Undefined array key 'quantity' appears in C:\xampp\htdocs\login\cart-item.php
P粉549412038
2023-09-05 20:18:59
<p>I am following the tutorial video but there is no output table in the database. I followed every step in the video.I also tried initializing the quantity into a variable but it still doesn't work</p>
<pre class="brush:php;toolbar:false;"><?php
session_start();
$connect = mysqli_connect("localhost", "root", "", "login_sample_db");
if(isset($_POST['add_to_cart'])){
if(isset($_SESSION['cart'])){
$session_array_id = array_column($_SESSION['cart'], "id");
if(!in_array($_GET['id'], $session_array_id)){
$session_array = array(
'id' => $_GET['id'],
"name" => $_POST['name'],
"price" => $_POST['price'],
"quantity" => $_POST['quantity']
);
$_SESSION['cart'][] = $session_array;
}
}else{
$session_array = array(
'id' => $_GET['id'],
"name" => $_POST['name'],
"price" => $_POST['price'],
"quantity" => $_POST['quantity']
);
$_SESSION['cart'][] = $session_array;
}
}?>
<!DOCTYPE html>
<html>
<head>
<title>Products</title>
<link rel="stylesheet" type="text/css" href="styles.css">
<link rel="stylesheet" type="text/css" href="cart-item.css">
<style>
</style>
</head>
<body>
<div class="container-fluid">
<div class="col-md-12">
<div class="row">
<div class="col-md-6">
<h2 class="text-center">购物车数据</h2>
<div class="col-md-12">
<div class="row">
<?php
$query = "SELECT * FROM cart_item";
$result = mysqli_query($connect, $query);
while($row = mysqli_fetch_array($result)){
?>
<div class="col-md-4">
<form method="post" action="cart-item.php?id=<?= $row['id'] ?>">
<h5 class="text-center"><?= $row['name']; ?></h5>
<h5 class="text-center">$<?= number_format($row['price'], 2); ?></h5>
<input type="hidden" name="name" value="<?= $row['name'] ?>">
<input type="hidden" name="price" value="<?= $row['price'] ?>">
<input type="number" name="quantity" value="1" class="form-control">
<input type="submit" name="add_to_cart" class="btn btn-warning btn-block my-2" value="添加到购物车">
</form>
</div>
<?php
}
?>
</div>
</div>
</div>
<div class="col-md-6">
<h2 class="text-center">Selected items</h2>
<?php
$total = 0;
$output = "";
$output .= "
<table class='table table-bordered table-striped'>
<tr>
<th>ID</th>
<th>Product Name</th>
<th>Product price</th>
<th>Item quantity</th>
<th>Total Price</th>
<th>Operation</th>
</tr>
";
if(!empty($_SESSION['cart'])){
foreach($_SESSION['cart'] as $key => $value){
$output .= "
<tr>
<td>".$value['id']."</td>
<td>".$value['name']."</td>
<td>".$value['price']."</td>
<td>".$value['quantity']."</td>
<td>$".number_format($value['price'] * $value['quantity'])."</td>
<td>
<a href='cart-item.php?action=remove&id=".$value['id']."'>
<button class='btn btn-danger btn-block'>Remove</button>
</a>
</td>
</tr>
";
$total = $total $value['quantity'] * $value['price'];
}
$output .= "
<tr>
<td colspan='3'></td>
<td></b>Total Price</b></td>
<td>".number_format($total, 2)."</td>
<td>
<a href='cart-item.php?action=clearall'>
<button class='btn btn-warning btn-block'>Clear</button>
</a>
</td>
</tr>
";
}echo $output;
?>
</div>
</div>
</div>
</div>
</body>
</html></pre>
<p>I checked the quantity array key multiple times and compared with the video, same as in the video. Is there anything else I should try? The table in the database also does not contain quantities</p>
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
I'll comment if I know more details, but are you sure your database schema and table definitions are correct? Where is your
INSERT/UPDATElogic? Where did the error occur and what exactly was it? Please provide more information.