php实现简单购物车

PHP 实现简单购物车

创建数据库表结构

购物车功能通常需要数据库支持。创建一个简单的 cart 表：

CREATE TABLE cart (
    id INT AUTO_INCREMENT PRIMARY KEY,
    product_id INT NOT NULL,
    quantity INT NOT NULL,
    user_id INT NOT NULL,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

连接数据库

使用 PDO 连接数据库：

$host = 'localhost';
$dbname = 'your_database';
$username = 'your_username';
$password = 'your_password';

try {
    $pdo = new PDO("mysql:host=$host;dbname=$dbname", $username, $password);
    $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
} catch (PDOException $e) {
    die("Connection failed: " . $e->getMessage());
}

添加商品到购物车

处理表单提交并将商品添加到购物车：

if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['add_to_cart'])) {
    $productId = $_POST['product_id'];
    $quantity = $_POST['quantity'];
    $userId = 1; // 假设用户ID为1，实际应用中应从会话获取

    $stmt = $pdo->prepare("INSERT INTO cart (product_id, quantity, user_id) VALUES (?, ?, ?)");
    $stmt->execute([$productId, $quantity, $userId]);

    header("Location: cart.php");
    exit;
}

显示购物车内容

查询并显示当前用户的购物车内容：

$userId = 1; // 假设用户ID为1
$stmt = $pdo->prepare("SELECT * FROM cart WHERE user_id = ?");
$stmt->execute([$userId]);
$cartItems = $stmt->fetchAll(PDO::FETCH_ASSOC);

foreach ($cartItems as $item) {
    echo "Product ID: " . $item['product_id'] . "<br>";
    echo "Quantity: " . $item['quantity'] . "<br><br>";
}

更新购物车商品数量

处理更新购物车商品数量的请求：

if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['update_cart'])) {
    $cartId = $_POST['cart_id'];
    $newQuantity = $_POST['quantity'];

    $stmt = $pdo->prepare("UPDATE cart SET quantity = ? WHERE id = ?");
    $stmt->execute([$newQuantity, $cartId]);

    header("Location: cart.php");
    exit;
}

从购物车移除商品

处理从购物车删除商品的请求：

if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['remove_from_cart'])) {
    $cartId = $_POST['cart_id'];

    $stmt = $pdo->prepare("DELETE FROM cart WHERE id = ?");
    $stmt->execute([$cartId]);

    header("Location: cart.php");
    exit;
}

计算购物车总价

计算购物车中所有商品的总价格：

$total = 0;
$stmt = $pdo->prepare("SELECT c.quantity, p.price FROM cart c JOIN products p ON c.product_id = p.id WHERE c.user_id = ?");
$stmt->execute([$userId]);
$items = $stmt->fetchAll(PDO::FETCH_ASSOC);

foreach ($items as $item) {
    $total += $item['quantity'] * $item['price'];
}

echo "Total: $" . number_format($total, 2);

使用会话实现临时购物车

如果不使用数据库，可以使用 PHP 会话实现临时购物车：

session_start();

if (!isset($_SESSION['cart'])) {
    $_SESSION['cart'] = [];
}

// 添加商品
if (isset($_POST['add_to_cart'])) {
    $productId = $_POST['product_id'];
    $quantity = $_POST['quantity'];

    if (isset($_SESSION['cart'][$productId])) {
        $_SESSION['cart'][$productId] += $quantity;
    } else {
        $_SESSION['cart'][$productId] = $quantity;
    }
}

// 显示购物车
foreach ($_SESSION['cart'] as $productId => $quantity) {
    echo "Product ID: $productId, Quantity: $quantity<br>";
}

这个实现提供了基本的购物车功能，可以根据实际需求进行扩展和完善。