Re: comparing nulls

Galen Boyer <galenboyer_at_yahoo.com> wrote in message news:uhf9dzhg9.fsf_at_yahoo.com...

> TRY:
> select count(*) from t1,t1
> where
> (t1.a1 = t2.a2 or t1.a1 is null or t2.a2 is null)
> and (t1.b1 = t2.b2 or t1.b1 is null or t2.b2 is null)
> and ...

,----

| Yong,
| You probably meant:
|  (t1.a1 = t2.a2 or t1.a1 is null AND t2.a2 is null)
|  and (t1.b1 = t2.b2 or t1.b1 is null AND t2.b2 is null)

Well, I didn't go testing the solution, but I was actually trying to allow for the fact that only one of t1.a1 of t2.a2 might be NULL.

-- 
Galen Boyer
Database Architect
Primix Solutions, www.primix.com