Обсуждение: Getting interval in seconds?

Hi,

How do I convert an interval to the number of seconds?

e.g. I'd like the following to produce a result in seconds.

select ('now'::timestamp - somedate)::interval from sometable;

Thanks,
Link.

On Sun, 10 Jun 2001, Lincoln Yeoh wrote:

> Hi,
>
> How do I convert an interval to the number of seconds?
>
> e.g. I'd like the following to produce a result in seconds.
>
> select ('now'::timestamp - somedate)::interval from sometable;

select date_part('epoch',('now'::timestamp - somedate)::interval) from
sometable;

-alex

Thanks!

Which is better/faster?

select date_part('epoch',('now'::timestamp - somedate)::interval) from
sometable;

Or

select extract (epoch from interval ('now'::timestamp - somedate)) from
sometable;

Should I be using 'now'::timestamp or some function form of it?

Cheerio,
Link.

At 10:34 PM 10-06-2001 -0400, Alex Pilosov wrote:
>On Sun, 10 Jun 2001, Lincoln Yeoh wrote:
>
>> Hi,
>>
>> How do I convert an interval to the number of seconds?
>>
>> e.g. I'd like the following to produce a result in seconds.
>>
>> select ('now'::timestamp - somedate)::interval from sometable;
>
>select date_part('epoch',('now'::timestamp - somedate)::interval) from
>sometable;
>
>-alex
>
>
>

On Sun, 10 Jun 2001, Lincoln Yeoh wrote:

> Thanks!
>
> Which is better/faster?
>
> select date_part('epoch',('now'::timestamp - somedate)::interval) from
> sometable;
>
> Or
>
> select extract (epoch from interval ('now'::timestamp - somedate)) from
> sometable;
Speedwise, I think its the same. _maybe_ the latter is faster, but I
wouldn't bet on it.

> Should I be using 'now'::timestamp or some function form of it?
No difference whether you use now() or 'now'::timestamp.

-alex