Re: On view updating
Date: Wed, 29 Sep 2004 15:36:46 -0400
Message-ID: <pvCdnRrp-JR6k8bcRVn-rw_at_comcast.com>
"Tony Douglas" <tonyisyourpal_at_netscape.net> wrote in message news:bcb8c360.0409290832.4af7e3_at_posting.google.com...
> > Now to deal with it if you don't have global NULLs I'm not sure...
> > Maybe you could make it a compulsory part of a type definition to define
> > one value for each type that means "data unknown"?
> >
Nah! Just back off from the kludge of calling a NULL a "special value". Call it what it is: an alternative to a value.
You can call the intersection of a row and a column a "field", as long as
you can keep Joe Celko from having apoplexy.
Then you can say that every field contains either a NULL or a value from
its domain.
Domains (or types, if that's better) don't need NULL included.
>
> I'm never keen on "thou shalt"s like this - there's always someone who
> "shalt not". Maybe you have types that never need to handle "data
> unknown" conditions ?
A NULL is like the curious incident of the dog in the night.
I'm not keen on "thou shalt not refer to Oracle RDBMS, DB2, or SQL Server
as relational"!