Hello,
I have a table containing integer counters associated with particular
datetime like this:
CREATE TABLE `counters` (
...
`when` datetime NOT NULL default '0000-00-00 00:00:00',
`counter` smallint(5) unsigned NOT NULL default '0',
...
);
For some purposes I need to initialize frequently the table for time
sequences with constant time step e.g. since 2003-11-06 8:00 to
2003-11-06 12:00 with time step 15 minutes. It means I need to do
following INSERT commands:
INSERT INTO couters (..., '2003-11-06 8:00', 0, ...);
INSERT INTO couters (..., '2003-11-06 8:15', 0, ...);
INSERT INTO couters (..., '2003-11-06 8:30', 0, ...);
....
INSERT INTO couters (..., '2003-11-06 12:00', 0, ...);
Of course my C code is able to generate such command strings in one
simple loop and send them to the MySQL server. But the code should be
as fast as possible and I prefer to do this task by one INSERT-SELECT
command like this:
INSERT INTO counters SELECT ...
Unfortunately I do not have any idea how to build such SELECT command
that will generate the datetime sequence for me. Does anybody know how
to do it? I would appreciate any hints very much.
Thanks, Petr