Re: delete cascade

Bob Badour wrote:
...
> Paul, I believe you are confusing two things. Whether the delete
> cascades has no bearing on the logic for expressing the condition. The
> <AND> and <OR> expression a la TTM would be the same in either case.
> ...

That is still eluding me. I have marked this thread as "work to do". Perhaps after some time, I'll see the light.

> The normal effect of a constraint is simply to block any inconsistent
> update. You gave an english phrase suggesting all foreign keys should
> cascade deletes, and I gave a similar english phrase suggesting they
> should not. Both are useful.
>
> One must keep in mind a foreign key declaration is a convenient
> shorthand. The plain foreign key declares a constraint and is all
> "what". The "on delete cascade" feature extends the constraint with a
> triggered procedure, which thus combines some "how" with the "what".
> ...

I can buy that as think it was part of my original point even though I didn't say so.

p Received on Wed Apr 18 2007 - 15:58:56 CEST