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mysql> create table testdate(
         -> id int not null auto_increment primary key,
         -> time date);
Query OK, 0 rows affected (0.30 sec)
mysql> insert into testdate(time) values('2010-4-23');
Query OK, 1 row affected (0.06 sec)
mysql> select * from testdate;
+----+------------+
| id | time            |
+----+------------+
| 1       | 2010-4-23|
+----+------------+
1 row in set (0.00 sec)
mysql> alter table testdate add column current time;
Query OK, 1 row affected (0.25 sec)
Records: 1      Duplicates: 0      Warnings: 0
mysql> update testdate set current='21:18:00' where id=1;
Query OK, 1 row affected (0.06 sec)
Rows matched: 1      Changed: 1      Warnings: 0
mysql> select * from testdate;
+----+------------+----------+
| id | time           | current      |
+----+------------+----------+
| 1      | 2010-4-23 | 21:18:00 |
+----+------------+----------+
1 row in set (0.00 sec)
mysql> alter table testdate add column combine timestamp;
Query OK, 1 row affected (0.14 sec)
Records: 1     Duplicates: 0     Warnings: 0
mysql> update testdate set combine='20050504212000' where id=1;
Query OK, 0 rows affected (0.00 sec)
Rows matched: 1     Changed: 0     Warnings: 0
mysql> select * from testdate;
+----+------------+----------+---------------------+
| id | time          | current     | combine                |
+----+-------


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