there can be only one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause

建表语句:

create table test_table(   id integer not null auto_increment primary key,   stamp_created timestamp default '0000-00-00 00:00:00',   stamp_updated timestamp default now() on update now() );

测试:

 mysql> insert into test_table(stamp_created, stamp_updated) values(null, null); 
Query OK, 1 row affected (0.06 sec)

mysql> select * from t5; 
+----+---------------------+---------------------+ 
| id | stamp_created       | stamp_updated       |
+----+---------------------+---------------------+
|  2 | 2009-04-30 09:44:35 | 2009-04-30 09:44:35 |
+----+---------------------+---------------------+
2 rows in set (0.00 sec)  

mysql> update test_table set id = 3 where id = 2; 
Query OK, 1 row affected (0.05 sec) Rows matched: 1  Changed: 1  Warnings: 0

mysql> select * from test_table;
+----+---------------------+---------------------+
| id | stamp_created       | stamp_updated       | 
+----+---------------------+---------------------+ 
|  3 | 2009-04-30 09:44:35 | 2009-04-30 09:46:59 | 
+----+---------------------+---------------------+ 
2 rows in set (0.00 sec)

参考这里:

http://*.com/questions/267658/having-both-a-created-and-last-updated-timestamp-columns-in-mysql-4-0