MySQL Query with Multiple Dates - mysql

Question

I'm trying to pull some activity reports for an application based on date ranges (number of "Stars" for each post)
It has a post table that includes and account id, and an "affiliate" table that ties that id to an account.
I know that I can do:
SELECT
posts.affid,
affiliates.name
sum(posts.stars) AS SEPT_2012
from posts
JOIN affiliates on posts.affid = affiliates.id
WHERE posts.timestamp BETWEEN '2012-09-01' AND '2012-10-01'
group by affid
That will pull a result that has the affiliate ID, Name and total "stars" from September. A single month
However, I'd like to do a pull that goes back and gets numbers for August, July, June and May that would display in a single query result (so the result would include affid, name, SEPT_2012, AUG_2012, JUL_2012...etc). Essentially, doing subqueries for those other date ranges, I assume.
Any suggestions?
Thanks for your help!

Answer 1

You probably want to GROUP BY EXTRACT(YEAR_MONTH FROM timestamp) (in addition to whatever else you want to do). Of course it will not get you the SEPT_2012, AUG_2012, etc. columns, but the data will be there.

Answer 2

While you won't be able to dynamically create the columns, you can "fake" them and use a UNION for each date range. Inside each UNION, you select 0 for the other date columns and the SUM() for the correct column.
Something similar to this should work:
SELECT
posts.affid,
affiliates.name,
sum(posts.stars) AS SEPT_2012,
0 AS AUG_2012,
0 AS JUL_2012
from
posts
JOIN affiliates on posts.affid = affiliates.id
WHERE
posts.timestamp BETWEEN '2012-09-01' AND '2012-10-01'
group by affid
UNION (
SELECT
posts.affid,
affiliates.name
0 AS SEPT_2012,
sum(posts.stars) AS AUG_2012,
0 AS JUL_2012
from
posts
JOIN affiliates on posts.affid = affiliates.id
WHERE
posts.timestamp BETWEEN '2012-08-01' AND '2012-09-01'
group by affid
)
UNION (
SELECT
posts.affid,
affiliates.name
0 AS SEPT_2012,
0 AS AUG_2012,
sum(posts.stars) AS JUL_2012
from
posts
JOIN affiliates on posts.affid = affiliates.id
WHERE
posts.timestamp BETWEEN '2012-07-01' AND '2012-08-01'
group by affid
)
UPDATE (to combine all results for each affid on a single row)
Per a comment, you would like to combine the results for each posts.affid on a single row with all of the data in each column. You can achieve this by putting an outer-query around the full query above and then using GROUP BY affid again. With this, you should have a single row for each affid and all of the columns as requested. I've updated the above query to select 0 for each empty column instead of null for "nicer" output too:
SELECT affid, name, SEPT_2012, AUG_2012, JUL_2012 FROM (
... full query above ...
) AS q
GROUP BY affid
UPDATE
To get the sum of all "stars" from all subqueries, the outer select statement works with:
SELECT affid, name, sum(SEPT_2012), sum(AUG_2012), sum(JUL_2012) FROM (
... full query above ...
) AS q
GROUP BY affid