Php表值未显示

我是PHP新手，现在我有一个问题，为什么我的表值“课程名称、课程ID、学时、课程号、课程部分和容量””没有显示？ 请帮帮我。我们将不胜感激。这是我的密码

<?php include("include/header.php");?>

<link href="layout/styles/layout.css" rel="stylesheet" type="text/css" media="all">

<?php 

include("include/config.php");

$sql = "SELECT * FROM course_list WHERE c_program IN ('DIP-ALL','DIP-ALL','MPU-DIP')";

$query = mysqli_query($link,$sql) or die(mysqli_error($link));

?>

<table width="70%" cellpadding="5" cellspacing="5">
<tr>
   <td><strong>Course Name</strong></td>
   <td><strong>Course ID</strong></td>
   <td><strong>Credit hours</strong></td>
   <td><strong>Class Number</strong></td>
   <td><strong>Class Section</strong></td>
   <td><strong>Capacity</strong></td>
</tr>

<?php while ($row = mysqli_fetch_array($query)) { ?>
<tr>
   <td><?php echo $row['c_cnm']; ?></td>
   <td><?php echo $row['c_cid']; ?></td>
   <td><?php echo $row['c_chrs']; ?></td>
   <td><?php echo $row['c_cnum']; ?></td>
   <td><?php echo $row['c_csec']; ?></td>
   <td><?php echo $row['c_capacity']; ?></td>
</tr>
<?php } ?>

</table>

<?php include("include/footer.php");?>

当您直接通过MySQL/PHPMyadmin执行时，SQL查询是否返回数据？当您直接通过MySQL/PHPMyadmin执行时，SQL查询是否返回数据？