我目前正在开展一个小型大学项目。开发一个基本的电子商务php网站。我们在研讨会上获得了代码或提供的代码，然后我们将根据我们的需求进行定制/开发。
我正在尝试调整以下代码以添加其他信息。 cart.php代码构建购物车功能，显示产品名称，数量，然后允许用户增加/减少数量。
我正在尝试将用户（选定的）产品尺寸添加到购物车。他们可以在product.php上选择。我已经在product.php中为此创建了数据库支持我只需要用户选择的选项然后出现在cart.php中。
我不完全确定如何正确地做到这一点。我的第一个问题是如何将product.php中的用户选择记录到一个变量中，该变量可以转移到cart.php。
第二个问题是如何修改cart.php来执行此操作，您将在cart.php中看到我试图将产品大小添加到表中。
我真的很感激这方面的一些指导。
Product.php
<div align="center"><?php
session_start();
//Connect to Session
include "conn.php";
//Retrieve Header
include "header.php";
//Query
//Get Product ID
if (isset($_GET['id'])){
$product_id = $_GET['id'];
//Select Product Attributes Query where Product ID is the selected product ID
$q="SELECT ProductName,img,ProductID,Description,p_spec1,p_spec2,p_spec3,p_spec4,p_spec5,Price,size_1,size_2,size_3,size_4,size_5 FROM Products
WHERE ProductID=$product_id";
//Retrieve and excute query from database and save results into a variable
$result = mysqli_query($_SESSION['conn'],$q);
//Display Product
if ($row = mysqli_fetch_array($result)){ //Create Product Attribute Array
echo "<div>
<p><b>Name:</b>" .$row[0]."</p>
<p><img src=".$row[1]."></p>
<p><b>Product Code:</b>" .$row[2]."</p>
<p><b><u>Product Description:</b></u></p>
<p>".$row[3]."</p>
<p><b><u>Product Spec:</b></u>";
//Count total product specifications and adjust bullet points
for($i=4;$i<9;$i++) {
if($row[$i]!='')
echo "<li>".$row[$i]."</li>";
}
echo"
<p><b>Price: </b>£".$row[9]."</p>
<p><b>Size:</b><select>";
//Count total product sizes available and adjust drop-down menu
for($i=10;$i<15;$i++) {
if($row[$i]!='')
echo "<option>".$row[$i]."</option>";
}
echo"</select>
</p>
</p>
</div>";
}
//Add Item to basket
echo "<div><a href=\"cart.php?action=add&product=$product_id,$product_size\"><input type='submit' value='Add to Basket'</a></div>";
}
//Retrieve Footer
include "footer.php";
?>
</div>
我在product.php中假设需要将变量$ product_size操作到cart.php，但是如何将用户选择收集到变量中呢？
Cart.php
<?php
//Start Session
session_start();
include "conn.php"; //Connect to database
include "header.php"; //Retrieve Header
//View the current shopping cart session
function viewcart(){
if (isset($_SESSION['cart'])){ //if shopping cart is not empty
$cart = $_SESSION['cart']; //store the cart array into a variable then display the content
echo "<table border=\"1\"> <tr> <th>Product</th> <th>Size</th> <th>Quantity</th> <th>Action</th></tr>";
foreach ($cart as $product=>$quantity){
$q = "SELECT ProductID FROM Products WHERE ProductName = '$product' LIMIT 1";
$result = mysqli_query($_SESSION['conn'],$q);
$row = mysqli_fetch_array($result);
$product_id = $row['ProductID'];
echo "<tr><td>$product</td>
<td>$product_size</td>
<td>$quantity</td><td>
<a href=\"?action=delete&product=$product_id\">-</a>
<a href=\"?action=add&product=$product_id\">+</a> </td> </tr>";
mysqli_free_result($result);
}
echo "</table>";
subtotal($cart); //display the subtotal
} else { //if shopping cart is empty
echo "<p>Your Basket is empty.</p>";
}
}
function subtotal($cart){
$total = 0; //initialise total
if (!empty($cart)){
foreach ($cart as $product => $quantity){
$q = "SELECT Price FROM Products WHERE ProductName ='$product' LIMIT 1";
$result = mysqli_query($_SESSION['conn'],$q);
$row = mysqli_fetch_array($result);
$price = $row['Price'];
$total += $price * $quantity;
}
echo "<p>Total: £$total |
<a href=\"?action=empty\">Empty cart</a></p>";
} else {
unset($_SESSION['cart']); //destroy empty cart
echo "<p>Your Basket is empty.</p>";
}
}
function addproduct($product_id, $product_qty){
$q = "SELECT ProductName FROM Products WHERE ProductID = $product_id LIMIT 1";
$result = mysqli_query($_SESSION['conn'],$q);
$row = mysqli_fetch_array($result);
$product_name = $row['ProductName']; //get the product name from product id because it is better to display name than id in the cart
if (isset($_SESSION['cart'])){ //if shopping cart is not empty
$cart = $_SESSION['cart'];
if (array_key_exists($product_name, $cart)){ //if the product exists, update quantity
$cart[$product_name] += $product_qty;
}
else { //otherwise, add new product-quantity pair to the array
$cart[$product_name]=$product_qty;
}
$_SESSION['cart'] = $cart; //write the updated array back to session variable
}
else { //if shopping cart is empty
$cart = array($product_name=>$product_qty); //add product and quantity to the shopping cart
$_SESSION['cart'] = $cart; //write the updated array back
}
mysqli_free_result($result);
}
function deleteproduct($product_id, $product_qty){
$q = "SELECT ProductName FROM Products WHERE ProductID = $product_id LIMIT 1";
$result = mysqli_query($_SESSION['conn'],$q);
$row = mysqli_fetch_array($result);
$product_name = $row['ProductName'];
if (isset($_SESSION['cart'])){ //if shopping cart is not empty
$cart = $_SESSION['cart'];
if (array_key_exists($product_name, $cart)){ //if product exists, update quantity
$cart[$product_name] -= $product_qty;
if ($cart[$product_name] == 0){ //if the qty 0, delete key
unset($cart[$product_name]);
}
}
else { //exception
echo "<p>Error!</p>";
}
$_SESSION['cart'] = $cart; //write array back to session variable
} else {
echo "<p>Error!</p>";
}
mysqli_free_result($result);
}
function emptycart(){
if (isset($_SESSION['cart'])){ //if shopping cart is not empty
unset($_SESSION['cart']);
}
else {
echo "<p>Error!</p>";
}
}
if (isset($_GET['action'])){
if ($_GET['action']=='view'){
viewcart();
} elseif ($_GET['action']=='add'){
if (isset($_GET['product'])){
$product_id = $_GET['product'];
$product_qty = 1; //default product value
addproduct($product_id, $product_qty);
viewcart();
} else {
echo "<p>There is an error?</p>";
}
}
elseif ($_GET['action'] == 'delete'){
if (isset($_GET['product'])){
$product_id = $_GET['product'];
$product_qty = 1; //default product value
deleteproduct($product_id, $product_qty);
viewcart();
}
else {
echo "<p>There is an error!</p>";
}
} elseif ($_GET['action']=='empty') {
emptycart();
viewcart();
}
else {
echo "<p>There is an error! </p>";
}
}
else { echo "<p>There is an error!</p>"; }
include "footer.php"; //template design part
?>
P.S我知道SQL注入问题。
谢谢！
答案 0 :(得分：1)
我前段时间构建了类似于此的东西，并面临同样（相当常见）的问题。
该解决方案要求您创建一个会话变量来存储所选的产品ID。我想我在会话中存储了一个或多个数组，并使用这些信息来填充结帐页面。
我还将会话数据存储在一个表中，以便用户可以在会话之间访问它， 但这是一个更高级的功能。
Take Away：使用会话变量来存储产品ID的数组
答案 1 :(得分：0)
这里有一些根本性的缺陷。
首先，创建有效的HTML。确保表单包含在<form></form>标记中。该表单应该有一个操作：<form action="cart.php" method="POST">
您选择的“尺寸”需要有一个名称：<select name="productSize">。