<?
function kontrol($link) {
   $sql = mysql_query("SELECT permalink FROM tabloadi WHERE permalink='".$link."'");
   if (mysql_num_rows($sql) == 0)
     return $link;
   else {
     $rand = rand(1, 100);
     $link = $link."-".$rand;
     return kontrol($link);
   }
}

$permalink = 'sef-url'; // örnek permalink
$permalink = kontrol($permalink);
?>