CASE expression in SQL Server - sql

Question

I have three tables w some records below. I was expecting to return on two distinct Keys with a 'BERRY' in Group field. However, for example the KEYs = 179526189 shows BERRY and COCA instead of just BERRY.
Table A
AGE AGE_IND KEYS
34 (null) 179526189
6 N 179526390
Table B
ID STATUS FK_KEY
16478 (null) 179526189
16478 (null) 179526390
16479 (null) 179526189
16479 (null) 179526390
Table C
FK_ID PRO_CODE DEL_DT
16478 Drug 6/10/2014 12:00:00 AM
16479 Drug (null)
SELECT KEYS,
CASE WHEN (AGE < 18 AND AGE_IND = 'Y') AND (B.STATUS != 'S' or B.STATUS is null) THEN 'APPLE'
WHEN C.PRO_CODE = 'Drug' THEN 'BERRY'
WHEN AGE >= 18 THEN 'COCA'
ELSE 'APPLE' END as Groups,
COUNT(DISTINCT KEYS) AS CT
FROM #tableA A
LEFT OUTER JOIN #tableB B
ON (A.KEYS = B.FK_KEY AND (B.STATUS <>'S' or B.STATUS IS NULL))
LEFT OUTER JOIN #tableC C
ON (B.ID = C.FK_ID AND C.DEL_DT IS NULL)
GROUP BY KEYS,
CASE WHEN (AGE < 18 AND AGE_IND = 'Y') AND (B.STATUS != 'S' or B.STATUS is null) THEN 'APPLE'
WHEN C.PRO_CODE = 'Drug' THEN 'BERRY'
WHEN AGE >= 18 THEN 'COCA'
ELSE 'APPLE' END
running the above query, yields
KEYS Groups CT
179526189 BERRY 1
179526189 COCA 1
179526390 APPLE 1
179526390 BERRY 1
Would you please tell me what is wrong with my CASE expression? so that my expected result yields:
KEYS Groups CT
179526189 BERRY 1
179526390 BERRY 1

Answer 1

You are grouping by GROUPS so you get each one. Choose one! It is not clear how you are choosing 'BERRY', but if you want one row per KEYS, then the idea is to only include that in the GROUP BY:
SELECT KEYS,
MAX(CASE WHEN (AGE < 18 AND AGE_IND = 'Y') AND (B.STATUS != 'S' or B.STATUS is null) THEN 'APPLE'
WHEN C.PRO_CODE = 'FMU' THEN 'BERRY'
WHEN AGE >= 18 THEN 'COCA'
ELSE 'APPLE'
END) as Groups,
COUNT(DISTINCT KEYS) AS CT
FROM #tableA A LEFT OUTER JOIN
#tableB B
ON A.KEYS = B.FK_KEY AND (B.STATUS <>'S' or B.STATUS IS NULL) LEFT OUTER JOIN
#tableC C
ON B.ID = C.FK_ID AND C.DEL_DT IS NULL
GROUP BY KEYS;