PHP CRUD (Create, Read, Update, Delete) application with a RESTful API twist, built without frameworks. It manages a "Quotes Library" (like a mini-API) and includes PDO, JSON responses, and basic authentication.

<?php

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

header('Access-Control-Allow-Origin: *');

header('Access-Control-Allow-Methods: GET, POST, PUT, DELETE');

header('Access-Control-Allow-Headers: Content-Type');

// ==================== DATABASE SETUP ====================

$host = 'localhost';

$db = 'quotes_db';

$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

];

try {

$pdo = new PDO($dsn, $user, $pass, $options);

} catch (PDOException $e) {

die(json_encode(['error' => 'Database connection failed']));

}

// ==================== API KEY AUTH (SIMPLIFIED) ====================

$valid_api_key = 'secret123';

$api_key = $_SERVER['HTTP_API_KEY'] ?? '';

if ($api_key !== $valid_api_key && $_SERVER['REQUEST_METHOD'] !== 'GET') {

die(json_encode(['error' => 'Invalid API key']));

}

// ==================== CRUD OPERATIONS ====================

$request_method = $_SERVER['REQUEST_METHOD'];

$input_data = json_decode(file_get_contents('php://input'), true);

switch ($request_method) {

case 'GET':

// Read all quotes or single quote

$id = $_GET['id'] ?? null;

if ($id) {

$stmt = $pdo->prepare("SELECT * FROM quotes WHERE id = ?");

$stmt->execute([$id]);

$quote = $stmt->fetch();

echo json_encode($quote ?: ['error' => 'Quote not found']);

} else {

$stmt = $pdo->query("SELECT * FROM quotes");

echo json_encode($stmt->fetchAll());

}

break;

case 'POST':

// Create new quote

$author = $input_data['author'] ?? '';

$text = $input_data['text'] ?? '';

if (empty($author) || empty($text)) {

echo json_encode(['error' => 'Author and text required']);

break;

}

$stmt = $pdo->prepare("INSERT INTO quotes (author, text) VALUES (?, ?)");

$stmt->execute([$author, $text]);

echo json_encode(['success' => 'Quote added', 'id' => $pdo->lastInsertId()]);

break;

case 'PUT':

// Update quote

$id = $input_data['id'] ?? null;

$author = $input_data['author'] ?? '';

$text = $input_data['text'] ?? '';

if (!$id || empty($author) || empty($text)) {

echo json_encode(['error' => 'ID, author, and text required']);

break;

}

$stmt = $pdo->prepare("UPDATE quotes SET author = ?, text = ? WHERE id = ?");

$stmt->execute([$author, $text, $id]);

echo json_encode(['success' => 'Quote updated']);

break;

case 'DELETE':

// Delete quote

$id = $input_data['id'] ?? null;

if (!$id) {

echo json_encode(['error' => 'ID required']);

break;

}

$stmt = $pdo->prepare("DELETE FROM quotes WHERE id = ?");

$stmt->execute([$id]);

echo json_encode(['success' => 'Quote deleted']);

break;

default:

echo json_encode(['error' => 'Method not allowed']);

}

?>