From: Andreas Joseph Krogh <andreak@officenet.no>
Organization: OfficeNet AS
To: pgsql-sql@postgresql.org
Subject: Re: Format intervall as hours/minutes etc
Date: Sun, 16 Sep 2007 21:32:47 +0200
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On Sunday 16 September 2007 17:41:56 Tom Lane wrote:
> Andreas Joseph Krogh <andreak@officenet.no> writes:
> > On Sunday 16 September 2007 13:14:27 Andreas Kretschmer wrote:
> >> You can use extract(epoch, from ...) like this:
> >>
> >> test=3D*# select extract(epoch from '2007-09-22 17:00'::timestamp) -
> >> extract (epoch from '2000-02-20 18:00'::timestamp); ?column?
> >> -----------
> >> 239407200
> >> (1 row)
> >>
> >> Now you can calculate the hours and so on.
> >
> > Yes, this works fine for dates >=3D 1970, but I'm looking for a more
> > general
>
> There's no particular restriction to dates after 1970 there.
>
> > solution which takes an arbitrary interval as input.
>
> Well, you could subtract the two timestamps and then "extract(epoch ...)"
> the resulting interval, but I think you'll get the very same answer.
>
> [ pokes at it ... ]  Hm, we seem to have an overflow problem in the
> interval-to-epoch code for intervals exceeding 60-some years:
>
> regression=3D# select extract(epoch from '2007-09-22 17:00'::timestamp -
> '1940-02-20 18:00'::timestamp); date_part
> ------------
>  2132866800
> (1 row)
>
> regression=3D# select extract(epoch from '2007-09-22 17:00'::timestamp -
> '1930-02-20 18:00'::timestamp); date_part
> -------------
>  -1846567696
> (1 row)
>
> Looks pretty trivial to fix ...

Ok.

=2D-=20
Andreas Joseph Krogh <andreak@officenet.no>
Senior Software Developer / Manager
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