[rules-dev] need advice re null handling

[Michael Neale]

yeah there is some logic to that. Certainly easier to implement ;)

I guess thinking of business rules - nulls are evil things. Even in a
database, they are evil. Many an important report is incorrect cause it is
built on a database that allows null values, and people don't understand the
ramifications of the SQL statements used.

Nulls in your fact model: just say no !

of course... back in the real world...

Some other thoughts:

Foo(bar < 3) makes no sense if bar is null, so it should be false always in
my opinion.

However, Foo(bar != 3) is not so clear for null behaviour.

On 3/15/07, Steven Williams <stevearoonie at gmail.com> wrote:
>
> I agree with SQL. If you also want to catch null you could do
>
> Foo(field > 3 | == null)
>
> cheers
> Steve
>
> On 3/15/07, Michael Neale < michael.neale at gmail.com> wrote:
>
> > http://jira.jboss.com/jira/browse/JBRULES-627
> >
> > OK, this much is clear:
> >
> > Foo(field == null) can be true if field is null.
> >
> > but, what about Foo(field > 3), and field is null? should that be false?
> > what about Foo(field != 3) - should that be true?
> >
> > in SQL, null will always result in a false condition, unless you
> > explicitly use null.
> >
> > Thoughts?
> >
> > Michael.
> >
> > _______________________________________________
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> >
>
>
> --
> Steven Williams
>
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