我有一个电子商务网站项目，这是细节，这只是我无法解决的小问题。我有两张桌子，第一张桌子叫做物品，第二张桌子是购物车。我在一个页面中链接了名为“添加到购物车”的链接，将我转换为 cart.php
a href="cart.php? action=add & id=<?php echo $itemId; ?>"> Add to Cart </a><br/>
'<a href="cart.php? action=show & id=<?php echo $itemId; ?> ">View Shopping Cart </a>`
之后我有 cart.php 页面：
<?php
// Script Error Reporting
error_reporting(E_ALL);
ini_set('display_errors', '1');
?>
<html>
<head>
<title> Cart Page </title>
</head>
<body>
<?php
include "function.php";
ConnectToDb( );
$id= $_GET['id'];
$action = $_REQUEST['action'];
$action=(isset($_GET['action']) && $_GET['action'] != '') ? $_GET['action'] : 'view';
switch($action){
case "add":
{$sql=mysql_query("SELECT * FROM items WHERE itemId='$id'");
$row=mysql_fetch_array($sql);
$itemPrice= $row["itemPrice"];
$itemName= $row["itemName"];
$quanty=$row["qty"];
$query="insert into cart values('1',".$_GET[id].",1,".$itemPrice.",".$itemName.")";
$result=mysql_query($query);
header("location:cart.php? action=show ");
echo "Item Was Added";
break;
}
case "remove":
{
$query="delete from cart where itemId=".$_GET['id'];
$result = mysql_query($query);
header("location:cart.php?action=show");
}
case "update":
{
$query="update cart set". $quanty = $_POST['quantity']."where itemId=".$_GET['id'];
$result = mysql_query($query);
header("location:cart.php?action=show");
break;
}
case "show_update":
{
$result = mysql_query("select * from cart");
$uid=$row["uid"];
$itemId= $row["itemId"];
$qty=$row["qty"];
$itemPrice= $row["itemPrice"];
$itemName= $row["itemName"];
while($row = mysql_fetch_array($result))
{ if ($itemId == $id )
{
$totalCost =0;
$query = "select * from cart inner join items on cart.itemId= items.itemId";
$result = mysql_query($query);
echo "<table width ='100%' border ='1'>";
while($row = mysql_fetch_array($result))
{$totalCost += ($qty * $itemPrice);
echo "<tr>";
echo "<td>"; echo $itemName; echo "</td>";
echo "<td> SR"; echo $itemPrice; echo "</td>";
echo "<td> <input type ='text' name='quantity' value=".$qty."</td>";
echo'<td width="23%"><a href="cart.php?action=update&id='.$itemId.'">save</a></td>';
echo'<td width="23%"><a href="cart.php?action=remove&id='.$itemId.'">Remove</a></td>';
echo"</tr>";}
// Increment the total cost of all items
$totalCost += ($row["qty"] * $row["itemPrice"]);
echo "<tr> <td colspan='2'> <a href='products.php'>Keep Shopping</a></td>";
echo "<td colspan='2'> <b>Total: SR".$totalCost."</b></td></tr>";
echo "</table>";
}
else{
$totalCost =0;
$query2 = "select * from cart inner join items on cart.itemId= items.itemId";
$result2 = mysql_query($query2);
echo "<table width ='100%' border ='1'>";
while($row2 = mysql_fetch_array($result2))
{$totalCost += ($row2["qty"] * $row2["itemPrice"]);
echo "<tr>";
echo "<td>"; echo $row2['itemName']; echo "</td>";
echo "<td> SR"; echo $row2["itemPrice"]; echo "</td>";
echo "<td>"; echo $row2["qty"]; echo "</td>";
echo'<td width="23%"><a href="cart.php?action=show_update&id='.$row2["itemId"].">edit</a></td>";
echo'<td width="23%"><a href="cart.php?action=remove&id='.$row2["itemId"].">Remove</a></td>";
echo"</tr>";
}
// Increment the total cost of all items
$totalCost += ($row2["qty"] * $row2["itemPrice"]);
echo "<tr> <td colspan='2'> <a href='homestore.php'>Keep Shopping</a></td>";
echo "<td colspan='2'> <b>Total: SR".$totalCost."</b></td></tr>";
echo "</table>";}
break;
}}
case "show":
{
$totalCost =0;
$query = "select * from cart inner join items on cart.itemId = items.itemId";
$result = mysql_query($query);
?>
<table width="100%" border="1">
<?php while($row = mysql_fetch_array($result))
{
$totalCost += ($row["qty"] * $row["itemPrice"]);
?>
<tr>
<td><?php echo $row["itemName"]; ?></td>
<td>SR<?php echo $row["itemPrice"]; ?></td>
<td><a href="cart.php?action=show_update&id=<?php echo $row["itemId"]; ?>">edit</a></td>
<td><a href="cart.php?action=remove&id=<?php echo $row["itemId"]; ?>">Remove</a></td>
</tr>
<?php }
// Increment the total cost of all items
$totalCost += ($row["qty"] * $row["itemPrice"]);
$totalCost = $totalCost + ($row["qty"] * $row["itemPrice"]); ?>
<tr> <td colspan="2"> <a href="products.php">Keep Shopping</a></td>
<td colspan="2"> <b>Total: SR<?php echo $totalCost; ?></b></td></tr>
</table>
<?php break; }
}
?>
</body>
</html>
如果用户单击链接，则操作 =“添加”和产品 ID 将转换为 cart.php，问题是 $action 无法插入到 Switch 语句中，即使我已经回显了 $action 并且它打印添加 I不知道为什么它没有进入 switch statment 我也尝试回显 $id 并打印 2 这是正确的2 我想发疯，因为我整天在笔记本电脑上设置 2 并且它不工作。
在这里，我不与购物车的会话或用户发生冲突，这就是为什么在添加情况下我刚刚插入 1 作为 uid 的第一个值，如果它成功，我将添加会话。按下添加到卡后，它将直接转移到我们找到编辑和删除的展示案例，当然在展示案例中按删除它会将他转移到移除案例
如果他在展示案例中按下编辑链接，它将转移他到展示更新案例，他可以在其中编辑数量，如果 id 匹配 id 文本框将生成其他产品将没有文本框，默认数量将为 1 如果文本框生成保存链接它将出现改变他更新情况的情况，我们更新购物车表中的数量。
我只是想知道为什么$action不能进入 switch 语句？