Re: Time functions

On Tue, 2002-12-10 at 00:00, Ron St.Pierre wrote:
> Hi, I've got another question about time - timestamps. I need to
> summarize the amount of time a user has used the system for from a table
> listing the userID, startTimestamp, endTimestamp.
>  id    userID     startTimestamp          endTimestamp
> 1     2119     5/10/00 7:32:33 PM     5/10/00 7:33:59 PM
> 2     2119     5/10/00 7:36:30 PM     5/10/00 7:39:27 PM
> 3     2119     5/10/00 7:40:01 PM     5/10/00 9:40:05 PM
> 4     2120     5/10/00 8:11:12 PM     5/10/00 8:11:21 PM
> 5     2121     5/10/00 8:12:26 PM     5/10/00 8:12:46 PM
>
> I don't want to use the interval functions as I don't want the results
> summarized by total months, weeks, days, years, hours, minutes,
> seconds...., I just want the total hours eg 47.98 HOURS
> I couldn't find any suitable way of doing it in the manual or in
> techdocs(.postgresq.org).
>
> Anyone have any suggestions?

Calculate the number of seconds, convert to hours and present with
desired precision:

junk=# SELECT *, TO_CHAR((EXTRACT('epoch' FROM endts) - EXTRACT('epoch'
FROM startts))::NUMERIC/3600, '9999.999') AS hours FROM myt;
 id | userid |       startts       |        endts        |   hours
----+--------+---------------------+---------------------+-----------
  1 |   2119 | 2000-10-05 19:32:33 | 2000-10-05 19:33:59 |      .024
  2 |   2119 | 2000-10-05 19:36:30 | 2000-10-05 19:39:27 |      .049
  3 |   2119 | 2000-10-05 19:40:01 | 2000-10-05 21:40:05 |     2.001
  4 |   2120 | 2000-10-05 20:11:12 | 2000-10-05 20:11:21 |      .003
  5 |   2121 | 2000-10-05 20:12:26 | 2000-10-05 20:12:46 |      .006
(5 rows)



--
Oliver Elphick <olly@lfix.co.uk>
LFIX Limited