为什么查询只删除最后一行？

Question

<?php
$query= mysqli_query($link, "SELECT * FROM Messages");
while ($row=mysqli_fetch_assoc($query)){
  $MID= $row['mesgID'];
?>
<br><br><br><center><caption><?php echo "The <strong>".$row['type']."</strong> ID: ".$row['mesgID']; ?></caption></center>
<center><table border='4'; style="border-color:darkblue;">
<tr>
    <td style="width:70%; text-align:left;"><?php echo "<strong>From: </strong>".$row['email']."<br><strong>About: </strong>".$row['areaCode']; ?></td>
</tr>
    <tr>
        <td style="width:70%; text-align:center;"><?php echo "<strong>Message content</strong><br><br>".$row['message']."<br>"; ?></td>
    </tr>
</table></center>

 <form action="ContactCleanersManagementStaffSide.php" method="post">
<center>
  <input class="button button3" type="submit" name="<?php echo $MID; ?>"value="DELETE" id="submit"/></center>
    </form>
<br><br>
<?php
}


if(isset($_POST[$MID])){

    $query = mysqli_query($link, "DELETE FROM Messages WHERE mesgID='$MID'");
}

    ?>

I create "delete" button with unique name for each button, but when i clicks any button -except the last button- it's not deleting, but when i click the lats button, it's deleted seccessfully.

Answer 1

Instead of using id as name attriute of button, i will ask you to create a hidden filed with name="mesgID" and value="<?php echo $row['mesgID']; ?>" like below:

<?php

    $query= mysqli_query($link, "SELECT * FROM Messages");
    while ($row=mysqli_fetch_assoc($query)){
?>
    <br>
    <br>
    <br>
    <center>
        <caption><?php echo "The <strong>".$row['type']."</strong> ID: ".$row['mesgID']; ?></caption>
    </center>
    <center>
        <table border='4'; style="border-color:darkblue;">
            <tr>
                <td style="width:70%; text-align:left;">
                    <?php echo "<strong>From: </strong>".$row['email']."<br><strong>About: </strong>".$row['areaCode']; ?>
                </td>
            </tr>
            <tr>
                <td style="width:70%; text-align:center;">
                    <?php echo "<strong>Message content</strong><br><br>".$row['message']."<br>"; ?>
                </td>
            </tr>
        </table>
    </center>

    <form method="post">
        <input type="hidden" name="mesgID" value="<?php echo $row['mesgID']; ?>">
        <center>
            <input class="button button3" type="submit" name="Delete" value="DELETE" id="submit"/>
        </center>
    </form>
    <br>
    <br>
<?php }

    if(isset($_POST['mesgID'])){
        $query=mysqli_query($link, "DELETE FROM Messages WHERE mesgID=".$_POST['mesgID']);
    }
?>

Note:- Current code is wide-open for SQL INJECTION so use prepared statements

Additional Note: A 'quick' fix [only] for SQL Injection is to force type casting to integer for numeric id values.

$query=mysqli_query($link, "DELETE FROM Messages WHERE mesgID=".(int)$_POST['mesgID']);

The above is NOT a replacement for leveling up to parameterised Queries.

References:-

mysqli::prepare

PDO::prepare