MYSQL自动写入当前时间。

定义t5由一个自增字段，一个默认当前时间戳并update时随动更新字段组成。


mysql> CREATE TABLE t5 (
  id int NOT NULL AUTO_INCREMENT PRIMARY KEY,
  css timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  v int(11) DEFAULT NULL );


Query OK, 0 rows affected (0.13 sec)




mysql> insert into t5(v) values (1);
Query OK, 1 row affected (0.06 sec)


mysql> select * from t5;
+----+---------------------+------+
| id | css                 | v    |
+----+---------------------+------+
|  1 | 2012-09-06 08:04:29 |    1 |
+----+---------------------+------+
1 row in set (0.00 sec)


mysql> update t5 set v=2;
Query OK, 1 row affected (0.03 sec)
Rows matched: 1  Changed: 1  Warnings: 0


mysql> select * from t5;
+----+---------------------+------+
| id | css                 | v    |
+----+---------------------+------+
|  1 | 2012-09-06 08:04:44 |    2 |
+----+---------------------+------+
1 row in set (0.00 sec)








mysql> insert into t6 values();      --这样的情况有意思