[AccessD] OT: The Great Primary Debate

Jim,

Perversely, I would state the situation as the inverse of your
statement, as long as you don't change the autonumber, you can change
any attribute without changing the instance. By using this approach,
you provide a solution to fix mistakes in the attributes that make up
the so-called "natural" keys due to miskeying, incomplete information,
or a change in value.

In fact, if you used "natural" keys as your primary key, in order to
fix such mistakes you would have to allow for the very same thing that
you are claiming prevents autonumbers from being natural keys, 
changing an attribute without changing the instance.

Francis R Harvey III
WB 303, (301)294-3952
harveyf1 at westat.com


> -----Original Message-----
> From: accessd-bounces at databaseadvisors.com 
> [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Jim Dettman
> Sent: Monday, June 14, 2004 8:33 AM
> To: Access Developers discussion and problem solving
> Subject: RE: [AccessD] OT: The Great Primary Debate
> 
> 
> Scott,
> 
<snip>
> 
>   No because the serial number would be associated with the 
> instance, so it
> becomes an attribute even though it was assigned.  An 
> autonumber is not.  I
> can change an autonumber at any time with no affect at all.  
> Looking at any
> given row, if I change the autonumber, nothing happens.  If I 
> changed the
> serial number, I'd no longer be referring to the same instance.  One
> meaningless, the other derived from the attributes of what 
> I'm referring to.
> 
> Jim Dettman
> (315) 699-3443
> jimdettman at earthlink.net
<snip>