Re: Null in subquery returns no records

I know.

The questions were meant to draw out or at least address the fallacies of her assertion.

Regards,

Dan

"Bob Badour" <bbadour_at_golden.net> wrote in message news:cYadnT4sXfDl-bjdRVn-jg_at_golden.net...
> You will do yourself a favour to ignore Dawn. She is an idiot with an axe
to
> grind who doesn't have a clue about effective data management.
>
> Conflating NULL with the relational model is just one of her atrocious
> idiocies.
>
> "Dan" <guntermannxxx_at_verizon.com> wrote in message
> news:FGbVb.244$4e3.185_at_nwrddc02.gnilink.net...
> > What is the difference between a null, an "unknown value," and a null
set?
>
> Who knows really? NULL and 3-valued logic have so many problems they have
> reams written on them. Even if one considers them useful, and I do not,
the
> inconsistencies in SQL render NULL meaningless.
>
> God only knows what Dawn means when she talks about a null set. She might
> mean an empty set and she might not. My guess is she is so confused in her
> thinking she doesn't really know herself.
>
> The products she recommends are simultaneously complex and feeble.
>
>
> > Is a null set an empty set?
> >
> > If a null set means "a set with an unknown set of values", then what
good
> > does that do us from a logical perspective. Isn't that set as worthless
> as
> > an unknown value?
> >
> > What is returned from a null set if you don't use nulls?
> >
> > How does a null set help keep fidelity to two-value logic?
> >
> > Thanks,
> >
> > Dan
> >
> > "Dawn M. Wolthuis" <dwolt_at_tincat-group.com> wrote in message
> > news:c02sjp$q4n$1_at_news.netins.net...
> > > "Jonathan Leffler" <jleffler_at_earthlink.net> wrote in message
> > > news:z%0Vb.17554$uM2.2847_at_newsread1.news.pas.earthlink.net...
> > > > Mike MacSween wrote:
> > > > > New testing rule for Mike - always test with null values.
> > > >
> > > > Alternative rule - always ensure the database stores no nulls!
> > > >
> > > > Not necessarily easy - but a good discipline.
> > > >
> > > <snip>
> > > And perhaps the best option of all -- use one of the databases that
> > employs
> > > a two-valued logic, with NULLs treated as null sets -- much cleaner
and
> > > clearer. Examples are jBASE from www.jbase.com , Revelation from
> > > www.revelation.com and the U2 databases (UniData and UniVerse) from
> > > www.ibm.com (then do a search). You would not be alone as there are
> over
> > > 100,000 companies that use these products (could be a low estimate).
> > >
> > > I'm sure there are others as well that have avoided many of the SQL
and
> > > RDBMS complications. There is nothing holy nor scientifically more
> > correct
> > > about the RDBMS model than many other possibilities. If you have an
> > > opportunity to free yourself of the notion that an RDBMS is required,
> you
> > > are likely to find a more productive environment elsewhere.
> > >
> > > Just thought I'd toss in my two cents even though most people who
share
> > this
> > > opinion keep it quiet. --dawn
> > >
> > >
> >
> >
>
>
Received on Sat Feb 07 2004 - 23:31:58 CET