Help with doing SELECT sub query within the SET of an UPDATE statement

Question

After doing some research, it appears as if it's possible to use a SELECT subquery in the SET of an UPDATE statement.  i did find some examples and here is my code, however when I click the "check" button it's saying the field (my entire select subquery) is unknown and neither in one of the specified tables or defined by a "DATA".  Do I have a syntax issue or is there another reason why it's not taking this as a valid statement?  Thanks for the help!
LOOP AT IT_DATA
UPDATE /BIC/AZDP_O0140
   SET /BIC/ZCOUNTER = (SELECT COUNT( DISTINCT MATERIAL )
                        FROM /BIC/AZDP_O0140
                        WHERE MATERIAL EQ IT_DATA-MATERIAL
                        GROUP BY MATERIAL).
ENDLOOP.

Answer 1

my Update does indeed have a WHERE clause but because of the issue i'm having, all my criteria in my WHERE is black text in the ABAP editor.  The editor doesn't even recognize the keywords "WHERE" or "EQ".  Below is my entire statement which contains all WHERE criteria in both the Update and the Subquery, i've just removed it for testing to help simplify the query and eliminate as many other factors as posisble that may be causing problems:
LOOP AT IT_DATA.
   UPDATE /BIC/AZDP_O0140
   SET /BIC/ZCOUNTER = (SELECT COUNT( DISTINCT MATERIAL ) FROM /BIC/AZDP_O0140
   WHERE WHSE_NUM EQ IT_DATA-WAREHOUSE
    AND  PLANT EQ IT_DATA-PLANT
    AND  /BIC/ZTRAN_NO EQ IT_DATA-TRANS_NUM
    AND  DELIV_NUMB EQ IT_DATA-DELIVERY
    AND  MATERIAL EQ IT_DATA-MATERIAL
    GROUP BY MATERIAL)
   WHERE WHSE_NUM EQ IT_DATA-WAREHOUSE
    AND  PLANT EQ IT_DATA-PLANT
    AND  /BIC/ZTRAN_NO EQ IT_DATA-TRANS_NUM
    AND  DELIV_NUMB EQ IT_DATA-DELIVERY
    AND  MATERIAL EQ IT_DATA-MATERIAL.
ENDLOOP.
i should also mention the sources i found were not within the SAP Library but instead on other third-party ABAP websites.  so because i was having issues i wanted to post here to see if anyone else has come up with a working solution.  but if this cannot be done i can likely come up with a solution for my needs using multiple internal tables, this would just have been much easier since i can get a query like this to do what i want in SQL Server.  Thought i could utilize this in ABAP as well.