MySQL建表设置两个默认CURRENT_TIMESTAMP的技巧
业务场景:
例如用户表,我们需要建一个字段是创建时间, 一个字段是更新时间.
解决办法可以是指定插入时间,也可以使用数据库的默认时间.
在mysql中如果设置两个默认CURRENT_TIMESTAMP,会出现这样的错误.
ERROR 1293 (HY000): Incorrect table definition; there can be only one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause.
错误的建表语句:
CREATE TABLE TBL_FUND_FROZEN_UNFROZEN_RECORD ( ID BIGINT NOT NULL AUTO_INCREMENT, TRADE_FLOW_ID VARCHAR(60) NOT NULL, ACCOUNT_NO VARCHAR(32), INITIATOR VARCHAR(16), CREATE_DATE TIMESTAMP default CURRENT_TIMESTAMP, OPERATE_TYPE VARCHAR(32) NOT NULL, FROZEN_AMOUNT DECIMAL(18,2) DEFAULT 0.0 NOT NULL, UNFROZEN_AMOUNT DECIMAL(18,2) DEFAULT 0.0, CREDENTIAL VARCHAR(40) NOT NULL, MODIFY_DATE TIMESTAMP default CURRENT_TIMESTAMP, UNFROZEN_DATE TIMESTAMP, SERIAL_NUM BIGINT NOT NULL, VERSION BIGINT, DECRIPTION VARCHAR(200), CONSTRAINT P_Key_1 PRIMARY KEY (ID) )ENGINE=InnoDB DEFAULT CHARSET=utf8;
使用函数的方式解决该问题：
通过如下方式指定时间戳类型：
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() );
进行如下测试，验证功能是否生效：
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)
文章出处：
http://blog.163.com/user_zhaopeng/blog/static/166022708201252323942430/