PHP를 사용하여 간단한 장바구니 기능을 구현하는 방법

CREATE DATABASE shopping_cart;
USE shopping_cart;

CREATE TABLE cart(
    id INT AUTO_INCREMENT PRIMARY KEY,
    product_name VARCHAR(50),
    price DECIMAL(10,2),
    quantity INT,
    total DECIMAL(10,2)
);

<?php
// 连接数据库
$connection = mysqli_connect("localhost", "username", "password", "shopping_cart");

// 查询所有商品
$query = "SELECT * FROM products";
$result = mysqli_query($connection, $query);

// 遍历商品并显示在页面上
while($row = mysqli_fetch_assoc($result)) {
    echo "<h3>".$row['product_name']."</h3>";
    echo "<p>价格：".$row['price']."</p>";
    echo "<button onclick='addToCart(".$row['id'].")'>添加到购物车</button>";
}

// 关闭数据库连接
mysqli_close($connection);
?>

<script>
function addToCart(productId) {
    // 向后端发送请求，将商品添加到购物车
    var xhr = new XMLHttpRequest();
    xhr.open("POST", "add_to_cart.php", true);
    xhr.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
    xhr.onreadystatechange = function() {
        if (xhr.readyState === 4 && xhr.status === 200) {
            alert("商品已添加到购物车！");
        }
    };
    xhr.send("productId=" + productId);
}
</script>

<?php
// 获取待添加到购物车的商品ID
$productId = $_POST['productId'];

// 根据商品ID查询商品信息
$connection = mysqli_connect("localhost", "username", "password", "shopping_cart");
$query = "SELECT * FROM products WHERE id = '".$productId."'";
$result = mysqli_query($connection, $query);
$product = mysqli_fetch_assoc($result);

// 添加商品到购物车表格中
$insertQuery = "INSERT INTO cart (product_name, price, quantity, total) 
                VALUES ('".$product['product_name']."', '".$product['price']."', 1, '".$product['price']."')";
mysqli_query($connection, $insertQuery);

// 关闭数据库连接
mysqli_close($connection);
?>

<?php
$connection = mysqli_connect("localhost", "username", "password", "shopping_cart");

$query = "SELECT * FROM cart";
$result = mysqli_query($connection, $query);

$totalPrice = 0;

while($row = mysqli_fetch_assoc($result)) {
    echo "<h3>".$row['product_name']."</h3>";
    echo "<p>价格：".$row['price']."</p>";
    echo "<p>数量：".$row['quantity']."</p>";
    echo "<hr>";
    // 计算总金额
    $totalPrice += $row['total'];
}

echo "<h4>总金额：".$totalPrice."</h4>";

mysqli_close($connection);
?>