Grouping the results of a query with CTEs - sql

Question

I have a CTE based query into which I pass about 2600 4-tuple latitude/longitude values - that have been ID tagged and held in a second table called coordinates. These top left and bottom right latitude / longitude values are passed into the CTE in order to display the amount of requests (hourly) made within those coordinates for given two timestamps).
However, I would like to get the total requests per day within the timestamps given. That is, I want to get the total count of user requests on every specified day. E.g. user opts to see every Wednesday or Wednesday AND Thursday etc. - between 11:55 and 22:04 between dates January 1 and 16, 2012 for every latitude/longitude 4-tuples I pass. The output would basically be like:
coordinates_id | stamp | zcount
1 Jan 4 2012 200 (total requests on Wednesday Jan 4 between 11:55 and 22:04)
1 Jan 11 2012 121 (total requests on Wednesday Jan 11 between 11:55 and 22:04)
2 Jan 4 2012 255 (total requests on Wednesday Jan 4 between 11:55 and 22:04)
2 Jan 11 2012 211 (total requests on Wednesday Jan 11 between 11:55 and 22:04)
.
.
.
How would I do that? My query is as below:
WITH v AS (
SELECT '2012-01-1 11:55:11'::timestamp AS _from -- provide times once
,'2012-01-16 22:02:21'::timestamp AS _to
)
, q AS (
SELECT c.coordinates_id
, date_trunc('hour', t.calltime) AS stamp
, count(*) AS zcount
FROM v
JOIN mytable t ON t.calltime BETWEEN v._from AND v._to
AND (t.calltime::time >= v._from::time AND
t.calltime::time <= v._to::time) AND
(extract(DOW from t.calltime) = 3)
JOIN coordinates c ON (t.lat, t.lon)
BETWEEN (c.bottomrightlat, c.topleftlon)
AND (c.topleftlat, c.bottomrightlon)
GROUP BY c.coordinates_id, date_trunc('hour', t.calltime)
)
, cal AS (
SELECT generate_series('2011-2-2 00:00:00'::timestamp
, '2012-4-1 05:00:00'::timestamp
, '1 hour'::interval) AS stamp
FROM v
)
SELECT q.coordinates_id, cal.stamp, COALESCE (q.zcount, 0) AS zcount
FROM v, cal
LEFT JOIN q USING (stamp)
WHERE (extract(hour from cal.stamp) >= extract(hour from v._from) AND
extract(hour from cal.stamp) <= extract(hour from v._to)) AND
(extract(DOW from cal.stamp) = 3)
AND cal.stamp >= v._from AND cal.stamp <= v._to
GROUP BY q.coordinates_id, cal.stamp, q.zcount
ORDER BY q.coordinates_id ASC, stamp ASC;
And the sample result it yields is like this:
coordinates_id | stamp | zcount
1 2012-01-04 16:00:00 1
1 2012-01-04 19:00:00 1
1 2012-01-11 14:00:00 1
1 2012-01-11 17:00:00 1
1 2012-01-11 19:00:00 1
2 2012-01-04 16:00:00 1
So, as I mentioned above, I would like to see this as
coordinates_id | stamp | zcount
1 2012-01-04 2
1 2012-01-11 3
2 2012-01-04 1

Answer 1

Change your final SELECT to:
SELECT q.coordinates_id, cal.stamp::date, sum(q.zcount) AS zcount
FROM v, cal
LEFT JOIN q USING (stamp)
WHERE extract(hour from cal.stamp) BETWEEN extract(hour from v._from)
AND extract(hour from v._to)
AND extract(DOW from cal.stamp) = 3
AND cal.stamp >= v._from
AND cal.stamp <= v._to
GROUP BY 1,2
ORDER BY 1,2;
The crucial part it to cast cal.stamp to date: cal.stamp::date.
That, and sum(q.zcount).