mysql> SELECT @r := 1;
+---------+
| @r := 1 |
+---------+
| 1 |
+---------+
1 row in set (0.00 sec)

mysql> SELECT MAX(r) FROM (SELECT @r := @r * x AS r FROM t) AS t2;
+--------+
| MAX(r) |
+--------+
| 6 |
+--------+
1 row in set (0.01 sec)

Или без вложената заявка:

mysql> SELECT @r := 1;
mysql> SELECT @r := @r * x AS r FROM t ORDER BY r DESC LIMIT 1;

+------+
| r |
+------+
| 6 |
+------+
1 row in set (0.00 sec)

Съдържаниет е скрито
Влезте за да го видите

Редактирано от salle на 25.02.05 17:29.