Print Random Record in PHP

<?php      
$sql = "select * from category order by RAND() limit 20";    
$q1 = mysql_query($sql) or die(mysql_error() . $sql);
while($r=mysql_fetch_assoc($q1))   
{
?>
<div class="col-md-3 col-sm-4 col-xs-6">
<div class="category-item">
<a href="search-result.php"><?php echo $r['name']; ?></a>
</div>
</div>
<?php
}
?>