get("/api/customer/:id", (req, res) => {
	const id = req.params.id;
	connection.query(`SELECT * FROM customers
		WHERE id = ${id}
		ORDER BY id DESC`,
	    (err, rows, fields) => {
		 if (err){
			res.json(err);
		}
		res.json(rows);
	});
});

const port = process.env.PORT || 3001;
var server = app.listen(port, () => {
  var port = server.address().port;
  console.log("This express app is listening on port:" + port);
});