Обсуждение: getting extract to always return number of hours

Hi,

I'm trying to get extract() to always return the number of hours between 
two time intervals, ala:

=> create table t1(timestart timestamp, timeend timestamp);
=> insert into t1(timestart, timeend) values ('2010-01-01 00:00:00', 
'2010-01-02 01:00:00');

=> select timeend - timestart from t1;    ?column?
---------------- 1 day 01:00:00
(1 row)

to return 25 hours.

I couldn't see anything in the docs and can't work out a way to do it.

Any suggestions?

Thanks!
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On Tue, Jan 5, 2010 at 6:33 PM, Chris <dmagick@gmail.com> wrote:
> I'm trying to get extract() to always return the number of hours between two
> time intervals, ala:

SELECT extract(epoch from timeend - timestart) / 3600 from t1;

rls

-- 
:wq

Chris wrote:
> Hi,
> 
> I'm trying to get extract() to always return the number of hours between 
> two time intervals, ala:
> 
> => create table t1(timestart timestamp, timeend timestamp);
> => insert into t1(timestart, timeend) values ('2010-01-01 00:00:00', 
> '2010-01-02 01:00:00');
> 
> => select timeend - timestart from t1;
>     ?column?
> ----------------
>  1 day 01:00:00
> (1 row)
> 
> to return 25 hours.

I ended up with

select extract('days' from x) * 24 + extract('hours' from x) from 
(select (timeend - timestart) as x from t1) as y;

mainly because t1 is rather large so I didn't want to run the end - 
start calculation multiple times.

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