DB2：通过在Select子句中干扰子查询来分组

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