Sum of resulting set of rows in SQL - sql

Question

I've got the following query:
SELECT DISTINCT CU.permit_id, CU.month, /*CU.year,*/ M.material_id, M.material_name, /*MC.chemical_id, C.chemical_name,
C.precursor_organic_compound, C.non_precursor_organic_compound,*/
/*MC.chemical_percentage,*/
POC_emissions =
CASE
WHEN (C.precursor_organic_compound = 'true')
THEN (CU.chemical_usage_lbs / CU.material_density) * M.VOC
ELSE 0
END,
NON_POC_emissions =
CASE
WHEN (C.non_precursor_organic_compound = 'true')
THEN CU.chemical_usage_lbs * (MC.chemical_percentage / 100)
ELSE 0
END
FROM material M
LEFT OUTER JOIN material_chemical MC ON MC.material_id = M.material_id
LEFT OUTER JOIN chemical_usage CU ON CU.material_id = MC.material_id
LEFT OUTER JOIN chemical C ON C.chemical_id = MC.chemical_id
WHERE (CU.month >=1 AND CU.month <= 2)
AND CU.year = 2013
AND M.material_id = 52
--AND CU.permit_id = 2118
--GROUP BY CU.permit_id, M.material_id, M.material_name, CU.month, MC.chemical_id, MC.chemical_id, C.chemical_name, C.precursor_organic_compound, C.non_precursor_organic_compound
--ORDER BY C.chemical_name ASC
Which returns:
But what I need is to return one row per month per material adding up the values of POC per month and NON_POC per month.
So, I should end up with something like:
Month material_id material_name POC NON_POC
1 52 Krylon... 0.107581 0.074108687
2 52 Krylon... 0.143437 0.0988125
I tried using SUM but it sums up the same result multiple times:
SELECT /*DISTINCT*/ CU.permit_id, CU.month, /*CU.year,*/ M.material_id, M.material_name, /*MC.chemical_id, C.chemical_name,
C.precursor_organic_compound, C.non_precursor_organic_compound,*/
--MC.chemical_percentage,
POC_emissions = SUM(
CASE
WHEN (C.precursor_organic_compound = 'true')
THEN (CU.chemical_usage_lbs / CU.material_density) * M.VOC
ELSE 0
END),
NON_POC_emissions = SUM(
CASE
WHEN (C.non_precursor_organic_compound = 'true')
THEN CU.chemical_usage_lbs * (MC.chemical_percentage / 100)
ELSE 0
END)
FROM material M
LEFT OUTER JOIN material_chemical MC ON MC.material_id = M.material_id
LEFT OUTER JOIN chemical_usage CU ON CU.material_id = MC.material_id
LEFT OUTER JOIN chemical C ON C.chemical_id = MC.chemical_id
WHERE M.material_id = 52
--AND CU.permit_id = 187
AND (CU.month >=1 AND CU.month <= 2)
AND CU.year = 2013
GROUP BY CU.permit_id, M.material_id, M.material_name, CU.month/*, CU.year, MC.chemical_id, C.chemical_name, C.precursor_organic_compound, C.non_precursor_organic_compound*/
--ORDER BY C.chemical_name ASC

Answer 1

The first query has a DISTINCT clause. What is the output without the DISTINCT clause. I suspect you have more rows than shows in your screenshot.
Regardless, you could try something like this to get the desired result.
select permit_id, month, material_id, material_name,
sum(poc_emissions), sum(non_poc_emissions)
from (
SELECT DISTINCT CU.permit_id, CU.month, M.material_id, M.material_name,
POC_emissions =
CASE
WHEN (C.precursor_organic_compound = 'true')
THEN (CU.chemical_usage_lbs / CU.material_density) * M.VOC
ELSE 0
END,
NON_POC_emissions =
CASE
WHEN (C.non_precursor_organic_compound = 'true')
THEN CU.chemical_usage_lbs * (MC.chemical_percentage / 100)
ELSE 0
END
FROM material M
LEFT OUTER JOIN material_chemical MC ON MC.material_id = M.material_id
LEFT OUTER JOIN chemical_usage CU ON CU.material_id = MC.material_id
LEFT OUTER JOIN chemical C ON C.chemical_id = MC.chemical_id
WHERE (CU.month >=1 AND CU.month <= 2)
AND CU.year = 2013
AND M.material_id = 52
) main
group by permit_id, month, material_id, material_name
Explanation
Since the results you retrieved by doing a DISTINCT was consider source-of-truth, I created an in-memory table by making it a sub-query. However, this subquery must have a name of some kind...whatever name. I gave it a name main. Subqueries look like this:
select ... from (sub-query) <give-it-a-table-name>
Simple Example:
select * from (select userid, username from user) user_temp
Advanced Example:
select * from (select userid, username from user) user_temp
inner join (select userid, sum(debits) as totaldebits from debittable) debit
on debit.userid = user_temp.userid
Notice how user_temp alias for the subquery can be used as if the sub-query was a real table.

Answer 2

Use above query in subquery and group by (month) and select sum(POC_emissions) and sum(NON_POC_emissions )