subtract minutes from a time value

Question

I have a time field in my database, it has the value 22:05

I want to subtract 5 minutes. When the field is datetime I use sub_date and works fine, but I can't get it with time field, I get a warning I don't know how to deal with;

mysql>  SELECT scheduleFinalTime FROM clientSchedule WHERE clientScheduleID = 3;
+-------------------+
| scheduleFinalTime |
+-------------------+
| 22:05:00          |
+-------------------+
1 row in set (0.00 sec)

mysql> SELECT date_sub(scheduleFinalTime, INTERVAL 5 MINUTE) FROM clientSchedule WHERE clientScheduleID = 3;
+------------------------------------------------+
| date_sub(scheduleFinalTime, INTERVAL 5 MINUTE) |
+------------------------------------------------+
| NULL                                           |
+------------------------------------------------+
1 row in set, 1 warning (0.00 sec)

mysql> show warnings;
+---------+------+------------------------------------------------------------+
| Level   | Code | Message                                                    |
+---------+------+------------------------------------------------------------+
| Warning | 1264 | Out of range value for column 'scheduleFinalTime' at row 1 |
+---------+------+------------------------------------------------------------+
 1 row in set (0.00 sec)

Thank you in advance

Answer 1

Mysql has a SUBTIME() function for this.

SUBTIME(expr1,expr2)

SUBTIME() returns expr1 − expr2 expressed as a value in the same format as expr1. expr1 is a time or datetime expression, and expr2 is a time expression.

mysql> SELECT SUBTIME('2007-12-31 23:59:59.999999','1 1:1:1.000002');
        -> '2007-12-30 22:58:58.999997'
mysql> SELECT SUBTIME('01:00:00.999999', '02:00:00.999998');
        -> '-00:59:59.999999'

Answer 2

For those using mysql 4.x

SEC_TO_TIME(TIME_TO_SEC(t2) - TIME_TO_SEC(t1))