Простейшее CRUD приложение PHP

index.php

<?php
$host = '127.0.0.1';
$db   = 'database';
$user = 'username';
$pass = 'password';
$charset = 'utf8mb4';

$dsn = "mysql:host=$host;dbname=$db;charset=$charset";
$opt = [
    PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
    PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
    PDO::ATTR_EMULATE_PREPARES   => false,
];
$pdo = new PDO($dsn, $user, $pass, $opt);

function getProducts($pdo) {
    $stmt = $pdo->query('SELECT * FROM products');
    return $stmt->fetchAll();
}

function getProduct($pdo, $id) {
    $stmt = $pdo->prepare('SELECT * FROM products WHERE id = ?');
    $stmt->execute([$id]);
    return $stmt->fetch();
}

function createProduct($pdo, $name, $description, $price) {
    $stmt = $pdo->prepare('INSERT INTO products (name, description, price) VALUES (?, ?, ?)');
    $stmt->execute([$name, $description, $price]);
    return $pdo->lastInsertId();
}

function updateProduct($pdo, $id, $name, $description, $price) {
    $stmt = $pdo->prepare('UPDATE products SET name = ?, description = ?, price = ? WHERE id = ?');
    $stmt->execute([$name, $description, $price, $id]);
}

function deleteProduct($pdo, $id) {
    $stmt = $pdo->prepare('DELETE FROM products WHERE id = ?');
    $stmt->execute([$id]);
}

// Роутинг и форматирование ответа в JSON
$request = $_SERVER['REQUEST_URI'];
$method = $_SERVER['REQUEST_METHOD'];

header('Content-Type: application/json');

switch ($request) {
    case '/products' :
        if($method == 'GET'){
            echo json_encode(getProducts($pdo));
        } elseif ($method == 'POST') {
            $name = $_POST['name'];
            $description = $_POST['description'];
            $price = $_POST['price'];
            echo json_encode(createProduct($pdo, $name, $description, $price));
        }
        break;
    case strpos($request, '/product') !== false :
        $id = explode('/',$request)[2];
        if($method == 'GET'){
            echo json_encode(getProduct($pdo, $id));
        } elseif ($method == 'PUT') {
            parse_str(file_get_contents('php://input'), $_PUT);
            $name = $_PUT['name'];
            $description = $_PUT['description'];
            $price = $_PUT['price'];
            updateProduct($pdo, $id, $name, $description, $price);
        } elseif ($method == 'DELETE') {
            deleteProduct($pdo, $id);
        }
        break;
    default:
        http_response_code(404);
        break;
}