Charles,

> TIntegerField.Value must return a Longint.  When it encounters a null it
> returns 0.  So VarIsNull(SourceTableMyInteger.Value) = VarIsNull(0) =
> false.
>
> VarIsNull(SourceTableMyInteger.AsVariant) would possibly do what you
> wanted.

Thanks for the explanation. That makes sense.

Uli

Roy,

> Me neither but I use .IsNull out of habit so I wouldn't encounter that.

Charles explained it well.

> My understanding is that parameters are persistent so you'll need to set each time they change.

Yes, that's what I guessed.

Uli

Uli,

<< Thank you. That works indeed. (Though I don't understand why VarIsNull
doesn't work). >>

Charles is correct - Value always returns an Integer value, regardless of
the NULL state.

<< One more question: if I execute the procedure several times with
different parameters: have I to clear the parameters that I want to pass
as NULL like this: >>

Yes, you need to Clear any parameters that you explicitly want to set to
NULL.

--
Tim Young
Elevate Software
www.elevatesoft.com