Question

我是新来的，我面临着过滤数据而不在页面上显示的问题。我收到错误请帮助我。抱歉英语不好。

错误：

注意：未定义的变量：search_result in   /storage/ssd3/688/2645688/public_html/test.php在线

警告：mysqli_fetch_array（）期望参数1为mysqli_result，   在/storage/ssd3/688/2645688/public_html/test.php中给出的null

<?php
if(isset($_POST['submit']))
{
    $valueToSearch = $_POST['search'];

$query = "SELECT * FROM `login` WHERE CONCAT(`id`, `username`, `password`) LIKE '%".$valueToSearch."%'";
    $search_result = filterTable($query);
    
}

function filterTable($query)
{

$connect= mysqli_connect("localhost","root","","cable");
$filter_Result = mysqli_query($connect, $query);
    return $filter_Result;
}

?>
<form action="test.php" method="POST"> 
<div class="container">
	<div class="row">
        <br><br><div class="search">
<input type="text" name="search" class="form-control input-sm" maxlength="64" placeholder="Search" />
 <button type="submit" name="submit" class="btn btn-primary btn-sm">Search</button>
</div>
	</div>
</div>
</br></br>
</form>

<table>
                <tr>
                    <th>Id<br></th>
                    <th>Username:</th>
                    <th>Password</th>
                   </tr>
                                          <?php while($row = mysqli_fetch_array($search_result)):?>

                <tr>
                    <td><?php echo $row['id'];?><br></td>
                    <td><?php echo $row['username'];?></td>
                    <td><?php echo $row['password'];?></td>
                    
                </tr>
                <?php endwhile;?>
            </table>

Answer 1

您收到错误是因为当网页加载if(isset($_POST['submit']))为false时，$search_result = filterTable($query);不会执行，因此mysqli_fetch_array会获得NULL。

解决方案很简单，我们必须牢记在页面加载时可能没有$search_result

<?php
$search_result = NULL;

if(isset($_POST['submit']))
{
    $valueToSearch = $_POST['search'];
    $query = "SELECT * FROM `login` WHERE CONCAT(`id`, `username`, `password`) LIKE '%".$valueToSearch."%'";
    $search_result = filterTable($query);
}

function filterTable($query)
{
    $connect= mysqli_connect("localhost","root","","cable");
    $filter_Result = mysqli_query($connect, $query);
    return $filter_Result;
}

?>
<form action="test.php" method="POST"> 
<div class="container">
    <div class="row">
        <br><br><div class="search">
<input type="text" name="search" class="form-control input-sm" maxlength="64" placeholder="Search" />
 <button type="submit" name="submit" class="btn btn-primary btn-sm">Search</button>
</div>
    </div>
</div>
</br></br>
</form>

<table>
                <tr>
                    <th>Id<br></th>
                    <th>Username:</th>
                    <th>Password</th>
                   </tr>
                                          <?php if(!empty($search_result)): while($row = mysqli_fetch_array($search_result)):?>

                <tr>
                    <td><?php echo $row['id'];?><br></td>
                    <td><?php echo $row['username'];?></td>
                    <td><?php echo $row['password'];?></td>

                </tr>
                <?php endwhile; endif; ?>
            </table>

过滤数据时遇到错误

1 个答案: