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php购物车功能实现

2026-01-15 13:03:31PHP

数据库设计

购物车功能通常需要设计数据库表来存储商品和用户信息。常见的表包括：

products 表：存储商品信息，如商品ID、名称、价格、库存等。
users 表：存储用户信息，如用户ID、用户名、密码等。
cart 表：存储购物车信息，如购物车ID、用户ID、商品ID、数量等。

示例SQL创建表语句：

CREATE TABLE products (
    id INT AUTO_INCREMENT PRIMARY KEY,
    name VARCHAR(100) NOT NULL,
    price DECIMAL(10, 2) NOT NULL,
    stock INT NOT NULL
);

CREATE TABLE users (
    id INT AUTO_INCREMENT PRIMARY KEY,
    username VARCHAR(50) NOT NULL,
    password VARCHAR(255) NOT NULL
);

CREATE TABLE cart (
    id INT AUTO_INCREMENT PRIMARY KEY,
    user_id INT NOT NULL,
    product_id INT NOT NULL,
    quantity INT NOT NULL,
    FOREIGN KEY (user_id) REFERENCES users(id),
    FOREIGN KEY (product_id) REFERENCES products(id)
);

添加商品到购物车

通过PHP处理表单提交，将商品添加到购物车。需要检查商品是否已存在，若存在则更新数量，否则插入新记录。

php购物车功能实现

<?php
session_start();
require 'db_connection.php';

if (isset($_POST['add_to_cart'])) {
    $product_id = $_POST['product_id'];
    $user_id = $_SESSION['user_id'];
    $quantity = $_POST['quantity'];

    // 检查商品是否已在购物车
    $stmt = $pdo->prepare("SELECT * FROM cart WHERE user_id = ? AND product_id = ?");
    $stmt->execute([$user_id, $product_id]);
    $existing_item = $stmt->fetch();

    if ($existing_item) {
        // 更新数量
        $new_quantity = $existing_item['quantity'] + $quantity;
        $stmt = $pdo->prepare("UPDATE cart SET quantity = ? WHERE id = ?");
        $stmt->execute([$new_quantity, $existing_item['id']]);
    } else {
        // 插入新记录
        $stmt = $pdo->prepare("INSERT INTO cart (user_id, product_id, quantity) VALUES (?, ?, ?)");
        $stmt->execute([$user_id, $product_id, $quantity]);
    }
    header("Location: cart.php");
}
?>

显示购物车内容

从数据库中查询购物车内容，并显示商品详细信息。

<?php
session_start();
require 'db_connection.php';

$user_id = $_SESSION['user_id'];
$stmt = $pdo->prepare("
    SELECT cart.id, products.name, products.price, cart.quantity 
    FROM cart 
    JOIN products ON cart.product_id = products.id 
    WHERE cart.user_id = ?
");
$stmt->execute([$user_id]);
$cart_items = $stmt->fetchAll();

$total = 0;
foreach ($cart_items as $item) {
    $total += $item['price'] * $item['quantity'];
}
?>

<ul>
<?php foreach ($cart_items as $item): ?>
    <li>
        <?php echo htmlspecialchars($item['name']); ?> - 
        $<?php echo htmlspecialchars($item['price']); ?> x 
        <?php echo htmlspecialchars($item['quantity']); ?> = 
        $<?php echo htmlspecialchars($item['price'] * $item['quantity']); ?>
        <a href="remove_from_cart.php?id=<?php echo $item['id']; ?>">Remove</a>
    </li>
<?php endforeach; ?>
</ul>
<p>Total: $<?php echo $total; ?></p>

从购物车移除商品

处理移除商品的请求，从数据库中删除对应的记录。

php购物车功能实现

<?php
session_start();
require 'db_connection.php';

if (isset($_GET['id'])) {
    $cart_id = $_GET['id'];
    $user_id = $_SESSION['user_id'];

    // 验证购物车项属于当前用户
    $stmt = $pdo->prepare("DELETE FROM cart WHERE id = ? AND user_id = ?");
    $stmt->execute([$cart_id, $user_id]);
}
header("Location: cart.php");
?>

更新购物车商品数量

通过表单提交更新购物车中商品的数量。

<?php
session_start();
require 'db_connection.php';

if (isset($_POST['update_cart'])) {
    $cart_id = $_POST['cart_id'];
    $quantity = $_POST['quantity'];
    $user_id = $_SESSION['user_id'];

    // 验证购物车项属于当前用户
    $stmt = $pdo->prepare("UPDATE cart SET quantity = ? WHERE id = ? AND user_id = ?");
    $stmt->execute([$quantity, $cart_id, $user_id]);
    header("Location: cart.php");
}
?>

会话存储实现

如果不使用数据库，可以使用PHP的$_SESSION来存储购物车数据。

<?php
session_start();

if (isset($_POST['add_to_cart'])) {
    $product_id = $_POST['product_id'];
    $quantity = $_POST['quantity'];

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

    if (isset($_SESSION['cart'][$product_id])) {
        $_SESSION['cart'][$product_id] += $quantity;
    } else {
        $_SESSION['cart'][$product_id] = $quantity;
    }
    header("Location: cart.php");
}
?>