尝试从php中排序表时，我收到MYSQL错误

Question

我正在尝试从PHP中对表进行排序，但我得到一个错误的错误＆＃34;警告：mysqli_fetch_array（）期望参数1为mysqli_result＆＃34;

<?php
  $con = mysqli_connect('localhost'  , 'root' , '' ,'profile'); */ connection */

    $fname= 'fname';
    $age = 'age'; 
    if (isset($_GET['order'])) {
        $order = $_GET['order'];
                }
    else {
        $order = 'fname';
    }
    if (isset($_GET['sort'])) {
        $sort = $_GET['sort'];
    }else{
        $sort = 'ASC' ;
    }               
    $res = "SELECT * FROM profile ORDER BY $order $sort";
    $sql = mysqli_query($con,$res); */connecting with mysql database from $con */
    ?>
    <table>
    <tr>
        <th><a href="?order=fname&&sort=$sort">First Name</a></th>
        <th><a href="?order=age&&sort=$sort">Age</a></th>
    </tr>
    <?php   while($rows=mysqli_fetch_array($sql)) :  ?>
    <tr>    
    <td><?php   echo $rows[$fname];
            ?></td>
    <td><?php   echo $rows[$age];
            ?></td>
    </tr>  <?php endwhile;  ?> </table>