> From: Helen Borrie
> Have you tried using UDFs? The FBUDF.dll library provides the equivalent
> of Oracle's NVL, which is a CASE construct exactly for returning a value
> when SQL encounters null. These are Firebird UDFs but they should work
> with InterBase 6.

....

> sNVL(Person.Postal1, Person.Postal2) as Postal

....

> Use iNVL if Postal1 and Postal2 are integers or exact numerics.

I wonder, is anybody successfully using these UDFs ? Without problems ?
Recently I played with passing parameters to UDF by descriptors,
and it seems buggy to me. (and I remember other people on this list had problems too).
(I will send more info/examples when I have more time.)

Ivan
http://www.volny.cz/iprenosil/interbase