Re: SQL issue with EXISTS not "working"

Yes, this would be true if he uses each statement to add to the common file - so yeah, has to watch out, I guess

I was reading it that the common_file was a new thing - empty - in this case, the UNION is fine, as there is nothing to check against.

Of course, there could be a UNION of the new stuff with the old - into a work file, then CPYF into the production one - something like that.

I do suspect that the test against duplicates is not broad enough - this usually requires testing against the entire record - all fields.

Guess we need to hear from Darryl what he is doing, whether adding to existing or building something brand new.

Cheers
Vern

On 10/23/2014 11:54 AM, John R. Smith, Jr. wrote:

I'm reading his SQL to be that he wants to insert into COMMON_FILE records
that are not already in COMMON_FILE which this UNION does not handle. If he
has a matching record in COMMON_FILE and FILEA, he will get a duplicate
because you are not excluding what is already there.

-----Original Message-----
From: MIDRANGE-L [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of
Vernon Hamberg
Sent: Thursday, October 23, 2014 12:50 PM
To: Midrange Systems Technical Discussion
Subject: Re: SQL issue with EXISTS not "working"

If he uses UNIONs even the duplicates in each file will be removed.

On 10/23/2014 11:37 AM, John R. Smith, Jr. wrote:

Are the duplicates records that are already in common_file or are you
getting duplicates from FILE_A? If the latter, try select distinct *
from...

-----Original Message-----
From: MIDRANGE-L [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of
Darryl Freinkel
Sent: Thursday, October 23, 2014 11:56 AM
To: midrange-l@xxxxxxxxxxxx
Subject: SQL issue with EXISTS not "working"

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

--
Darryl Freinkel
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