PHP/MYSQL: 删除的行在重新加载后仍显示在我的页面中

Question

我在 Raspberry Pi 上的一个简单网络服务器上工作，显示 MySQL table 有两个按钮：一个（切换）反转布尔值，一个（删除）从 table 中删除整行。

基本上，我所做的是 MySQL table 上的 while 循环，其中我：1：在表单中显示行和按钮，以及 2：检查按钮是否已被点击，如果是，我将查询发送到数据库并重新加载页面。

我的问题很简单：当我点击 "switch" 按钮时，查询被发送，页面被刷新，值被正确修改（页面显示值，因为它在数据库）。但是，当我单击另一个按钮 "delete" 时，页面重新加载后，该行仍出现在 table 中。只有当我手动重新加载页面时，该行才会消失。

我已经尝试过的： 1：在手动刷新之前检查该行是否已从数据库中删除：完成，并且该行已正确删除。 2：在 MySQL 查询后等待 500 毫秒，然后重新加载页面：完成，即使我等待 500 毫秒，当页面重新加载时仍然有删除的行。

这是完整的代码，MySQL 查询在最后：

<form action="logout.php" method="post">
<input type="submit" name="logout" value="logout">
</form>
<b>Alarm Monitoring</b>

<p>Sensors state table. Clicking on "Switch state" will switch the field "state" of the associated mote. </p>
<p>State 1 means that the mote is active, the alarm will be activated if the mote is moved or if someone is detected.</p>
<p>State 0 means that the mote is inactive, the alarm will NOT be activated if the mote is moved or if someone is detected.</p>


<?php
$servername="localhost";
$username="root";
$password="patate";
$dbname="testbase";
$table="matable";

$conn = new mysqli($servername,$username,$password,$dbname);
if ($conn->connect_error) {
        echo "kaput";
        die("Connection failed: " . $conn->connect_error);
}

$sql="SELECT * FROM $table;";
$result=$conn->query($sql); ?>


<table border=0>
    <tr>
        <td>

                <table border=1>
                    <tr>
                        <td width=150>ID</td>
                        <td width=150>Date</td>                        
                        <td width=300>PIR</td>  
                        <td width=150>Accel</td>
                        <td width=100>State</td>
                        <td width=150>Switch</td>
                        <td width=150>Delete</td>
                    </tr>
         <?php
   while($row = $result->fetch_assoc()) : ?>

                    <tr>
                        <td><?php echo $row['id']; ?></td>
                        <td><?php echo $row['date']; ?></td>
                        <td><?php echo $row['pir']; ?></td>
                        <td><?php echo $row['accel']; ?></td>
                        <td><?php echo $row['state']; ?></td>
                        <form name="form1" method="post" action=''>
                        <td><?php echo "<input name='Switch' type='submit' id='Switch' value='Switch state ".$row['id']."'>"; ?></td>
                        <td><?php echo "<input name='Delete' type='submit' id='Delete' value='Delete mote ".$row['id']."'>"; ?></td>
                        </form>
                    </tr>    
        <?php
if($_REQUEST['Delete']=='Delete mote ' . $row['id']) {
   {
        $sql3="DELETE FROM $table WHERE id=".$row['id'].";";
        $result3=$conn->query($sql3);
        header('Location: table.php');
    }
}

if($_REQUEST['Switch']=='Switch state ' . $row['id']) {
    {
        if($row['state']=='1')
        {
                $sql2="UPDATE $table SET state='0' WHERE id=".$row['id'].";";
        }
        else
        {      
                $sql2="UPDATE $table SET state='1' WHERE id=".$row['id'].";";
        }

        $result2=$conn->query($sql2);
        header('Location: table.php');
    }
}

?>

 <?php endwhile; ?>    
</table>            

</table>
</td>
</tr>
</table>

也许有人以前见过这个问题？

Answer 1

只需尝试在删除查询之后但在重定向之前清理结果数组，方法是：unset($row); 并通过启动清理 $result：$result='';

修改代码如下，在上面两行和下面两行添加四行注释：

    <form action="logout.php" method="post">
<input type="submit" name="logout" value="logout">
</form>
<b>Alarm Monitoring</b>

<p>Sensors state table. Clicking on "Switch state" will switch the field "state" of the associated mote. </p>
<p>State 1 means that the mote is active, the alarm will be activated if the mote is moved or if someone is detected.</p>
<p>State 0 means that the mote is inactive, the alarm will NOT be activated if the mote is moved or if someone is detected.</p>


<?php
$servername="localhost";
$username="root";
$password="patate";
$dbname="testbase";
$table="matable";

$conn = new mysqli($servername,$username,$password,$dbname);
if ($conn->connect_error) {
        echo "kaput";
        die("Connection failed: " . $conn->connect_error);
}
$row=array();                     //Initialize the empty array (By shashi).
$result='';                       //Initialize the empty result var (By shashi).

$sql="SELECT * FROM $table;";
$result=$conn->query($sql); ?>


<table border=0>
    <tr>
        <td>

                <table border=1>
                    <tr>
                        <td width=150>ID</td>
                        <td width=150>Date</td>                        
                        <td width=300>PIR</td>  
                        <td width=150>Accel</td>
                        <td width=100>State</td>
                        <td width=150>Switch</td>
                        <td width=150>Delete</td>
                    </tr>
         <?php
   while($row = $result->fetch_assoc()) : ?>

                    <tr>
                        <td><?php echo $row['id']; ?></td>
                        <td><?php echo $row['date']; ?></td>
                        <td><?php echo $row['pir']; ?></td>
                        <td><?php echo $row['accel']; ?></td>
                        <td><?php echo $row['state']; ?></td>
                        <form name="form1" method="post" action=''>
                        <td><?php echo "<input name='Switch' type='submit' id='Switch' value='Switch state ".$row['id']."'>"; ?></td>
                        <td><?php echo "<input name='Delete' type='submit' id='Delete' value='Delete mote ".$row['id']."'>"; ?></td>
                        </form>
                    </tr>    
        <?php
if($_REQUEST['Delete']=='Delete mote ' . $row['id']) {
   {
        $sql3="DELETE FROM $table WHERE id=".$row['id'].";";
        $result3=$conn->query($sql3);
        unset($row);                  //Clear the array (By shashi).
        result='';                    //Clear result Var (By shashi).
        header('Location: table.php');
    }
}

if($_REQUEST['Switch']=='Switch state ' . $row['id']) {
    {
        if($row['state']=='1')
        {
                $sql2="UPDATE $table SET state='0' WHERE id=".$row['id'].";";
        }
        else
        {      
                $sql2="UPDATE $table SET state='1' WHERE id=".$row['id'].";";
        }

        $result2=$conn->query($sql2);
        header('Location: table.php');
    }
}

?>

 <?php endwhile; ?>    
</table>            

</table>
</td>
</tr>
</table>

Answer 2

$sql="SELECT * FROM $table;"

应该在

之后

$sql3="DELETE FROM $table WHERE id=".$row['id'].";";

以及更新等其他操作...

看起来它已被删除，但您看到的是旧数据:)

<?php
    $servername="localhost";
    $username="root";
    $password="patate";
    $dbname="testbase";
    $table="matable";

    $conn = new mysqli($servername,$username,$password,$dbname);
    if ($conn->connect_error) {
            echo "kaput";
            die("Connection failed: " . $conn->connect_error);
    }

if($_REQUEST['Delete']) {
   {
        $sql3="DELETE FROM $table WHERE id=".(int)$_REQUEST['Delete'].";";
        $result3=$conn->query($sql3);

    }
}

if($_REQUEST['Switch']) {
    {

        $sql2="UPDATE $table SET state= IF (`state`, 0, 1) WHERE id=".(int)$_REQUEST['Switch'].";";


        $result2=$conn->query($sql2);

    }
}


    $sql="SELECT * FROM $table;";
    $result=$conn->query($sql); ?>

 <form action="logout.php" method="post">
<input type="submit" name="logout" value="logout">
</form>
<b>Alarm Monitoring</b>

<p>Sensors state table. Clicking on "Switch state" will switch the field "state" of the associated mote. </p>
<p>State 1 means that the mote is active, the alarm will be activated if the mote is moved or if someone is detected.</p>
<p>State 0 means that the mote is inactive, the alarm will NOT be activated if the mote is moved or if someone is detected.</p>





<table border=0>
    <tr>
        <td>

                <table border=1>
                    <tr>
                        <td width=150>ID</td>
                        <td width=150>Date</td>                        
                        <td width=300>PIR</td>  
                        <td width=150>Accel</td>
                        <td width=100>State</td>
                        <td width=150>Switch</td>
                        <td width=150>Delete</td>
                    </tr>
         <?php
   while($row = $result->fetch_assoc()) : ?>

                    <tr>
                        <td><?php echo $row['id']; ?></td>
                        <td><?php echo $row['date']; ?></td>
                        <td><?php echo $row['pir']; ?></td>
                        <td><?php echo $row['accel']; ?></td>
                        <td><?php echo $row['state']; ?></td>
                        <form name="form1" method="post" action=''>
                        <td><?php echo "<input name='Switch' type='submit' id='Switch' value='".$row['id']."'>"; ?></td>
                        <td><?php echo "<input name='Delete' type='submit' id='Delete' value='".$row['id']."'>"; ?></td>
                        </form>
                    </tr>    


 <?php endwhile; ?>    
</table>            

</table>
</td>
</tr>
</table>

请不要在这种情况下在 WHILE 循环中使用某些 SQL 查询

Answer 3

删除后，您指示浏览器重新加载页面：

header('Location: table.php');

但是，您无法在开始发送数据后发送 HTTP headers。您可能会在 table 下方某处看到一条错误消息，指出 "headers already sent".

您需要将页面内容的输出移动到上次使用 header() 函数修改响应 headers 之后，或者使用 output buffering.

Answer 4

您遇到重定向问题。检查此 link 以了解有关 redirect

的更多信息

在继续之前，请备份您的代码。

要解决您的问题，您必须将 <?php endwhile; ?> 移到

之后

</form>
</tr>

然后在表单名称后添加隐藏的输入"Delete"

<td>
<?php echo "<input name='Switch' type='submit' id='Switch' value='Switch state ".$row['id']."'>"; ?></td>
<td><?php echo "<input name='Delete' type='submit' id='Delete' value='Delete mote ".$row['id']."'>"; ?></td>
<input name='id' type='hidden' value="<?php echo $row['id']; ?>">
<input name='state' type='hidden' value="<?php echo $row['state']; ?>">

最后一个替换为：

<?php
if($_REQUEST['Delete']=='Delete mote ' . $row['id']) {
   {
        $sql3="DELETE FROM $table WHERE id=".$row['id'].";";
        $result3=$conn->query($sql3);
        header('Location: table.php');
    }
}

if($_REQUEST['Switch']=='Switch state ' . $row['id']) {
    {
        if($row['state']=='1')
        {
                $sql2="UPDATE $table SET state='0' WHERE id=".$row['id'].";";
        }
        else
        {      
                $sql2="UPDATE $table SET state='1' WHERE id=".$row['id'].";";
        }

        $result2=$conn->query($sql2);
        header('Location: table.php');
    }
}

?>

有了这个

<?php

        if (!empty($_REQUEST['Delete']) && !empty($_REQUEST['id']))
        {
            $sql3="DELETE FROM $table WHERE id=".$_REQUEST['id'].";";
            $result3=$conn->query($sql3);
            echo '<script> location.replace("index.php"); </script>';
        }

        if (!empty($_REQUEST['Switch']) && !empty($_REQUEST['id']) && isset($_REQUEST['state']))
        {
            var_dump($_REQUEST['Switch']);

            if($_REQUEST['state'] == '1')
            {
                    $sql2="UPDATE $table SET state='0' WHERE id=".$_REQUEST['id'].";";
            }
            else
            {      
                    $sql2="UPDATE $table SET state='1' WHERE id=".$_REQUEST['id'].";";
            }

            $result2=$conn->query($sql2);

            echo '<script> location.replace("index.php"); </script>';
        }
    ?>

我并不是说这是好的解决方案。但它会解决您的问题，直到您找到最佳解决方案。

Answer 5

这是一个很简单的问题，因为我遇到过他们，问题是SQL语句，你需要看看MYSQL，所以我解决了这个例子：

DELETE FROM `reyler` WHERE `reyler`.`id`=".$id_post1 ."";

你需要这个符号 => `` 它不是这个 " 或这个 '

其次你可以从 mysql 和 mysql 中删除，然后再删除 window 和 sql 语句，你可以从那里复制正确的语句，这与你的关联您的主机或 xampp 服务器中的数据库，我认为会对您有所帮助。))

PHP/MYSQL: 删除的行在重新加载后仍显示在我的页面中

PHP/MYSQL: A removed row is still displayed in my page after a reload

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apache2

raspberry-pi