在php中如何“挨个”删除数据库信息？

functions.php

$conn = mysqli_connect("localhost:3305","root","1234","dj"); //connect database
function getRealIpUser(){

    switch(true){

        case(!empty($_SERVER['HTTP_X_REAL_IP'])) : return $_SERVER['HTTP_X_REAL_IP'];
        case(!empty($_SERVER['HTTP_CLIENT_IP'])) : return $_SERVER['HTTP_CLIENT_IP'];
        case(!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) : return $_SERVER['HTTP_X_FORWARDED_FOR'];

        default : return $_SERVER['REMOTE_ADDR'];

    }

}

cart.php

<include ("functions.php");> 
<div class="shopping-cart">
                <h6>My Cart</h6>
                <hr>
                <?php

                $ip_add = getRealIpUser(); //getRealIpuser from functions.php

                $select_cart = "select * from cart where ip_add='$ip_add'";

                $run_cart = mysqli_query($conn,$select_cart);

                while($row_cart = mysqli_fetch_array($run_cart)){

                    $pro_id = $row_cart['p_id'];

                    $pro_size = $row_cart['size'];

                    $pro_quantity = $row_cart['quantity'];

                  ?>

                        <form action="cart.php" method="post" class="cart-items">
                            <div class="border rounded">
                                <div class="row bg-white">
                                    <div class="col-md-6">
                                        <button type="submit" class="btn btn-warning">Save for Later</button>
                                        <button type="submit" id="<?php echo $pro_id;?>" class="btn btn-danger mx-2" name="remove">Remove</button>
                                    </div>

                                </div>
                            </div>
                        </form>

然后下面是我的错误的代码：

<?php

    global $conn;
    if(isset($_POST['remove'])){

            $delete_product = "delete from cart where p_id='$pro_id'";

            $run_delete = mysqli_query($conn,$delete_product);

            if($run_delete){

                echo "<script>window.open('cart.php','_self')</script>";

            }

}

?>

您需要遍历购物车，并逐个删除相应的产品。在您的cart.php文件中，while循环中的每个表单都应该具有唯一的ID属性，以与每个产品的ID对应。您的删除代码没有传递产品ID，因此无法删除正确的产品。以下是您可以尝试的更新代码：

<?php

if(isset($_POST['remove'])){
    
    global $conn;
    
    $pro_id = $_POST['remove'];
    $delete_product = "delete from cart where p_id='$pro_id'";
    $run_delete = mysqli_query($conn,$delete_product);

    if($run_delete){
        echo "<script>window.open('cart.php','_self')</script>";
    }

}

?>

请注意，您仍然需要在while循环中的每个表单元素上将产品ID作为ID属性传递，例如：

<button type="submit" id="<?php echo $pro_id;?>" class="btn btn-danger mx-2" name="remove">Remove</button>