Re: object algebra

"Marshall Spight" <mspight_at_dnai.com> wrote in message news:6X90c.81512$4o.104343_at_attbi_s52...
> "Neo" <neo55592_at_hotmail.com> wrote in message
news:4b45d3ad.0402281221.431f280_at_posting.google.com...
> > > The above isn't a "patch for" nulls. What does "weaker relationship"
mean,
> > > though? I have no idea how to address that one.
> >
> > Given EyeColor = {red, brown, N/A} and the table:
> > Person EyeColor
> > ------ --------
> > John N/A
> > Mary N/A
> >
> > A query to find persons with equal eyeColor returns: John & Mary.
>
> So, for example, if you asked the system to find all the pairs of
> people such that the eye color of all the eyes of the first person
> in the pair is equal to the eye color of all the eyes of the second
> person in the pair, then it darn well better return John and Mary,
> because they fit that description.

Unless the equality operation is written to treat the comparison differently. Received on Sun Feb 29 2004 - 05:27:58 CET