DB2: group by interfering subquery in Select clause - select

Question

I'm stuck with a SQL query. I'm making a subquery in the select clause and db2 prompts a -119 error telling:
"An expression starting with "FACILITY_ID" specified in a SELECT clause, HAVING clause, or ORDER BY clause is not specified in the GROUP BY clause or it is in a SELECT clause, HAVING clause, or ORDER BY clause with a column function and no GROUP BY clause is specified. SQL Code: -119, SQL State: 42803"
I don't know how to include NUMTAGS in the GROUP BY. I tried including the BC.ITEM in the GROUP BY clause with no result. I don't know how exactly to look for this in the web, and the forums I looked at were no useful.
If someone could explain me how to mend this or paste a link where I could look for a solution, I would be grateful.
The SQL query is with DB2 and it's down here:
SELECT SS.NAME, B.DESTINATION_ID, P.DESCRIPTION, B.LAST_READ_DATE, B.LABEL,
(SELECT COUNT(BC.ITEM)
FROM PROJECT_DB.BOX_CONTENT BC
WHERE BC.FACILITY_ID = B.FACILITY_ID
AND BC.BOX_ID = B.BOX_ID
GROUP BY BC.ITEM) AS NUMTAGS,
B.BOX_ID
FROM PROJECT_DB.BOX B
INNER JOIN MAINDB.DESTINATION P ON B.DESTINATION_ID = P.DESTINATION_ID
INNER JOIN MAINDB.WAREHOUSE_DESTINATION_SECTION WH
ON B.DESTINATION_ID = WH.DESTINATION_ID
AND B.WAREHOUSE_ID = WH.WAREHOUSE_ID
INNER JOIN MAINDB.SECTION S ON S.SECTION = WH.SECTION
AND S.SECTION_TYPE = B.SECTION_TYPE
INNER JOIN MAINDB.DESTINATION_SET SS
ON SS.DESTINATION_SET_ID = S.DESTINATION_SET_ID
WHERE B.WAREHOUSE_ID = 100
GROUP BY B.BOX_ID, B.FACILITY_ID, B.DESTINATION_ID, B.LAST_READ_DATE, B.LABEL, P.DESCRIPTION, SS.NAME

Answer 1

You can correct the statement by: v including the columns in the GROUP
BY clause that are in the SELECT clause, or v removing the columns
from the SELECT clause.
From: DB2 documentation.
You need to put ALL selected columns in your GROUP BY...

Answer 2

Since you're using a scalar sub-select, I don't think you need a GROUP BY clause on either of your statements. Try this:
SELECT
SS.NAME,
B.DESTINATION_ID,
P.DESCRIPTION,
B.LAST_READ_DATE,
B.LABEL,
(SELECT COUNT(BC.ITEM)
FROM PROJECT_DB.BOX_CONTENT BC
WHERE BC.FACILITY_ID = B.FACILITY_ID
AND BC.BOX_ID = B.BOX_ID
) AS NUMTAGS,
B.BOX_ID
FROM PROJECT_DB.BOX B
JOIN MAINDB.DESTINATION P
ON B.DESTINATION_ID = P.DESTINATION_ID
JOIN MAINDB.WAREHOUSE_DESTINATION_SECTION WH
ON B.DESTINATION_ID = WH.DESTINATION_ID
AND B.WAREHOUSE_ID = WH.WAREHOUSE_ID
JOIN MAINDB.SECTION S
ON S.SECTION = WH.SECTION
AND S.SECTION_TYPE = B.SECTION_TYPE
JOIN MAINDB.DESTINATION_SET SS
ON SS.DESTINATION_SET_ID = S.DESTINATION_SET_ID
WHERE B.WAREHOUSE_ID = 100

Answer 3

My final working query is this down here. I think I had the wrong tables referenced at the "group by" or something similar:
SELECT SS.NAME, P.DESTINATION_ID, P.DESCRIPTION, B.LAST_READ_DATE, B.LABEL,
(SELECT COUNT(BC.ITEM)
FROM PROJECT_DB.BOX_CONTENT BC
WHERE BC.ID_FACILITY = B.ID_FACILITY
AND BC.ID_BOX = B.ID_BOX
GROUP BY BC.ITEM) AS NUMTAGS,
B.BOX_ID, B.FACILITY_ID
FROM PROJECT_DB.BOX B
INNER JOIN MAINDB.DESTINATION P ON B.DESTINATION_ID = P.DESTINATION_ID
INNER JOIN MAINDB.WAREHOUSE_DESTINATION_SECTION WH
ON WH.WAREHOUSE_ID = B.WAREHOUSE_ID
AND WH.ID_DESTINATION = B.ID_DESTINATION
INNER JOIN MAINDB.SECTION S ON S.SECTION = WH.SECTION
AND S.SECTION_TYPE = B.SECTION_TYPE
INNER JOIN MAINDB.DESTINATION_SET SS ON SS.DESTINATION_SET_ID = S.DESTINATION_SET_ID
WHERE B.WAREHOUSE_ID = 100
GROUP BY B.BOX_ID, B.FACILITY_ID, P.DESTINATION_ID, B.LAST_READ_DATE, B.LABEL, P.DESCRIPTION, SS.NAME
WITH UR