مشاريع تطبيقية متكاملة في PHP

CREATE TABLE users (
    id INT AUTO_INCREMENT PRIMARY KEY,
    username VARCHAR(50) NOT NULL UNIQUE,
    password VARCHAR(255) NOT NULL,
    role ENUM('admin', 'editor') NOT NULL
);

CREATE TABLE posts (
    id INT AUTO_INCREMENT PRIMARY KEY,
    title VARCHAR(255) NOT NULL,
    content TEXT NOT NULL,
    author_id INT NOT NULL,
    created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
    FOREIGN KEY (author_id) REFERENCES users(id)
);

<?php
session_start();
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $username = $_POST['username'];
    $password = $_POST['password'];

    $stmt = $conn->prepare("SELECT * FROM users WHERE username = ?");
    $stmt->bind_param("s", $username);
    $stmt->execute();
    $result = $stmt->get_result();
    $user = $result->fetch_assoc();

    if ($user && password_verify($password, $user['password'])) {
        $_SESSION['user'] = $user;
        header("Location: dashboard.php");
        exit;
    } else {
        echo "Invalid credentials";
    }
}
?>

<?php
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $title = $_POST['title'];
    $content = $_POST['content'];
    $author_id = $_SESSION['user']['id'];

    $stmt = $conn->prepare("INSERT INTO posts (title, content, author_id) VALUES (?, ?, ?)");
    $stmt->bind_param("ssi", $title, $content, $author_id);
    $stmt->execute();
    echo "Post added successfully!";
}
?>

<?php
$result = $conn->query("SELECT posts.*, users.username FROM posts JOIN users ON posts.author_id = users.id");
while ($row = $result->fetch_assoc()) {
    echo "<h2>{$row['title']}</h2>";
    echo "<p>{$row['content']}</p>";
    echo "<small>By {$row['username']} on {$row['created_at']}</small>";
}
?>

CREATE TABLE products (
    id INT AUTO_INCREMENT PRIMARY KEY,
    name VARCHAR(255) NOT NULL,
    description TEXT,
    price DECIMAL(10, 2) NOT NULL,
    stock INT DEFAULT 0
);

CREATE TABLE orders (
    id INT AUTO_INCREMENT PRIMARY KEY,
    customer_name VARCHAR(255) NOT NULL,
    total_price DECIMAL(10, 2) NOT NULL,
    created_at DATETIME DEFAULT CURRENT_TIMESTAMP
);

CREATE TABLE order_items (
    id INT AUTO_INCREMENT PRIMARY KEY,
    order_id INT NOT NULL,
    product_id INT NOT NULL,
    quantity INT NOT NULL,
    price DECIMAL(10, 2) NOT NULL,
    FOREIGN KEY (order_id) REFERENCES orders(id),
    FOREIGN KEY (product_id) REFERENCES products(id)
);

<?php
$result = $conn->query("SELECT * FROM products WHERE stock > 0");
while ($row = $result->fetch_assoc()) {
    echo "<h2>{$row['name']}</h2>";
    echo "<p>{$row['description']}</p>";
    echo "<p>Price: {$row['price']}</p>";
    echo "<a href='add_to_cart.php?id={$row['id']}'>Add to Cart</a>";
}
?>

<?php
session_start();
if (!isset($_SESSION['cart'])) {
    $_SESSION['cart'] = [];
}

$product_id = $_GET['id'];
$_SESSION['cart'][$product_id] = ($_SESSION['cart'][$product_id] ?? 0) + 1;
header("Location: cart.php");
?>

<?php
session_start();
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $customer_name = $_POST['customer_name'];
    $total_price = array_sum(array_map(function($product) use ($products) {
        return $products[$product]['price'] * $_SESSION['cart'][$product];
    }, array_keys($_SESSION['cart'])));

    $stmt = $conn->prepare("INSERT INTO orders (customer_name, total_price) VALUES (?, ?)");
    $stmt->bind_param("sd", $customer_name, $total_price);
    $stmt->execute();
    $order_id = $conn->insert_id;

    foreach ($_SESSION['cart'] as $product_id => $quantity) {
        $stmt = $conn->prepare("INSERT INTO order_items (order_id, product_id, quantity, price) VALUES (?, ?, ?, ?)");
        $stmt->bind_param("iiid", $order_id, $product_id, $quantity, $products[$product_id]['price']);
        $stmt->execute();
    }

    $_SESSION['cart'] = [];
    echo "Order placed successfully!";
}
?>