Re: how to construct sql

Hi,
Have you already tried this out?

select MAX(page_count_count) - MIN(page_count_count)
from page_count
group by page_count_pdate.

Best,
Oliveiros

----- Original Message -----
From: "Wes James" <comptekki(at)gmail(dot)com>
To: <pgsql-sql(at)postgresql(dot)org>
Sent: Wednesday, June 02, 2010 5:48 PM
Subject: [SQL] how to construct sql

>I am grabbing a printer total and putting it in a table. The
> page_count is continuously increasing:
>
> page_count_count page_count_pdate
> 10 2010-05-10
> 20 2010-05-10
> 40 2010-05-11
> 60 2010-05-11
> 80 2010-05-11
> 100 2010-05-12
> 120 2010-05-12
> .....
>
> and so on.
>
> I can do:
>
> select sum(page_count_count) from page_count group by page_count_pdate.
>
> and get a total for a day. But this is not the total I want. I want
> the total page count for the day. This would mean getting the first
> page count of the day and then subtracting that from last page_count
> for the day. For 2010-05-11 above it would be
>
> 80 - 40 = 40 total for the day. Is there a way to do this with sql?
>
> thx,
>
> -wes
>
> --
> Sent via pgsql-sql mailing list (pgsql-sql(at)postgresql(dot)org)
> To make changes to your subscription:
> http://www.postgresql.org/mailpref/pgsql-sql