RE: SQL issue with EXISTS not "working"

I am merging 5 company records into 1 file and need to drop any duplicates.> This is the statement:
INSERT INTO COMMON_FILE
(SELECT * FROM FILE_A A1
WHERE NOT EXISTS (SELECT 1 FROM COMMON_FILE A2 WHERE A1.ITEM = A2.ITEM))

Problem:
The exists is not working and as a result the insert is inserting
duplicates.

What alternative ways are there to achieve this merge or what mistake am I
not seeing?

I have 5 similar SQL statements to run.

TIA

--
Darryl Freinkel

How about this?


Insert Into COMMON_FILESelectITEM, DESC, etc /* All fields need to be listed here */From(SelectA.*,Row_Number() Over(Partition By ITEM Order By ITEM) As ITEM_RANKFrom(Select*FromFILE_AUnionSelect*FromFILE_BUnionSelect*FromFILE_CUnionSelect*FromFILE_DUnionSelect*FromFILE_E) As A) As BWhereITEM_RANK = 1


Jim