新手求帮助！请大神看看到底是啥原因？？Fatal error: Call to a member function fetch() on a non-object in D:\Adobe Dreamw

<ul>
            <?php 
    $rsnews=$conn->query("SELECT*FROM jx_news ORDER BY ntime DESC LIMIT 0,6");
    $rownews=$rsnews->fetch();
   ?>
             <li><a href="#">
     <?php echo $rownews['ntitle']
     ?></a></li>
        
            </ul>