MySQL Timestamp的使用

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