Re: interval question

On 3/6/01, 12:59:40 AM, Fernando "P." Schapachnik
<fernando(at)schapachnik(dot)com(dot)ar> wrote regarding [GENERAL] interval question:

> Hello:
> Maybe somebody on the list can give me a hand with this. I
> have:
> id serial,
> start time,
> duration time

Surely "duration" should be of type interval.
Also - are you sure "start" should be time and not timestamp - depends if
you don't care about dates.

> (That is, ids have an start time and a duration).

> I want to know which ids are current, ie, which satisfy
> start<=now<=start+duration.

SELECT id FROM foo WHERE start<=now() AND now<=(start + duration);

> The problem is that start+duration is an interval, and I
> can't find the way to cast now to interval or interval to time or
> tinterval in order to make the comparison.

The cast should happen automatically. If not, you can do things like:

select now() + '10:00'::interval;
select '2001-03-13'::timestamp;

to convert into interval or a timestamp.