RE: the idea of unique primary keys to be a solution thathasoutlived its usefulness?

I have a very simple solution ensuring unique keys in whatever file You
want.

Define a num field (9P 0 or larger) to hold a unique record-id and have a
file to to store the last used number for every file. Write a procudure
to retrieve the next ID for use together with write-operations.

         ThisFileID = getNextId('THISFILE')

By doing so You have unique keys also useable for connecting records
(master - detail) while the other keys, i.e. custno, can be changed
without affecting the connection between records because it is
implemented with a kind of internal key structure.

The only drawback is when You are running some raw lists, i.e. in query,
it is more difficult to understand key-connections since they only consists
of numeric IDs.


Helge Bichel hbi@xxxxxxx <mailto:hbi@xxxxxxx>
  _____


-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx
[mailto:rpg400-l-bounces@xxxxxxxxxxxx]On Behalf Of Booth Martin
Sent: Monday, November 17, 2003 9:03 PM
To: rpg400-l@xxxxxxxxxxxx
Subject: Re: the idea of unique primary keys to be a solution
thathasoutlived its usefulness?


Sure. a master file of customer names and addresses. How many primary
addresses can there be? Perhaps not hundreds, but certainly there can easily
be a dozen. Even defining various kinds of addresses as differing record
types isn't enough of a differentiation. Some solution is needed that does
not rely on uniqueness.

Obviously that raises the question of "Well, then where do we mail the
invoice if there can be more than one invoice address?" Fair question. But
what do you do if there are seasonal addresses for the person? What if they
have a winter address and a summer address? Do you use their season as part
of the key, to create uniqueness?


---------------------------------------------------------
Booth Martin http://www.MartinVT.com
Booth@xxxxxxxxxxxx
---------------------------------------------------------

-------Original Message-------

From: RPG programming on the AS400 / iSeries
Date: 11/17/03 13:46:45
To: RPG programming on the AS400 / iSeries
Subject: Re: the idea of unique primary keys to be a solution that
hasoutlived its usefulness?

I understand what you are saying, but can you give a business example of a
file that expanded like this?

Rob Berendt
--
"They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety."
Benjamin Franklin
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