PHP中如何在页面间传递动态数据库值并通过mail()发送？

Hey there! Let's break down why your cart details aren't making it to the email and fix it step by step.

The Core Problems #

1. Wrong Data Source in Page 1: You're trying to save $_POST['pID'], $_POST['pName'] etc. to the session, but when you add a product to the cart, you're using a GET request ($_GET['pID']). Those $_POST variables are empty, so nothing gets stored. Worse, even if they worked, your cart can have multiple items—storing single variables won't capture all products.
2. Incorrect Data Access in Page 2: You're trying to pull single session variables ($_SESSION['pID']), but your actual cart data lives in $_SESSION['cart'] (the array you built with the obj class).

Step 1: Clean Up Page 1 (cart.php) #

First, delete these lines from page 1—they're not doing anything useful and are based on incorrect input:

$_SESSION['pID'] = $_POST['pID'];
$_SESSION['pName'] = $_POST['pName'];
$_SESSION['pPrice'] = $_POST['pPrice'];
$_SESSION['qty'] = $_POST['qty'];

Your $_SESSION['cart'] array already holds all the cart items, so we don't need these single variables.

Step 2: Fix Page 2 (checkout.php) #

We need to loop through the $_SESSION['cart'] array to build the full cart details for the email. Here's the corrected code:

<?php
session_start();
require 'obj.php';
include("adminarea/includes/DBcon.php");

// First, check if the cart exists and isn't empty
if(!isset($_SESSION['cart']) || count($_SESSION['cart']) === 0){
    echo "<script> 
            alert('Your cart is empty!');
            window.location.href='cart.php';
          </script>";
    exit; // Stop execution if cart is empty
}

$to = "techologyy@gmail.com";
$subject = "Purchase Details:";

// Build the message by looping through the cart
$message = "Thank you for your purchase!\n\n";
$message .= "Your Cart Details:\n";
$message .= "------------------------\n";

$total = 0;
$cart = $_SESSION['cart'];
foreach($cart as $item){
    $subtotal = $item->pPrice * $item->qty;
    $total += $subtotal;
    // Add each item to the message
    $message .= "Product ID: " . $item->pID . "\n";
    $message .= "Product Name: " . $item->pName . "\n";
    $message .= "Price: €" . $item->pPrice . "\n";
    $message .= "Quantity: " . $item->qty . "\n";
    $message .= "Subtotal: €" . $subtotal . "\n\n";
}

// Add the final total
$message .= "------------------------\n";
$message .= "Total Amount: €" . $total;

$headers = 'From: techologyy@gmail.com' . "\r\n";

// Send the email
if(mail($to, $subject, $message, $headers)){
    // Clear the cart after successful checkout
    unset($_SESSION['cart']);
    echo "<script> 
            alert('The checkout has been done successfully! Thank you');
            window.location.href='index.php';
          </script>";
} else {
    echo "<script> 
            alert('Oops! There was an issue sending your order confirmation.');
            window.location.href='cart.php';
          </script>";
}
?>

Key Improvements in Page 2: #

• Cart Validation: Checks if the cart exists and has items before proceeding.
• Loop Through Cart Items: Uses foreach to iterate over every item in $_SESSION['cart'], so all products are included in the email.
• Proper Message Formatting: Builds a readable email with item details and a final total.
• Cart Cleanup: Clears the session cart after successful checkout (good practice for user experience).
• Error Handling: Checks if the email sent successfully and gives appropriate feedback.

Quick Security Note (For Future Improvement) #

Right now, your page 1 uses $_GET['pID'] directly in a MySQL query:

$res = mysqli_query($connection, 'select * from product where pID='.$_GET['pID']);

This is vulnerable to SQL injection. You should use prepared statements instead. Here's how to fix that line:

$stmt = mysqli_prepare($connection, "select * from product where pID = ?");
mysqli_stmt_bind_param($stmt, "i", $_GET['pID']);
mysqli_stmt_execute($stmt);
$res = mysqli_stmt_get_result($stmt);
$prod = mysqli_fetch_object($res);

This keeps your database safe from malicious input.

内容的提问来源于stack exchange，提问作者Redent