php购物车实现流程

PHP 购物车实现流程

数据库设计 创建必要的数据库表，通常包括products（商品表）、users（用户表）和cart（购物车表）。商品表存储商品信息，用户表存储用户信息，购物车表关联用户和商品。

CREATE TABLE products (
    id INT AUTO_INCREMENT PRIMARY KEY,
    name VARCHAR(100),
    price DECIMAL(10, 2),
    description TEXT
);

CREATE TABLE users (
    id INT AUTO_INCREMENT PRIMARY KEY,
    username VARCHAR(50),
    password VARCHAR(255)
);

CREATE TABLE cart (
    id INT AUTO_INCREMENT PRIMARY KEY,
    user_id INT,
    product_id INT,
    quantity INT,
    FOREIGN KEY (user_id) REFERENCES users(id),
    FOREIGN KEY (product_id) REFERENCES products(id)
);

用户登录与会话管理 用户登录后，使用PHP的session机制保存用户ID，确保购物车数据与用户关联。

session_start();
if ($_SERVER['REQUEST_METHOD'] == 'POST' && isset($_POST['login'])) {
    $username = $_POST['username'];
    $password = $_POST['password'];
    // 验证用户信息
    $_SESSION['user_id'] = $user_id; // 假设验证通过
}

商品展示 从数据库中查询商品信息并展示在页面上，通常使用循环输出商品列表。

$sql = "SELECT * FROM products";
$result = $conn->query($sql);
while ($row = $result->fetch_assoc()) {
    echo "<div class='product'>
            <h3>{$row['name']}</h3>
            <p>价格: {$row['price']}</p>
            <form method='post' action='add_to_cart.php'>
                <input type='hidden' name='product_id' value='{$row['id']}'>
                <input type='number' name='quantity' value='1' min='1'>
                <button type='submit'>加入购物车</button>
            </form>
          </div>";
}

添加商品到购物车 处理用户提交的表单数据，将商品添加到购物车表中。

session_start();
if (isset($_SESSION['user_id']) && isset($_POST['product_id'])) {
    $user_id = $_SESSION['user_id'];
    $product_id = $_POST['product_id'];
    $quantity = $_POST['quantity'];
    // 检查是否已存在
    $sql = "INSERT INTO cart (user_id, product_id, quantity) VALUES (?, ?, ?)
            ON DUPLICATE KEY UPDATE quantity = quantity + VALUES(quantity)";
    $stmt = $conn->prepare($sql);
    $stmt->bind_param("iii", $user_id, $product_id, $quantity);
    $stmt->execute();
}

购物车页面展示 查询购物车表中的数据，并计算总价。

session_start();
if (isset($_SESSION['user_id'])) {
    $user_id = $_SESSION['user_id'];
    $sql = "SELECT p.id, p.name, p.price, c.quantity 
            FROM cart c 
            JOIN products p ON c.product_id = p.id 
            WHERE c.user_id = ?";
    $stmt = $conn->prepare($sql);
    $stmt->bind_param("i", $user_id);
    $stmt->execute();
    $result = $stmt->get_result();
    $total = 0;
    while ($row = $result->fetch_assoc()) {
        $subtotal = $row['price'] * $row['quantity'];
        $total += $subtotal;
        echo "<div class='cart-item'>
                <p>{$row['name']} x {$row['quantity']} = {$subtotal}</p>
                <a href='remove_from_cart.php?product_id={$row['id']}'>移除</a>
              </div>";
    }
    echo "<p>总价: {$total}</p>";
}

移除商品 从购物车中删除指定商品。

session_start();
if (isset($_SESSION['user_id']) && isset($_GET['product_id'])) {
    $user_id = $_SESSION['user_id'];
    $product_id = $_GET['product_id'];
    $sql = "DELETE FROM cart WHERE user_id = ? AND product_id = ?";
    $stmt = $conn->prepare($sql);
    $stmt->bind_param("ii", $user_id, $product_id);
    $stmt->execute();
    header("Location: cart.php");
}

结算功能 结算时清空购物车或生成订单，具体逻辑根据需求实现。

session_start();
if (isset($_SESSION['user_id'])) {
    $user_id = $_SESSION['user_id'];
    $sql = "DELETE FROM cart WHERE user_id = ?";
    $stmt = $conn->prepare($sql);
    $stmt->bind_param("i", $user_id);
    $stmt->execute();
    echo "结算成功，购物车已清空";
}