Re: Separate PK in Jxn Tbl?
Date: Sat, 26 Jan 2008 13:05:12 -0400
David Cressey wrote:
> <CDMAPoster_at_fortunejames.com> wrote in message
> On Jan 25, 9:12 am, Jamie Collins <jamiecoll..._at_xsmail.com> wrote:
> What part of simpler don't you understand :-). Only one expression in
> the ON is simpler. Needing less indexes is simpler. Not having to
> look for your multi-key fields is easier, although your point that
> Relationships can handle that is valid. If the AutoNumber key has a
> one-to-one relationship with the multi-key fields then it's fine to
> use it. There's no down side that I can see. I also like to rely on
> coding to detect inconsistent data rather than on error trapping, so I
> have to check the multi-key values anyway before adding a new record.
> I think that your idea about enforcing constraints at both the table
> level and in code is an excellent idea. The OP wanted to know what
> people did and why. I still don't see any reason put forward for me
> to change to a multi-field key. Are totals queries easier when multi-
> field keys are used? BTW, "reduced the amount of denormalization"
> works just as well. Real databases experience denormalizing
> (end quote)
> Simplicity is in the eye of the beholder.
I tend to disagree. I suspect one can quantify simplicity and complexity.
> I think it's simpler to rely on constraints enforced by the DBMS to prevent
> duplicate entries
> than it is to write code to accomplish the same thing.
Using the dbms uses fewer tools, fewer concepts, fewer computational models, fewer structures, fewer machines. I suggest the observed simplicity is more than a matter of perspective or opinion.
[further demonstrations of simplicity snipped] Received on Sat Jan 26 2008 - 18:05:12 CET