mysql> SELECT id,playername,ogame_playerid,COUNT(*) As Amount FROM `players` GROUP BY  playername HAVING COUNT(*) > 1 LIMIT 5;
+-------+------------+----------------+--------+
| id    | playername | ogame_playerid | Amount |
+-------+------------+----------------+--------+
| 13255 |            |         110259 |     12 |
| 14055 | -hg-       |           NULL |      2 |
| 17787 | -Revenge-  |           NULL |      2 |
| 18268 | -Sfiber-   |         128390 |      2 |
| 22466 | 12coliche  |           NULL |      2 |
+-------+------------+----------------+--------+
5 rows in set (0.00 sec)

mysql> SELECT id,playername,ogame_playerid,COUNT(*) As Amount FROM `players` WHERE ogame_playerid > 0 GROUP BY  playername HAVING COUNT(*) > 1 LIMIT 5;
+-------+----------------+----------------+--------+
| id    | playername     | ogame_playerid | Amount |
+-------+----------------+----------------+--------+
| 18268 | -Sfiber-       |         128390 |      2 |
| 18222 | Abraxas        |         111099 |      2 |
| 20067 | Account Libero |         110188 |      2 |
| 18561 | Ace            |         133492 |      2 |
|  2539 | Achille nero   |         106639 |      2 |
+-------+----------------+----------------+--------+
5 rows in set (1.03 sec)

mysql>