How to use PHP to implement a simple shopping cart function
The shopping cart function is an essential part of an e-commerce website, which allows users to place items they are interested in Add to cart, then proceed to checkout or continue browsing and adding items. This article will introduce how to use PHP to implement a simple shopping cart function and provide specific code examples.
First, we need to create a database and a table for storing shopping cart data.
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) );
Next, we need to create a product list page where users can select products to add to their shopping cart. The following is a simple sample code:
<?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>
In the previous step, we called a function called ## The back-end script of #add_to_cart.php is used to add selected items to the shopping cart. Here is the sample code for the 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); ?>
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