我有这个问题
UPDATE trh_adminLoginDate SET superseded = true WHERE EXISTS
(SELECT * FROM trh_adminLoginDate AS a2 WHERE a2.adminId = a.adminId AND a2.loginDate > a.loginDate AND a2.clientPlatform = a.clientPlatform)
表格看起来像这样。
+----------------+--------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+----------------+--------------+------+-----+---------+----------------+
| id | bigint(20) | NO | PRI | NULL | auto_increment |
| dateCreated | datetime | NO | | NULL | |
| version | int(11) | NO | | NULL | |
| dateModified | datetime | NO | | NULL | |
| adminId | bigint(20) | NO | MUL | NULL | |
| clientPlatform | varchar(255) | YES | | NULL | |
| loginDate | datetime | YES | | NULL | |
| superseded | tinyint(1) | NO | | NULL | |
+----------------+--------------+------+-----+---------+----------------+
当我执行此查询时，出现以下错误:
ERROR 1093 (HY000): You can't specify target table 'a' for update in FROM clause
我可以创建临时表并保留子查询的结果，然后执行更新。但我不想这样做。有人可以建议我更好的方法吗？
最佳答案
您正在使用别名“a”，但您从未定义它。
也许这会起作用:
UPDATE trh_adminLoginDate a
JOIN trh_adminLoginDate AS a2
ON a2.adminId = a.adminId
AND a2.loginDate > a.loginDate
AND a2.clientPlatform = a.clientPlatform
SET a.superseded = true
关于mysql - 错误 1093 (HY000) : You can't specify target table 'a' for update in FROM clause，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/13188002/