我正在大学里学习网络开发，我对此练习有疑问。 “用户将能够将商品添加到购物车中，声明购买数量，然后继续购买商品。与此同时，库存将减少到底部。”我该怎么做？？？我的尝试代码已包含在下面。
<?php
session_start();
$connect = mysqli_connect("localhost", "root", "", "test");
if(isset($_POST["add_to_cart"]))
{
if(isset($_SESSION["shopping_cart"]))
{
$item_array_id = array_column($_SESSION["shopping_cart"], "item_id");
if(!in_array($_GET["id"], $item_array_id))
{
$count = count($_SESSION["shopping_cart"]);
$item_array = array(
'item_id' => $_GET["id"],
'item_name' => $_POST["hidden_name"],
'item_price' => $_POST["hidden_price"],
'item_quantity' => $_POST["quantity"]
);
$_SESSION["shopping_cart"][$count] = $item_array;
}
else
{
echo '<script>alert("Item Already Added")</script>';
echo '<script>window.location="shop.php"</script>';
}
}
else
{
$item_array = array(
'item_id' => $_GET["id"],
'item_name' => $_POST["hidden_name"],
'item_price' => $_POST["hidden_price"],
'item_quantity' => $_POST["quantity"]
);
$_SESSION["shopping_cart"][0] = $item_array;
}
}
if(isset($_GET["action"]))
{
if($_GET["action"] == "delete")
{
foreach($_SESSION["shopping_cart"] as $keys => $values)
{
if($values["item_id"] == $_GET["id"])
{
unset($_SESSION["shopping_cart"][$keys]);
echo '<script>alert("Item Removed")</script>';
echo '<script>window.location="shop.php"</script>';
}
}
}
}
?>
<?php
if(isset($_POST["submit_order"]))
{
echo "<script> alert('Your order has been placed!');</script>";
header('Refresh: 1; index.html');
}
?>
<!DOCTYPE html>
<html>
<head>
<title>SHOP</title>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.2.0/jquery.min.js"></script>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css" />
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>
</head>
<body>
<br />
<div class="container">
<br />
<br />
<br />
<br /><br />
<?php
$query = "SELECT * FROM items ORDER BY id ASC";
$result = mysqli_query($connect, $query);
if(mysqli_num_rows($result) > 0)
{
while($row = mysqli_fetch_array($result))
{
?>
<div class="col-md-4">
<form method="post" action="shop.php?action=add&id=<?php echo $row["id"]; ?>">
<div style="border:1px solid #333; background-color:#f1f1f1; border-radius:5px; padding:16px;" align="center">
<img src="imag/<?php echo $row["image"]; ?>" class="img-responsive" /><br />
<h4 class="text-info"><?php echo $row["name"]; ?></h4>
<h4 class="text-danger">$ <?php echo $row["price"]; ?></h4>
<input type="text" name="quantity" value="1" class="form-control" />
<input type="hidden" name="hidden_name" value="<?php echo $row["name"]; ?>" />
<input type="hidden" name="hidden_price" value="<?php echo $row["price"]; ?>" />
<input type="submit" name="add_to_cart" style="margin-top:5px;" class="btn btn-success" value="Add to Cart" />
</div>
</form>
</div>
<?php
}
}
?>
<div style="clear:both"></div>
<br />
<h3>Order Details</h3>
<div class="table-responsive">
<table class="table table-bordered">
<tr>
<th width="40%">Item Name</th>
<th width="10%">Quantity</th>
<th width="20%">Price</th>
<th width="15%">Total</th>
<th width="5%">Action</th>
</tr>
<?php
if(!empty($_SESSION["shopping_cart"]))
{
$total = 0;
foreach($_SESSION["shopping_cart"] as $keys => $values)
{
?>
<tr>
<td><?php echo $values["item_name"]; ?></td>
<td><?php echo $values["item_quantity"]; ?></td>
<td>$ <?php echo $values["item_price"]; ?></td>
<td>$ <?php echo number_format($values["item_quantity"] * $values["item_price"], 2);?></td>
<td><a href="shop.php?action=delete&id=<?php echo $values["item_id"]; ?>"><span class="text-danger">Remove</span></a></td>
</tr>
<?php
$total = $total + ($values["item_quantity"] * $values["item_price"]);
}
?>
<tr>
<td colspan="3" align="right">Total</td>
<td align="right">$ <?php echo number_format($total, 2); ?></td>
<td></td>
</tr>
<?php
}
?>
</table>
</div>
<form method="post" action="shop.php">
<div style="border:1px solid #333; background-color:#f1f1f1; border-radius:5px; padding:16px;" align="center">
<input type="submit" name="submit_order" style="margin-top:5px;" class="btn btn-success" value="Submit your order" />
</form>
</div>
</div>
<br />
</body>
</html>
<?php
?>