How to correct error when aggregating from subquery - sql

Question

I have a query that looks like this:
SELECT store_id,
(CASE WHEN txns_A>0 AND txns_B=0 THEN 'A Only' WHEN txns_A=0 AND txns_B>0 THEN 'B Only' END) A_B_indicator,
sum(1) cnt_customers,
sum(spend_A+spend_B)/sum(txns_A+txns_B) avg_receipt
FROM(
SELECT store_id, cust_id
SUM(CASE WHEN A_B_indicator='A' THEN spend else 0 end) spend_A,
SUM(CASE WHEN A_B_indicator='B' THEN spend else 0 end) spend_B,
SUM(CASE WHEN A_B_indicator='A' THEN spend else 0 end) txns_A,
SUM(CASE WHEN A_B_indicator='B' THEN spend else 0 end) txns_B
FROM table1
GROUP BY store_id, cust_id
) table2;
However, this generates an error because store_id is not in a GROUP BY clause. When I rewrite the query to include a GROUP BY store_id clause, it complains that the aggregate columns are not in the Group By. However, if I add them by rewriting the Group By to be Group BY 1,2,3,4, this also generates an error (Not yet supported place for UDAF Sum).
How can I rewrite this query to be error-free?

Answer 1

You can write this as:
SELECT store_id,
(CASE WHEN SUM(txns_A) > 0 AND SUM(txns_B) = 0 THEN 'A Only'
WHEN SUM(txns_A) = 0 AND SUM(txns_B) > 0 THEN 'B Only'
END) as A_B_indicator,
COUNT(*) as cnt_customers,
SUM(spend_A+spend_B)/sum(txns_A+txns_B) as avg_receipt
FROM (SELECT store_id, cust_id
SUM(CASE WHEN A_B_indicator='A' THEN spend else 0 end) as spend_A,
SUM(CASE WHEN A_B_indicator='B' THEN spend else 0 end) as spend_B,
SUM(CASE WHEN A_B_indicator='A' THEN spend else 0 end) as txns_A,
SUM(CASE WHEN A_B_indicator='B' THEN spend else 0 end) as txns_B
FROM table1
GROUP BY store_id, cust_id
) table2
GROUP BY store_id;