未定义的变量：在第61行的C：\ xampp \ htdocs \ xampp \ Test \ HRMS \ try \ search1.php中删除

时间：2012-01-13 06:17:34

标签： php mysql sql phpmyadmin

我在过去2小时内非常努力，但我无法理解。为什么我在DELETE中获取未定义的变量。请查看我的代码并帮助我。

我的主要目的是使用复选框一次删除多行。

当我尝试运行以下代码时，它会出现以下错误：

Undefined variable: delete in C:\xampp\htdocs\xampp\Test\HRMS\try\search1.php on line 61

但我已经按照以下方式使用它了：

<td colspan="5" align="center" bgcolor="#FFFFFF"><input name="delete" type="submit" id="delete" value="Delete"></td>

提前致谢。

我的php代码：

  <?php
  $host="localhost"; // Host name
  $username="a"; // Mysql username
  $password="a"; // Mysql password
  $db_name="b"; // Database name
  $tbl_name="emp_info"; // Table name

  // Connect to server and select databse.
  mysql_connect("$host", "$username", "$password")or die("cannot connect");
  mysql_select_db("$db_name")or die("cannot select DB");

  $sql="SELECT * FROM $tbl_name";
  $result=mysql_query($sql);

  $count=mysql_num_rows($result);

  ?>
  <table width="400" border="0" cellspacing="1" cellpadding="0">
  <tr>
  <td><form name="form1" method="post" action="">
  <table width="400" border="0" cellpadding="3" cellspacing="1" bgcolor="#CCCCCC">
  <tr>
  <td bgcolor="#FFFFFF">&nbsp;</td>
  <td colspan="4" bgcolor="#FFFFFF"><strong>Delete multiple rows in mysql</strong> </td>
  </tr>
  <tr>
  <td align="center" bgcolor="#FFFFFF">#</td>
  <td align="center" bgcolor="#FFFFFF"><strong>Id</strong></td>
  <td align="center" bgcolor="#FFFFFF"><strong>Name</strong></td>
  <td align="center" bgcolor="#FFFFFF"><strong>Password</strong></td>
  <td align="center" bgcolor="#FFFFFF"><strong>Address</strong></td>
  <td align="center" bgcolor="#FFFFFF"><strong>Source</strong></td>
  <td align="center" bgcolor="#FFFFFF"><strong>salary</strong></td>
  <td align="center" bgcolor="#FFFFFF"><strong>Zip</strong></td>
  <td align="center" bgcolor="#FFFFFF"><strong>Mobile</strong></td>
  <td align="center" bgcolor="#FFFFFF"><strong>Email</strong></td>
  </tr>
  <?php
  while($rows=mysql_fetch_array($result)){
  ?>
  <tr>
  <td align="center" bgcolor="#FFFFFF"><input name="checkbox[]" type="checkbox" id="checkbox[]" value="<? echo $rows['eid']; ?>"></td>
  <td bgcolor="#FFFFFF"><? echo $rows['eid']; ?></td>
  <td bgcolor="#FFFFFF"><? echo $rows['ename']; ?></td>
  <td bgcolor="#FFFFFF"><? echo $rows['password']; ?></td>
  <td bgcolor="#FFFFFF"><? echo $rows['address']; ?></td>
  <td bgcolor="#FFFFFF"><? echo $rows['source']; ?></td>
  <td bgcolor="#FFFFFF"><? echo $rows['salary']; ?></td>
  <td bgcolor="#FFFFFF"><? echo $rows['zip']; ?></td>
  <td bgcolor="#FFFFFF"><? echo $rows['mobile']; ?></td>
  <td bgcolor="#FFFFFF"><? echo $rows['email']; ?></td>
  </tr>
  <?php
  }
  ?>
  <tr>
  <td colspan="5" align="center" bgcolor="#FFFFFF"><input name="delete" type="submit" id="delete" value="Delete"></td>
  </tr>
  <?php
  // Check if delete button active, start this
  if($delete){
  for($i=0;$i<$count;$i++){
  $del_id = $checkbox[$i];
  $sql = "DELETE FROM $tbl_name WHERE eid='$del_id'";
  $result = mysql_query($sql);
  }

  // if successful redirect to search1.php
  if($result){
  echo "<meta http-equiv=\"refresh\" content=\"0;URL=search1.php\">";
  }
  }
  mysql_close();
  ?>
  </table>
  </form>
  </td>
  </tr>
  </table>

2 个答案:

答案 0 :(得分：3)

注册全局变量是关闭的（这很好）所以行

if($delete){

应该是

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

此外，您需要重新构建代码，因为当您有删除记录的发布请求时，绝对不需要对数据库进行选择查询。

这是您需要的完整代码。用这个替换你的。

<?php

error_reporting(E_ALL);

$host = "localhost"; // Host name
$username = "a"; // Mysql username
$password = "a"; // Mysql password
$db_name = "b"; // Database name
$tbl_name = "emp_info"; // Table name

// Connect to server and select databse.
mysql_connect("$host", "$username", "$password")or die("cannot connect");
mysql_select_db("$db_name")or die("cannot select DB");

// Delete records
if (isset($_POST['delete']))
{
    // Concatenate ids in a comma-separated string
    $ids = implode(',', $_POST['checkbox']);

    if (!empty($ids))
    {
        $sql = "DELETE FROM $tbl_name WHERE eid IN ($ids)";
        $result = mysql_query($sql) or die(mysql_error());
    }

    // Redirect back
    header('Location: search1.php');
    die();
}

// Select records
$sql = "SELECT * FROM $tbl_name";
$result = mysql_query($sql);

$count = mysql_num_rows($result);

?>
<table width="400" border="0" cellspacing="1" cellpadding="0">
    <tr>
        <td>
            <form name="form1" method="post" action="">
                <table width="400" border="0" cellpadding="3" cellspacing="1" bgcolor="#CCCCCC">
                    <tr>
                        <td bgcolor="#FFFFFF">&nbsp;</td>
                        <td colspan="4" bgcolor="#FFFFFF"><strong>Delete multiple rows in mysql</strong></td>
                    </tr>
                    <tr>
                        <td align="center" bgcolor="#FFFFFF">#</td>
                        <td align="center" bgcolor="#FFFFFF"><strong>Id</strong></td>
                        <td align="center" bgcolor="#FFFFFF"><strong>Name</strong></td>
                    </tr>
                    <?php while ($rows = mysql_fetch_array($result)) { ?>
                    <tr>
                        <td align="center" bgcolor="#FFFFFF">
                            <input name="checkbox[]" type="checkbox" id="checkbox[]"
                                   value="<?php echo $rows['eid']; ?>">
                        </td>
                        <td bgcolor="#FFFFFF"><?php echo $rows['eid']; ?></td>
                        <td bgcolor="#FFFFFF"><?php echo $rows['ename']; ?></td>
                    </tr>
                    <?php } ?>
                    <tr>
                        <td colspan="5" align="center" bgcolor="#FFFFFF">
                            <input name="delete" type="submit" id="delete" value="Delete">
                        </td>
                    </tr>
                </table>
            </form>
        </td>
    </tr>
</table>

答案 1 :(得分：0)

在从MySQL结果变量循环结果之前，总是必须确保它包含任何值：

if($total > 0)
{
    while ($rows = mysql_fetch_array($result))
    {
        //your code goes here
    }
}

您在这里遇到的另一个问题与previous question中的问题相同，未定义变量$ delete，根据您的代码，不清楚它的来源。

因此，如果$delete实际上是$_POST变量，那么您的if语句应如下所示：

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

另一个问题，$checkbox未定义。我建议您阅读有关filter_input方法的更多信息，因为它可以非常方便地清理用户提交的数据。

此外，您使用的是不正确的html标签，而不是：

<td align="center" bgcolor="#FFFFFF"><strong>Id</strong></td>

使用正确的TD标记对齐中心文本并使其变为粗体，bgcolor也应在CSS文件中定义。

<th bgcolor="#FFFFFF">Id</th>

您的最终代码应如下所示：

<?php
$host = "localhost"; // Host name
$username = "a"; // Mysql username
$password = "a"; // Mysql password
$db_name = "b"; // Database name
$tbl_name = "emp_info"; // Table name

// Connect to server and select databse.
mysql_connect("$host", "$username", "$password")or die("cannot connect");
mysql_select_db("$db_name")or die("cannot select DB");

// Make sure that delete action was called using
//$delete = isset($_POST['delete']);
//OR
//$delete = array_key_exists('delete', $_POST);
//OR
$delete = filter_input(INPUT_POST, 'delete');

$selected = filter_input(INPUT_POST, 'checkbox', FILTER_VALIDATE_INT, FILTER_REQUIRE_ARRAY);

if ($delete && !empty($selected))
{

    foreach ($selected as $id)
    {
        $sql = "DELETE FROM $tbl_name WHERE eid='$id'";

        $result = mysql_query($sql);
    }

    // if successful redirect to search1.php
    echo "<meta http-equiv=\"refresh\" content=\"0;URL=search1.php\">";
}

$sql = "SELECT * FROM $tbl_name";

$result = mysql_query($sql);

$count = mysql_num_rows($result);

?>


<form name="form1" method="post" action="">
    <table width="400" border="0" cellpadding="3" cellspacing="1" bgcolor="#CCCCCC">
        <tr>
            <th bgcolor="#FFFFFF">&nbsp;</th>
            <th colspan="9" bgcolor="#FFFFFF">Delete multiple rows in mysql</th>
        </tr>
        <tr>
            <th bgcolor="#FFFFFF">#</th>
            <th bgcolor="#FFFFFF">Id</th>
            <th bgcolor="#FFFFFF">Name</th>
            <th bgcolor="#FFFFFF">Password</th>
            <th bgcolor="#FFFFFF">Address</th>
            <th bgcolor="#FFFFFF">Source</th>
            <th bgcolor="#FFFFFF">salary</th>
            <th bgcolor="#FFFFFF">Zip</th>
            <th bgcolor="#FFFFFF">Mobile</th>
            <th bgcolor="#FFFFFF">Email</th>
        </tr>
        <?php
        if ($count)
        {
            while ($rows = mysql_fetch_array($result))
            {
                ?>
                <tr>
                    <td align="center" bgcolor="#FFFFFF">
                        <input name="checkbox[]" type="checkbox" id="checkbox" value="<?php echo $rows['eid']; ?>">
                    </td>
                    <td bgcolor="#FFFFFF"><?php echo $rows['eid']; ?></td>
                    <td bgcolor="#FFFFFF"><?php echo $rows['ename']; ?></td>
                    <td bgcolor="#FFFFFF"><?php echo $rows['password']; ?></td>
                    <td bgcolor="#FFFFFF"><?php echo $rows['address']; ?></td>
                    <td bgcolor="#FFFFFF"><?php echo $rows['source']; ?></td>
                    <td bgcolor="#FFFFFF"><?php echo $rows['salary']; ?></td>
                    <td bgcolor="#FFFFFF"><?php echo $rows['zip']; ?></td>
                    <td bgcolor="#FFFFFF"><?php echo $rows['mobile']; ?></td>
                    <td bgcolor="#FFFFFF"><?php echo $rows['email']; ?></td>
                </tr>
                <?php
            }
        }
        mysql_close();
        ?>
        <tr>
            <td colspan="10" align="center" bgcolor="#FFFFFF">
                <input name="delete" type="submit" id="delete" value="Delete">
            </td>
        </tr>
    </table>
</form>

请不要只是复制粘贴，阅读并尝试理解它。

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