Re: [rules-dev] need advice re null handling
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(a)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(a)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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