Re: graphing time series data

On Wed, Apr 14, 2010 at 7:54 AM, Louis-David Mitterrand
<vindex+lists-pgsql-sql(at)apartia(dot)org> wrote:

> Now, I'd like to make a graph of average prices per week, per
> id_product. As some prices don't vary much, distribution would not be
> ideal if I simply 'group by extract(week from p.modified)'.

I created a view for a similar problem that I had. Only I was
calculating the counts per day. this query could be crafted to work
for you.

CREATE OR REPLACE VIEW opendiscrepencydailycounts AS
WITH opendays(day) AS (
SELECT gs.day::date AS day
FROM generate_series((( SELECT
min(discrepencylist.discstartdt) AS min
FROM discrepencylist))::timestamp without time
zone, 'now'::text::date::timestamp without time zone, '1
day'::interval) gs(day)
)
SELECT opendays.day, ds.resolvingparty, count(opendays.day) AS
opendiscrepancies
FROM discrepencylist ds, opendays
WHERE opendays.day >= ds.discstartdt AND opendays.day <=
LEAST('now'::text::date, ds.resolutiondate)
GROUP BY opendays.day, ds.resolvingparty
ORDER BY opendays.day, ds.resolvingparty;

--
Regards,
Richard Broersma Jr.

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