>> The adequacy of NULLs has been a hotly debated topic since the beginning, even among the most seasoned veteran SQL Academics and DBAs, including the likes of Chris Date,...

Don't go there!!!!

If you are enforcing business rules outside of the DBMS, then you have poorly designed your database, or don't fully understand what a database is.

Your conceptual model (or business model)...

>> it doesn't always hold true for legacy systems. In the latter, most logical models remain well after the person who made the business rule has moved on or changed priorities. ...

Not quite but nearly... business rules that form your business model, which forms your logical model, are enforced by the DBMS.

Such things as "when someone does this, or tries to do...

Your business model (including business rules) drives your logical model (i.e. the database implementation) and thus the "principles behind that model" should be one and the same.

In your zero-balance example,...

You need PKs and FKs in a proper database design, so why not implement them in the DBMS?  What do you gain that outweighs what you are losing?  The idea is...

(Bump)

Is there anyone else in the UK that is interested in this? Thanks.

>> Please replace it with one of those mind-reading ones as soon as possible. <<

That would be quite amusing actually.  Given that you can "censor" your own thoughts when typing,...

>> When you send out a communication from your company, email, fax, or even phone these days with Caller ID, you are representing that company. And your interactions and dealings...

Now if you want a fast car, look no further than the Bugatti Veyron.

Featured recently on BBC's Top Gear, it is now...

>> The reason i was working on some alternate value is 'NULL' breaks the boolean logic. <<

You're trying to apply a value from 3-valued logic (NULL) to 2-valued logic. ...

OK, I've heard back.

I mentioned the two subjects you'd suggested, Mark, and he said on this:

"Good choice. These are new and revised works with some new positions. This will take...

Thanks for the reply, Mark.  I'd agree on your choice of subjects.  I'm also very interested in his proposals for missing values (and have read his paper "The Final NULL...

>>Midget-naked-mud-wrestling channel<<

That probably exists!

>>I've had BSkyB for 4 years but it has occurred to me that with the exception of 24 virtually everything...