Re: SQL issue with EXISTS not "working"

So, given:

1) COMMON_FILE is empty when you start
2) ITEM values are unique in FILE_A

Then I think all the records in FILE_A should be inserted into
COMMON_FILE. Does this happen?

How are you proving "The exists is not working and as a result the insert
is inserting duplicates"? Are you sure you are doing this correctly?

You can check for duplicate ITEMS simply with something like this:
SELECT ITEM,COUNT(*)
FROM COMMON_FILE
GROUP BY ITEM
HAVING COUNT(*) > 1

Sam

On 10/23/2014 10:56 AM, Darryl Freinkel wrote:

I need some help on this one.

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

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