PHP + MySQL Tutorial: Implementing a RESTful API from Scratch

In modern development, RESTful APIs have become a standard for communication between applications. These interfaces facilitate interoperability and flexibility across various platforms. This tutorial is designed to guide you through creating a RESTful API using PHP and MySQL, focusing on the complete implementation of CRUD (Create, Read, Update, Delete) operations. Understanding the RESTful Approach: Before diving into the technical implementation, it\'s crucial to understand what RESTful actually means. REST APIs use HTTP to perform operations, respecting verbs like GET, POST, PUT, and DELETE. This not only standardizes actions within an API but also adds simplicity and ease of use.

Unlike other architectures such as SOAP, REST APIs are usually lighter and less complex in their implementation. Its design is based on resources represented by unique URLs.

Project Structure

Our application will consist of several files that will manage the different parts of the code:

File	Function
db.php	Managing connections to MySQL.
api.php	Main entry point for handling requests HTTP.
model.php	Business logic and database access.
index.php	Web client homepage (optional).

Setting up the environment

Make sure you have a web server like Apache or Nginx set up along with PHP and MySQL. You can use solutions like XAMPP, WAMP, or LAMP depending on your operating system. Additionally, verify that you have correctly configured an IDE or text editor such as Visual Studio Code or Sublime Text to write your code.

Connecting to MySQL

Create a file called db.php. This file will be where we will establish the connection to our database:

<?php
$host = localhost;
$db = api_database;
$user = root;
$pass = ;
$charset = utf8mb4;
$dsn = \"mysql:host=$host;dbname=$db;charset=$charset\";
$options = [
 PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
 PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
 PDO::ATTR_EMULATE_PREPARES => false,
];
?>

Creating the RESTful model

Create a file model.php. Here we will handle all interactions with our database. Make sure to include functions for each CRUD operation:

// Get all records
function getAllItems($pdo) {
    $stmt = $pdo->query(SELECT * FROM items);
    return $stmt->fetchAll();
}
// Additional functions to create, update, and delete records
?>

Handling requests with api.php

Our main file, api.php, will be responsible for handling incoming HTTP requests, directing them to the appropriate model for processing:

// Code to handle GET, POST, PUT, DELETE
// Based on the received HTTP verb, direct to the appropriate functions
?>

As you complete these stages, you will have a functional API using PHP and MySQL that follows RESTful principles. This not only improves code organization but also facilitates future expansion if you decide to integrate additional layers such as authentication or advanced validations.