Re: composite foreign key one field constant?

"Brian E Dick" <bdick_at_cox.net> writes:

> BTW, I have worked with this implementation before and in the long run it's
> a real bastard. Looks like you are trying to avoid multiple code tables by
> merging them into one and adding a type column. Don't do it. Use multiple
> tables. Otherwise, this "simplification" will cost you tons of complicated
> and buggy SQL down the road.
>

Oh how I wish this point could become more widespread.

Out of all the db applications I have worked on over the years, this would be one of the most common design flaws I have come across. I find it difficult to understand why so many designs incorporate the single code table with a type field approach when all the theory indicates it is a bad idea (tm) and anyone who has had to work with such a system knows it leads to additional complications, maintenance problems and a common source of errors.

Tim Received on Wed Nov 20 2002 - 16:00:20 CST