MYSQL中TIMESTAMP类型可以设定默认值,就像其他类型一样。 1、自动UPDATE 和INSERT 到当前的时间: 表: /*DDL Information For - test.t1*/ ---------------------------------
Table Create Table ------ ------------------------------------------------------------------------------------- t1 CREATE TABLE `t1` ( `p_c` int(11) NOT NULL, `p_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP ) ENGINE=InnoDB DEFAULT CHARSET=gb2312
数据:
1 2007-10-08 11:53:35 2 2007-10-08 11:54:00
insert into t1(p_c) select 3; update t1 set p_c = 2 where p_c = 2;
数据:
1 2007-10-08 11:53:35 2 2007-10-08 12:00:37 3 2007-10-08 12:00:37
2、自动INSERT 到当前时间,不过不自动UPDATE。
表: /*DDL Information For - test.t1*/ ---------------------------------
Table Create Table ------ --------------------------------------------------------- t1 CREATE TABLE `t1` ( `p_c` int(11) NOT NULL, `p_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ) ENGINE=InnoDB DEFAULT CHARSET=gb2312
数据: insert into t1(p_c) select 4; update t1 set p_c = 3 where p_c = 3;
1 2007-10-08 11:53:35 2 2007-10-08 12:00:37 3 2007-10-08 12:00:37 4 2007-10-08 12:05:19
3、一个表中不能有两个字段默认值是当前时间,否则就会出错。不过其他的可以。 表: /*DDL Information For - test.t1*/ ---------------------------------
Table Create Table ------ --------------------------------------------------------------- t1 CREATE TABLE `t1` ( `p_c` int(11) NOT NULL, `p_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP, `p_timew2` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00' ) ENGINE=InnoDB DEFAULT CHARSET=gb2312
数据: 1 2007-10-08 11:53:35 0000-00-00 00:00:00 2 2007-10-08 12:00:37 0000-00-00 00:00:00 3 2007-10-08 12:00:37 0000-00-00 00:00:00 4 2007-10-08 12:05:19 0000-00-00 00:00:00
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