Question

我试图使用DELETE语句删除一行。但是，由于我是PHP的新手，我不知道自己做错了什么。我的代码不断回显错误信息，我不知道如何让它工作。

感谢。

<!DOCTYPE html>
<html lang="en">
<head>
    <title>peak | delete student</title>
<meta charset="UTF-8">
</head>
<body>
<div style="margin-left: 300px;">
<form method="post">
    <input type="text" name="student_number" placeholder="student number" 
id="student number"><br>
    <input type="submit" value="delete">
</form>
</div>

<?php 

include 'config.php';

$id = ''; 
if( isset( $_GET['id'])) {
$id = $_GET['id']; 
} 

    if(isset($_POST["student_number"])) {

    $sql= "DELETE FROM `Students` (`first name`,`last name`,`student 
number`,`gender`,`address`,`phone number`,`mark`) WHERE `student number`='".$id."'";

    $result = mysqli_query($conn,$sql);

    if($result){echo "student deleted successfully!";}

    else {echo "error. unable to delete student.";}

    }
 ?>
 </body>
 </html>

Answer 1

您可以使用这种方式删除记录。这里，不需要在删除查询中包含字段名称。

<?php
$con=mysqli_connect("localhost","root","","test");
if(!$con)
die("could not connect:".mysqli_error());
else
echo "connected<br>";

if(isset($_GET["student_number"])) 
{
$id = $_GET["student_number"]; 

    $sel="select * from students where student_number='$id'";
    $result=mysqli_query($con,$sel);
    $row=mysqli_fetch_assoc($result);
    $checkid=$row['student_number'];

    if($id==$checkid)
    {
    $sql="delete from students where student_number='$id'";

    $result=mysqli_query($con,$sql);
    if($result)
    {
    echo "student deleted successfully!";
    }
    else 
    {
    echo "error. unable to delete student.";
    }

}
else
{
    echo "no record found";
}
}
?>

<html>
<head>
    <title>peak | delete student</title>
</head>
<body>
        <div style="margin-left: 300px;">
        <form method="get" action="">
            <input type="text" name="student_number" placeholder="student number" 
            id="student number"><br>
            <input type="submit" name="delete" value="delete">
        </form>
        </div>

</body>
</html>

Answer 2

我想出了如何删除。我正在使用id和post，所以我删除了id方法，只使用了帖子

<!DOCTYPE html>
 <html lang="en">
 <head>
<title>peak | delete student</title>
<meta charset="UTF-8">
</head>
<body>
<div style="margin-left: 300px;">
<form method="post">
    <input type="text" name="student_number" placeholder="student number" 
id="student number"><br>
<input type="submit" value="delete">
</form>
</div>

<?php 

 include 'config.php';


    if(isset($_POST["student_number"])) {

    $sql= "DELETE FROM `Students` WHERE `student number`=".$_POST["student_number"];

    $result = mysqli_query($conn,$sql);

    if($result){echo "success!";}

    else {echo "error.";}

    }
?>
</body>
</html>

试图从MySQL数据库+ PHP中删除记录。但保持获取错误消息

2 个答案: