mysql>
mysql>
mysql> CREATE TABLE tsdemo2
-> (
-> t_update TIMESTAMP, # record last-modification time
-> t_create TIMESTAMP, # record creation time
-> val INT
-> );
Query OK, 0 rows affected (0.00 sec)
mysql>
mysql> INSERT INTO tsdemo2 (t_update,t_create,val) VALUES(NULL,NULL,5);
Query OK, 1 row affected (0.00 sec)
mysql> SELECT * FROM tsdemo2;
+---------------------+---------------------+------+
| t_update | t_create | val |
+---------------------+---------------------+------+
| 2011-10-03 13:05:52 | 2011-10-03 13:05:52 | 5 |
+---------------------+---------------------+------+
1 row in set (0.00 sec)
mysql>
mysql> UPDATE tsdemo2 SET val = val + 1;
Query OK, 1 row affected (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> SELECT * FROM tsdemo2;
+---------------------+---------------------+------+
| t_update | t_create | val |
+---------------------+---------------------+------+
| 2011-10-03 13:05:52 | 2011-10-03 13:05:52 | 6 |
+---------------------+---------------------+------+
1 row in set (0.00 sec)
mysql>
mysql> SELECT t_create, t_update,
-> UNIX_TIMESTAMP(t_update) - UNIX_TIMESTAMP(t_create) AS 'seconds',
-> (UNIX_TIMESTAMP(t_update) - UNIX_TIMESTAMP(t_create))/(60 * 60) AS 'hours'
-> FROM tsdemo2;
+---------------------+---------------------+---------+--------+
| t_create | t_update | seconds | hours |
+---------------------+---------------------+---------+--------+
| 2011-10-03 13:05:52 | 2011-10-03 13:05:52 | 0 | 0.0000 |
+---------------------+---------------------+---------+--------+
1 row in set (0.00 sec)
mysql>
mysql> drop table tsdemo2;
Query OK, 0 rows affected (0.00 sec)
mysql>