php - 删除按钮不起作用

我正在用SQL语句学习PHP，但是在尝试创建删除按钮时遇到了问题。

问题是当我按下“删除”按钮时什么也没发生。
查询运行正常，它从循环中获取正确的用户标识。

<?php
        require_once 'db_connect.php';

        $select = "SELECT * FROM Users";
        $result = mysqli_query($dbc, $select) or die('could not query database');


        while ($row = mysqli_fetch_assoc($result)) {

            echo '
            <tr>
                <td>' . $row['userid'] . '</td>
                <td>' . $row['fnamn'] . ' ' . $row['enamn'] . '</td>
                <td>' . $row['username'] . '</td>
                <td>' . $row['email'] . '</td>
                    <td>' . '<form action="" method="post">
                            <input type="button" name="delete" value="Radera" />
                        </form>' . '</td>

            </tr>';

            if(isset($_POST['delete'])) {

                $userid = $row['userid'];

                $delete = "DELETE FROM Users WHERE userid = '$userid' ";
                $result = mysqli_query($dbc, $delete) or die('could not query database');
            }
        }

        mysqli_close($dbc);
        ?>

最佳答案

你需要：


将您的if (isset($_POST['delete']))语句放在外面
在while循环之前。
通过某种方式知道要删除的行（也许带有
隐藏的输入）。


像这样：

<?php
require_once 'db_connect.php';

if(isset($_POST['delete']) && isset($_POST['user_id'])) {
    $userid = $_POST['user_id'];

    $delete = "DELETE FROM Users WHERE userid = '$userid' ";
    $result = mysqli_query($dbc, $delete) or die('could not query database');
}

$select = "SELECT * FROM Users";
$result = mysqli_query($dbc, $select) or die('could not query database');

while ($row = mysqli_fetch_assoc($result)) {
    echo '
    <tr>
        <td>' . $row['userid'] . '</td>
        <td>' . $row['fnamn'] . ' ' . $row['enamn'] . '</td>
        <td>' . $row['username'] . '</td>
        <td>' . $row['email'] . '</td>
        <td>' . '<form action="" method="post">
            <input type="hidden" name="user_id" id="user_id" value="'.$row['userid'].'" />
            <input type="submit" name="delete" id="delete" value="Radera" />
        </form>' . '</td>
    </tr>';
}

mysqli_close($dbc);
?>

我不建议您像上述一样直接在查询中插入$_POST['user_id']；您将需要阅读准备好的语句

关于php - 删除按钮不起作用，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/14167535/