使用 GET 的未定义索引

Undefined index with GET

while($row=mysqli_fetch_assoc($result)){                        
echo "<tr>";
echo ('<td>'.$row['idNo'].'</td>');
echo ('<td>'.$row['FirstName'].'</td>');
echo ('<td>'.$row['LogId'].'</td>');
echo ('<td>'.$row['PassCode'].'</td>');                  
echo '<td><a href="edit.php?id=' . $row['idNo'] . '">Edit</a></td>';                    
echo '<td><a href="delete_contestant.php?id=' . $row['idNo'] . '">Delete</a></td>';                   
echo("</tr>");}

delete_contestant.php 个页面的代码如下。但是当我试图删除一个项目时

shows Undefined index: idNo in Line 3

我什至尝试打印 $_GET['idNo'] 但它不起作用。

<?php
include('mysql_connect.php');
echo $_GET['idNo'];
if(isset($_GET['idNo']))
{
    $id=$_GET['idNo'];
    $sql="DELETE FROM addContestant WHERE idNo=$id";
    if(mysqli_query($conn,$sql))
    {
        echo "Item deleted";

    }
    else
        echo "There was a problem".mysqli_error($conn);
}
?>

您没有名为 idNoGET 参数,它是 id

echo '<td><a href="edit.php?id=' /* <<<< id, not idNo  */. $row['idNo'] . '">Edit</a></td>';                    

将您的代码更改为

echo $_GET['id'];
if(isset($_GET['id']))
{
    $id=$_GET['id'];
    //  ......

它应该可以工作。