Selecting a second column with a SUM(SUM(value)) function - sql

Question

I am working on a simple query trying to display the total of the totals for 12 periods. I am using a SUM(SUM(value)) function to retrieve the data that I want, however, I am having a hard time displaying a second column in my result.
SELECT CENTRE, SUM(SUM(AMOUNT)) "TOTAL PAY" FROM AB
WHERE ACCOUNT LIKE 'N%' AND CENTRE = '2001' AND YEAR > 2015 GROUP BY AMOUNT, CENTRE;
The error that I am getting has to do with the grouping of the sentence.
Can you please tell me what I have done wrong. I have solved the problem with a sub-query, but I need to fix this query as well because it is used in a more advanced one as a sub-query.

Answer 1

Your questions is too vague to know for sure what you want. For example, what do you mean by "totals for 12 periods"? Is it that for YEAR > 2015 you have 12 rows? Are you always having CENTRE = in your WHERE clause? If so, this might be what you want:
SELECT
MAX(centre) "CENTRE",
SUM(amount) "TOTAL PAY"
FROM
ab
WHERE
account LIKE 'N%'
AND
centre = '2001'
AND
year > 2015;
Or in case CENTRE = 'smth' might not be in your WHERE clause an you need total values for each CENTRE:
SELECT
centre "CENTRE",
SUM(amount) "TOTAL PAY"
FROM
ab
WHERE
account LIKE 'N%'
/* AND
centre = '2001'*/
AND
year > 2015
GROUP BY
centre;
Or in case for every (or one) CENTRE row you need to have total value of all centres:
SELECT
"CENTRE",
total "TOTAL PAY"
FROM
(
SELECT
centre,
ROW_NUMBER() OVER(PARTITION BY
centre
ORDER BY
0
) rn,
SUM(
amount
) OVER(PARTITION BY
0
) total
FROM
ab
WHERE
account LIKE 'N%'
AND
year > 2015
)
WHERE
rn = 1;