我正在建立一个订购食品在线网站。基本上，每件商品都有两种尺寸PT和QT，价格不同。如果选择了这两个价格中的一个，我可以添加到购物车。但是有一个问题，例如，如果我选择PT尺寸并已添加到购物车，但如果我想稍后更改为QT尺寸，则无法执行此操作。我不知道这个错误在哪里。请看一下我的代码并帮我解决这个问题。谢谢。
数据库（表名是项目）：
________________________________________________________________________________________________________________
id | product_code | product_name | product_desc | product_img_name | price | priceBig | product_type
-------+--------------+--------------------+--------------+------------------+-------+----------+---------------
1 | HS02 | Chicken Fried Rice | | 2.png | 5.50 | 7.50 | house_specials
的index.php
$results = $mysqli->query("SELECT * FROM items WHERE product_type='house_specials' ORDER BY id ASC");
if ($results) {
while($obj = $results->fetch_object()) {
echo '<div class="product">';
echo '<form method="post" action="cart_update.php">';
echo '<div class="product-content"><h3>'.$obj->product_name.'</h3>';
echo '<div class="product-desc">'.$obj->product_desc.'</div>';
echo '<div class="product-info">';
echo 'PT '.$currency.$obj->price.'<input id="pt" type="radio" name="productSize" value="'.$obj->price.'" checked="checked" />';
echo 'QT '.$currency.$obj->priceBig.'<input id="qt" class="size_butt" type="radio" name="productSize" value="'.$obj->priceBig.'"/>';
// echo 'Price '.$currency.$obj->price.' | ';
echo 'Qty <input class="qtyBox" type="number" min="0" name="product_qty" value="1" size="3" min="0" />';
echo '<button class="add_to_cart">Add To Cart</button>';
echo '</div></div>';
echo '<input type="hidden" name="product_code" value="'.$obj->product_code.'" />';
echo '<input type="hidden" name="type" value="add" />';
echo '<input type="hidden" name="return_url" value="'.$current_url.'" />';
echo '</form>';
echo '</div>';
}
}
<h2>Your Cart</h2>
<?php
if(isset($_SESSION["items"]))
{
$total = 0;
echo '<ol>';
if (isset($_SESSION["items"])) {
foreach ($_SESSION["items"] as $cart_itm)
{
echo '<li class="cart-itm">';
echo '<span class="remove-itm"><a href="cart_update.php?removep='.$cart_itm["code"].'&return_url='.$current_url.'">×</a></span>';
echo '<h3>'.$cart_itm["name"].'</h3>';
echo '<div class="p-code">P code : '.$cart_itm["code"].'</div>';
echo '<div class="p-qty">Qty : '.$cart_itm["qty"].'</div>';
echo '<div class="p-price">Price :'.$currency.$cart_itm["price"].'</div>';
echo '</li>';
$subtotal = ($cart_itm["price"]*$cart_itm["qty"]);
$total = ($total + $subtotal);
}
echo '</ol>';
echo '<span class="check-out-txt"><strong>Total : '.$currency.$total.'</strong> <a href="view_cart.php"><button>Check-out!</button></a></span>';
echo '<span class="empty-cart"><a href="cart_update.php?emptycart=1&return_url='.$current_url.'"><button>Empty Cart</button></a></span>';
}
} else {
echo 'Your cart is empty';
}
update_cart
//add item in shopping cart
if(isset($_POST["type"]) || $_POST["type"]=='add')
{
$product_code = filter_var($_POST["product_code"], FILTER_SANITIZE_STRING); //product code
$product_qty = filter_var($_POST["product_qty"], FILTER_SANITIZE_NUMBER_INT); //product code
$price_big = $_POST["priceBig"];
$return_url = base64_decode($_POST["return_url"]); //return url
$productSize = (isset($_GET['productSize']) ? $_GET['productSize'] : null);
//limit quantity for single product
if($product_qty > 10){
die('<div align="center">Please contact us for order of more than 10 quantity!<br /><a href="index.php">Continue to shopping</a>.</div>');
}
//MySqli query - get details of item from db using product code
$results = $mysqli->query("SELECT product_name, price, priceBig FROM items WHERE product_code='$product_code' AND priceBig='$price_big' LIMIT 1");
$obj = $results->fetch_object();
if ($results) { //we have the product info
//prepare array for the session variable
$new_product = array(array('name'=>$obj->product_name, 'code'=>$product_code, 'qty'=>$product_qty, 'price'=>$_POST["productSize"], 'priceBig'=>$obj->priceBig));
if(isset($_SESSION["items"])) //if we have the session
{
$found = false; //set found item to false
foreach ($_SESSION["items"] as $cart_itm) //loop through session array
{
if($cart_itm["code"] == $product_code){ //the item exist in array
$product[] = array('name'=>$cart_itm["name"], 'code'=>$cart_itm["code"], 'price_b'=>$cart_itm["price_b"], 'qty'=>$product_qty, 'price'=>$cart_itm["price"], 'priceBig'=>$cart_itm["priceBig"]);
$found = true;
}else{
//item doesn't exist in the list, just retrive old info and prepare array for session var
$product[] = array('name'=>$cart_itm["name"], 'code'=>$cart_itm["code"], 'qty'=>$cart_itm["qty"], 'price'=>$cart_itm["price"], 'priceBig'=>$cart_itm["priceBig"]);
}
}
if($found == false) //we didn't find item in array
{
//add new user item in array
$_SESSION["items"] = array_merge($product, $new_product);
}else{
//found user item in array list, and increased the quantity
$_SESSION["items"] = $product;
}
}else{
//create a new session var if does not exist
$_SESSION["items"] = $new_product;
// $ans = (isset($_GET['productSize']) ? $_GET['productSize'] : null);
// if ($ans == "PT") {
// $_SESSION["items"] = $new_product;
// } else if ($ans == "QT") {
// $_SESSION["items"] = $new_product;
// }
}
}
//redirect back to original page
header('Location:'.$return_url);
}
答案 0 :(得分：2)
我个人主张创建各自完成自己工作的功能（或类/方法）。在这种情况下，我会说你应该这样做，并改变你的会话数组，如下所示：
function addToCart($item)
{
if(!isset($_SESSION['cart']))
$_SESSION['cart'] = array();
$item_code = filter_var($item['product_code'], FILTER_SANITIZE_STRING);
$qty = (!is_numeric($item["product_qty"]))? 1 : $item["product_qty"];
$price['l'] = $item["priceBig"];
$price['s'] = $item["price"];
$size = (!empty($item['productSize']))? $item['productSize'] : 's';
if(isset($_SESSION['cart'][$item_code]))
$_SESSION['cart'][$item_code][$size]['qty'] += $qty;
else {
$_SESSION['cart'][$item_code]['price'] = $price;
$_SESSION['cart'][$item_code][$size]['qty'] = $qty;
}
}
function changeItemSize($item_code,$from = 's',$to = 'l',$qty = false)
{
if(isset($_SESSION['cart'][$item_code][$from])) {
if(isset($_SESSION['cart'][$item_code][$to])){
$useQty = (!$qty)? $_SESSION['cart'][$item_code][$from]['qty'] : $qty;
$_SESSION['cart'][$item_code][$to]['qty'] += $useQty;
$remainder = $_SESSION['cart'][$item_code][$from]['qty'] - $useQty;
if($remainder <= 0)
unset($_SESSION['cart'][$item_code][$from]);
else
$_SESSION['cart'][$item_code][$from]['qty'] = $remainder;
}
else {
$_SESSION['cart'][$item_code][$to] = $_SESSION['cart'][$item_code][$from];
unset($_SESSION['cart'][$item_code][$from]);
}
}
}
if(!empty($_REQUEST['add'])) {
addToCart($_REQUEST);
}
elseif(!empty($_REQUEST['change'])) {
$to = $_REQUEST['productSize'];
$from = ($to == 's')? 'l' : 's';
changeItemSize($_REQUEST['product_code'],$from,$to);
}
这会给你一个类似的数组：
Array
(
[cart] => Array
(
[ITM01] => Array
(
[price] => Array
(
[l] => 14
[s] => 10
)
[s] => Array
(
[qty] => 11
)
)
[ITM02] => Array
(
[price] => Array
(
[l] => 15
[s] => 12
)
[l] => Array
(
[qty] => 5
)
)
[ITM05] => Array
(
[price] => Array
(
[l] => 3
[s] => 2
)
[s] => Array
(
[qty] => 18
)
)
[ITM10] => Array
(
[price] => Array
(
[l] => 12
[s] => 10
)
[s] => Array
(
[qty] => 3
)
[l] => Array
(
[qty] => 1
)
)
)
)
更改功能将从大项目扣除到小项目，反之亦然。你可以玩它，但这些都是我推荐的。
编辑：以下是我试图了解上述示例的内容。这不是完美的，但希望你能得到这个想法。我建议你在一个完全不同的空间/页面上这样做，因为你无法弄明白，至少你不会破坏你所拥有的。
情侣笔记：
1）此系统不要求您转到一个新页面来添加商品。这一切都在一页上完成。
2）注意文件夹等，这样你就可以把东西放在正确的位置。
3）最后，这仅供演示，使用风险自负。它并不意味着要复制和粘贴，而是看看是否有任何可能对您有所帮助：
<强> /core/classes/class.ShoppingCart.php
// This class is meant to be help keep your cart consistent and contained
// It has all the very basics
class ShoppingCart
{
private $currency;
public function __construct($currency = '$')
{
$this->setCurrency($currency);
}
public function setCurrency($currency)
{
$this->currency = $currency;
}
public function addToCart($item)
{
if(!isset($_SESSION['cart']))
$_SESSION['cart'] = array();
$item_code = filter_var($item['product_code'], FILTER_SANITIZE_STRING);
$qty = (!is_numeric($item["product_qty"]))? 1 : $item["product_qty"];
$price['qt'] = $item["priceBig"];
$price['pt'] = $item["price"];
$size = (!empty($item['productSize']))? $item['productSize'] : 'pt';
if(isset($_SESSION['cart'][$item_code]))
$_SESSION['cart'][$item_code][$size]['qty'] += $qty;
else {
$_SESSION['cart'][$item_code]['price'] = $price;
$_SESSION['cart'][$item_code][$size]['qty'] = $qty;
}
}
public function changeItemSize($item_code,$from = 'pt',$to = 'qt',$qty = false)
{
if(isset($_SESSION['cart'][$item_code][$from])) {
if(isset($_SESSION['cart'][$item_code][$to])){
$useQty = (!$qty)? $_SESSION['cart'][$item_code][$from]['qty'] : $qty;
$_SESSION['cart'][$item_code][$to]['qty'] += $useQty;
$remainder = $_SESSION['cart'][$item_code][$from]['qty'] - $useQty;
if($remainder <= 0)
unset($_SESSION['cart'][$item_code][$from]);
else
$_SESSION['cart'][$item_code][$from]['qty'] = $remainder;
}
else {
$_SESSION['cart'][$item_code][$to] = $_SESSION['cart'][$item_code][$from];
unset($_SESSION['cart'][$item_code][$from]);
}
}
}
public function removeFromCart($item_code)
{
if(isset($_SESSION['cart'][$item_code]))
unset($_SESSION['cart'][$item_code]);
}
public function getCurrency()
{
return $this->currency;
}
}
<强> /core/classes/class.Products.php
// This is just meant to pull some data from your db related
// to your products. You may see some value in expanding this out
class Products
{
private $con;
public function __construct($mysqli)
{
// You need to include the query function
require_once(FUNCTION_DIR.'/function.query.php');
$this->con = $mysqli;
}
public function getProductDetails($itemCodes = false)
{
if(empty($itemCodes))
return query("SELECT * FROM items ORDER BY id ASC",$this->con);
else {
foreach($itemCodes as $codes) {
$val = preg_replace('/[^a-zA-Z0-9]/','',$codes);
$val = trim($val);
if(empty($val))
continue;
$sql[] = "`product_code` = '{$val}'";
}
return query("SELECT * FROM `items` WHERE ".implode(" OR ",$sql)." ORDER BY `id` ASC",$this->con);
}
}
public function getHouseSpecials()
{
return query("SELECT * FROM items WHERE product_type = 'house_specials' ORDER BY id ASC",$this->con);
}
}
<强> /core/functions/function.cartView.php
我建议将其作为一个包含的html页面，而不是直接写入此函数
// As noted, you would probably save some headache if include() the html
// instead of rendering it in the function directly
function cartView($obj,$currency = '$')
{
ob_start();
?>
<div class="product">
<form method="post" action="">
<div class="product-content">
<h3><?php echo $obj->product_name; ?></h3>
<div class="product-desc"><?php echo $obj->product_desc; ?></div>
<div class="product-info">
<label>
<input id="pt" type="radio" name="productSize" value="pt" checked="checked" />
PT <?php echo $currency.$obj->price; ?>
</label>
<label>
<input id="qt" type="radio" name="productSize" value="qt" class="size_butt" />
QT <?php echo $currency.$obj->priceBig; ?>
</label>
<input type="hidden" name="priceBig" value="<?php echo $obj->priceBig; ?>" />
<input type="hidden" name="price" value="<?php echo $obj->price; ?>" />
Qty <input class="qtyBox" type="number" name="product_qty" value="1" size="3" min="0" />
<input type="submit" name="add" class="add_to_cart" value="Add To Cart" />
</div>
</div>
<input type="hidden" name="product_code" value="<?php echo $obj->product_code; ?>" />
</form>
</div>
<?php
$data = ob_get_contents();
ob_end_clean();
return $data;
}
<强> /core/functions/function.renderCart.php
我没有完成这个功能，但你应该能够搞清楚。它从$itemsInCart获取详细信息，并从循环购物车中填充详细信息。 return之后的所有内容都无效
function renderCart($mysqli,$itemsInCart,$currency = '$')
{
if(empty($_SESSION["cart"]))
return 'Your cart is empty.';
print_r($itemsInCart);
return;
ob_start();
?>
<ol>
<?php if(!empty($_SESSION["cart"])) {
foreach ($_SESSION["cart"] as $itemCode => $cart_itm) {
?> <li class="cart-itm">
<span class="remove-itm"><a href="?remove=true&product_code=<?php echo $cart_itm["code"]; ?>">×</a></span>
<h3><?php echo $cart_itm["name"]; ?></h3>
<div class="p-code">P code : <?php echo $cart_itm["code"]; ?></div>
<div class="p-qty">Qty : <?php echo $cart_itm["qty"]; ?></div>
<div class="p-price">Price :<?php echo $currency.$cart_itm["price"]; ?></div>
</li>
<?php $subtotal = ($cart_itm["price"]*$cart_itm["qty"]);
$total = (0 + $subtotal);
}
?> </ol>
<span class="check-out-txt"><strong>Total : <?php echo $currency.$total; ?></strong> <a href="view_cart.php"><button>Check-out!</button></a></span>
<span class="empty-cart"><a href="cart_update.php?emptycart=1"><button>Empty Cart</button></a></span>
<?php
}
$data = ob_get_contents();
ob_end_clean();
return $data;
}
<强> /core/functions/function.query.php
// This is just a fast and dirty way to run a query and return an array
// It's meant to return, so it's really only good for select statements
function query($sql,$mysqli)
{
$results = $mysqli->query($sql);
if(!$results)
return 0;
while($obj = $results->fetch_object()) {
$row[] = $obj;
}
return (!empty($row))? $row : array();
}
<强> /config.php
// If you don't have some sort of config file with some simple defines and such
// I would encourage it so it's easier to keep track of files and allow
// for the re-use of common elements
//*** Include your database file ***//
// Create some defines (if you don't already have some)
define('ROOT_DIR',__DIR__);
define('CLASS_DIR',ROOT_DIR.'/core/classes');
define('FUNCTION_DIR',ROOT_DIR.'/core/functions');
// Autoload classes
spl_autoload_register(function($class){
if(class_exists($class))
return;
if(is_file($file = CLASS_DIR.'/class.'.$class.'.php'))
include_once($file);
});
<强>的index.php
// Include config
require_once(__DIR__.'/config.php');
// Include the required functions to render
require_once(FUNCTION_DIR.'/function.cartView.php');
require_once(FUNCTION_DIR.'/function.renderCart.php');
// Create instance of products
$pEngine = new Products($mysqli);
// Create shopping cart
$shopEngine = new ShoppingCart('$');
// Do the cart actions if prompted
if(!empty($_REQUEST['add']))
$shopEngine->addToCart($_REQUEST);
elseif(!empty($_REQUEST['change'])) {
$to = $_REQUEST['productSize'];
$from = ($to == 'pt')? 'qt' : 'pt';
$shopEngine->changeItemSize($_REQUEST['product_code'],$from,$to);
}
elseif(!empty($_REQUEST['remove']))
$shopEngine->removeFromCart($_REQUEST['product_code']);
// Quick render of the cart
// This is retrieved from your products list
// This is just an example
$prods = $pEngine->getHouseSpecials();
foreach($prods as $items) {
echo cartView((object)$items);
}
// Quick demonstration of the session
if(!empty($_SESSION['cart'])) {
$details = $pEngine->getProductDetails(array_keys($_SESSION['cart']));
// you would just render the cart here
// This function does not work, I didn't have time
// to finish it...use print_r($details) to see what it returns
// echo renderCart($mysqli,$details,'$');
foreach($itemsInCart as $item_codes) {
if(isset($_SESSION['cart'][$item_codes]['qt']))
echo '<a href="?change=true&product_code='.$item_codes.'&productSize=pt">Item Change to Small</a></br />';
if(isset($_SESSION['cart'][$item_codes]['pt']))
echo '<a href="?change=true&product_code='.$item_codes.'&productSize=qt">Item Change to Large</a></br />';
echo '<a href="?remove=true&product_code='.$item_codes.'">Remove</a></br />';
}
}