Re: week ending

On 7/5/06, Keith Worthington <KeithW(at)narrowpathinc(dot)com> wrote:
> Hi All,
>
> I just finished writing a query that groups data based on the week number.
>
> SELECT EXTRACT(week FROM col_a) AS week_number,
> sum(col_b) AS col_b_total
> FROM foo
> WHERE foobar
> GROUP BY EXTRACT(week FROM col_a)
> ORDER BY EXTRACT(week FROM col_a);
>
> I would like to generate the starting date or ending date based on this
> number. IOW instead of telling the user "week number" which they won't
> understand I would like to provide either Friday's date for "week
> ending" or Monday's date for "week beginning".
>
> SELECT <something> AS week_ending,
> sum(col_b) AS col_b_total
> FROM foo
> WHERE foobar
> GROUP BY EXTRACT(week FROM col_a)
> ORDER BY EXTRACT(week FROM col_a);
>
> --
>
> Kind Regards,
> Keith

select
max(case when (to_char(col_a,'d') between 2 and 6) then col_a end) as
week_ending,
sum(col_b) as col_b_total from foo
where foobar
group by extract(year from col_a), extract(week from col_a)
order by extract(year from col_a), extract(week from col_a);

Regards,

Rodrigo