CREATE TABLE `onlineuyeler` ( 
  `id` int(11) NOT NULL auto_increment, 
  `oturumsuresi` varchar(50) NOT NULL, 
  `tip` text NOT NULL, 
  `uye` text NOT NULL, 
  `ip` text NOT NULL, 
 PRIMARY KEY  (`id`) 
) ENGINE=MyISAM  DEFAULT CHARSET=utf8 AUTO_INCREMENT=46 ; 
 
 
 <? 
require ("bagla.php"); 
require ("tani5.php"); 
 $uye = $_SESSION["user"]; 
 $tip = 1; 
 $ip = $_SERVER["REMOTE_ADDR"]; 
 
if(empty($uye)){ 
 $uye = $ip; 
 $tip = 0; 
} 
 $oturumsuresi = time()+60*1; 
 $uyevarmi = mysql_query("SELECT * FROM onlineuyeler WHERE uye='$uye'"); 
if(mysql_num_rows($uyevarmi)>0){ 
 mysql_query("UPDATE onlineuyeler SET oturumsuresi='$oturumsuresi' where uye='$uye'"); 
}else{ 
 mysql_query("INSERT INTO onlineuyeler  (oturumsuresi,tip,uye,ip) values ('$oturumsuresi','$tip','$uye','$ip')"); 
} 
 $suan = time(); 
 mysql_query("DELETE FROM onlineuyeler WHERE zaman<='$suan'"); 
 $sorgu = mysql_query("SELECT * from onlineuyeler WHERE oturumsuresi > ".time()." ORDER BY id ASC");   
 
While($yaz=mysql_fetch_object($sorgu)){ 
if($tip==0){ 
echo "online kimse yok"; 
} 
else 
{ 
echo $yaz->uye."<br>"; 
 
} 
} 
 ?>
Kaynak : online üye göster de mysql hatasi - Ceviz Forum