Re: So what's null then if it's not nothing?

In article <1133736983.556193.140790_at_z14g2000cwz.googlegroups.com>, boston103_at_hotmail.com says...
>
> Jon Heggland wrote:
> [...]
> > "Whatever" should IMO include the (very fundamental) boolean domain, so
> > NULL in the context of boolean should also mean an unknown/missing
> > value.
>
> Did not notice that at first. Using NULL and Boolean in the same
> sentence is as wrong as one can get. Boolean [algebra/logic/whatever]
> means that one talks abot the 2VL propositional logic, any other
> logical constant simply does not belong there.

What do you call the domain { TRUE, UNKNOWN, FALSE }? And by the way, haven't you argued for ages that names don't matter?

What is the type/domain of the expression following the keyword WHERE in SQL? Why should we be prohibited from storing values of this type/domain in the database?

And if we did have a Boolean { TRUE, FALSE } domain in SQL, shouldn't we be able to assign NULL to an attribute of that type?

-- 
Jon