使用 PHP & JavaScript 从数据库中删除数据

Question

我正在处理 PHP 文件。我正在尝试制作一个 table 来显示数据库中的产品列表。还将有一个用于删除任何产品的按钮。我使用 javascript 从数据库中删除产品。我已经写了代码，没有发现任何错误。当我点击删除按钮时，它会显示确认框，但不会删除产品。这是代码：

<?php

$con=mysql_connect("localhost","root","");
mysql_select_db("grocery_shop",$con);

error_reporting(E_ALL^E_NOTICE);
session_start();


    $sql = mysql_query("select * from products");


if($_GET['did']){
    mysql_query("delete from products where product_id='$_GET[did]'");
    header("Location: product.php");
}

?>
<table border="1px" style="width:100%">
    <tr>
    <th>Serial No</th>
    <th>Product Name</th>       
    <th>Product Type</th>
    <th>Quantity</th>
    <th>Price</th>
    <th>Delete Product</th>
  </tr>
    <tr>
        <td></td>
        <td></td>
        <td></td>
        <td></td>
        <td></td>
        <td></td>
    </tr>

    <?php
    $i=1;
    while ($u = mysql_fetch_array($sql)) {
        ?>
        <tr>
            <td><?php echo $i; ?></td>
            <td><?php echo $u['product_name'];?></td>
            <td><?php echo $u['product_type'];?></td>
            <td><?php echo $u['quantity'];?></td>
            <td><?php echo $u['price'];?></td>
            <td><?php echo "<a href=\"javascript:delproduct(id=$u[product_id])\">Delete</a>";?></td>

        </tr>
        <?php
    $i++;
    }
    ?>

    <script>
    function delproduct(id){
        var msg = confirm("Are you sure you want to delete this product?");

    if (msg) {
        window.location = "product.php?did="+product_id;
    }
    }
    </script>
</table>

Answer 1

你忘记了 $_GET 中 did 的 ''[did]:

mysql_query("delete from products where product_id='{$_GET['did']}'");

此外，正如@chris85 指出的那样，直接使用 $_GET 或 $_POST 不是一个好主意，请记住在查询中使用它们之前先清理这些值。

$did = filter_input(INPUT_GET, 'did', FILTER_SANITIZE_NUMBER_INT);
mysql_query("delete from products where product_id={$did}");

Answer 2

您应该尝试：delproduct($u[product_id]) 而不是 delproduct(id=$u[product_id ])

mysql_query("delete from products where product_id='".$_GET['did']."'");

while ($u = mysql_fetch_array($sql)) {
        ?>
        <tr>
            <td><?php echo $i; ?></td>
            <td><?php echo $u['product_name'];?></td>
            <td><?php echo $u['product_type'];?></td>
            <td><?php echo $u['quantity'];?></td>
            <td><?php echo $u['price'];?></td>
            <td><?php echo "<a href=\"javascript:delproduct($u[product_id])\">Delete</a>";?></td>

        </tr>
        <?php
    $i++;
    }

Answer 3

  <?php

 $con=mysql_connect("localhost","root","");
 mysql_select_db("grocery_shop",$con);

 error_reporting(E_ALL^E_NOTICE);
session_start();


$sql = mysql_query("select * from products");


if($_GET['did']){
mysql_query("delete from products where product_id='$_GET[did]'");
header("Location: product.php");
}

?>
<table border="1px" style="width:100%">
<tr>
<th>Serial No</th>
<th>Product Name</th>       
<th>Product Type</th>
<th>Quantity</th>
<th>Price</th>
<th>Delete Product</th>
 </tr>
   <tr>
    <td></td>
    <td></td>
    <td></td>
    <td></td>
    <td></td>
    <td></td>
</tr>

<?php
$i=1;
while ($u = mysql_fetch_array($sql)) {
    ?>
    <tr>
        <td><?php echo $i; ?></td>
        <td><?php echo $u['product_name'];?></td>
        <td><?php echo $u['product_type'];?></td>
        <td><?php echo $u['quantity'];?></td>
        <td><?php echo $u['price'];?></td>
        <td><?php echo "<a href=\"javascript:delproduct(".$u[product_id].")\">Delete</a>";?></td>

    </tr>
    <?php
     $i++;
     }
    ?>

<script>
function delproduct(id){
     var product_id = id;
    var msg = confirm("Are you sure you want to delete this product?");

   if (msg) {
      window.location = "product.php?did="+product_id;
  }
  }
   </script>
</table>

Answer 4

问题出在你的javascript，product_id不存在

   if (msg) {
        window.location = "product.php?did="+id;
    }

出于调试目的，请尝试将其替换为您的代码，并让我们知道您收到的错误消息。

if($_GET['did']){
    mysql_query("delete from products where product_id='".$_GET['did']."'");
    echo "delete from products where product_id='".$_GET['did']."'";
    echo mysql_errno() . ": " . mysql_error() ;    
    die();
    //header("Location: product.php");
}

此外还尝试运行不带单引号的查询，我假设 product_id 是一个整数。

所以mysql_query("delete from products where product_id=".$_GET['did']);

使用 PHP & JavaScript 从数据库中删除数据

Delete data from database using PHP & JavaScript

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