RE: problem with duplicate records

On Wed, 2008-11-19 at 08:36 -0500, Alan Shore wrote:

Not too sure if the problem is that 2 different records have
1. the same Ref#,
or
2. the same time
or
3 .the same Ref#/time

Be that as it may
Why don't you create logicals and have them as keyed unique on whichever of
the above scenarios you do NOT want duplicates of

Of course the applicable programs will need to be changed to monitor for an
attempt to write a duplicate key

I have had to do this when, for reasons which have faded into the mists
of time, no better method for generating sequential numbers was allowed.
The code is ugly in that it has a loop where I would not expect one, but
the code is less fearsome than I would have expected.

Cheers,
Terry.

Alan Shore
Programmer/Analyst, Distribution
E:AShore@xxxxxxxxxxx
P:(631) 200-5019
C:(631) 880-8640
"If you're going through Hell, keep going" - Winston Churchill


rpg400-l-bounces@xxxxxxxxxxxx wrote on 11/19/2008 06:17:15 AM:

Sorry, the contents of my file are misleading. The time isn't part
of the reference number.

ArchiveFile
Product Client Ref Time
Product1 Client1 RefNo1 10:41:57
Product2 Client2 RefNo1 10:41:57


Summing up, 2 jobs writing to the same file. One job is quicker than
the other. The first job calculates the data to write, tests to see
it doesn't already exist and writes the data. In RPG, how should we
prevent another job from doing the same and writing the same data
before the first one?


-----Message d'origine-----
De : rpg400-l-bounces@xxxxxxxxxxxx [mailto:rpg400-l-
bounces@xxxxxxxxxxxx] De la part de David FOXWELL
Envoyé : mercredi 19 novembre 2008 09:33
À : RPG programming on the AS400 / iSeries
Objet : problem with duplicate records

Hi,

Two users have managed to create the same archive reference number
while creating two different clients.

Like this :

ArchiveFile
Product1 Client1 RefNo1 10:41:57(time)
Product2 Client2 RefNo1 10:41:57

The program would crash if the problem occurred with the same
product. As it is 2 users in different services created the records
at the same time.

The user enters the client details and hits the enter key.
The program writes the client to the client file then calls an
external procedure to find an unused archive number then write this
number to the archive file.

The client files look like this
Product1_clients
Client1 created at 10:41:53

Product2_clients
Client2 created at 10:41:56

I'm assuming that the creation of client1 took so long that the
creation of client2 caught up. The same time in the ArchiveFile is
just a hazard.

I can think of ways to fix it, but I'd rather ask what are we doing

wrong?

Thanks.
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