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Old August 6th, 2007, 06:08 PM posted to microsoft.public.access.tablesdbdesign
BruceM[_2_]
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Default PK - To AutoNumber or Not To AutoNumber - That is the Question

The employee number used in the example is as meaningless as a random or
sequential number (unless the "E" has some special significance). The
example is unclear as to whether the form number is the form identifier
(such as Form 1040) or a sequence number. I will assume the latter. The
author seems to be saying that the only possible natural key comprises the
employee number of the employee making the purchase; the form number, which
is already unique; and the date. Since the form number is already unique,
it is unclear how much more unique the record would be with the addition of
two additional fields to the key. Even if there is an argument in the
article's labored logic that there should be a compound key, it does not
address the question about whether the employee ID should be autonumber or
another format.

"Jamie Collins" wrote in message
ps.com...
On 4 Aug, 00:12, "Jeff Boyce" wrote:
I tend to use Autonumber PKs for most of my tables


See:

Business Rules Require Real-World Identifiers
by Dr. John K. Sharp

http://www.inconcept.com/JCM/May1998/sharp.html

"...Let's analyze a simple example of a petty cash reimbursement to an
employee to see how a meaningless unique key is not sufficient for
business rule enforcement..."

Jamie.

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