Hi, Martijn!

> > > ABS> If (
> > > ABS> (Old.Quantity <> New.Quantity) or
> > > ABS> ((Old.Quantity is null) and (New.Quantity is not
> null)) or
> > > ABS> ((Old.Quantity is not null) and (New.Quantity is null))
> > > ABS> ) then
> > >
> > > Yaffil supports MS SQL-style == operator, i.e. yours code can be
> > > changed to
> > >
> > > if (Old.Quantity !== New.Quantity) then
> > >
> > > if I've not have mistaken.
> > >
> > > But, this is the question - will be == migrated from Yaffil to
> > > Firebird as other Yaffil features.
> >
> > Last time I was talking to Dmitry Emanov he told me this
> Yaffil piece
> > is still a little bit flacky to be ported into Firebird
> safely at the
> > moment.
> >
> > My opinion is that we should not go PostgreSQL way introducing 50+
> > custom operators made of all combinations of =, *, ~, ^, /,
> |, !, -,
> > ?, #, &, <, >, @ etc.
> >
> > Oracle way of adding built-in functions seems like better
> idea to me.
> > Something like MODIFIED(A, B) returning TRUE if A differs from B
> > considering null as a special value seems to look better.
>
> Now, this could easily be done if we had Stored Functions and
> typeless parameters ;-)

No really. This construct has to be matched to indices by optimizer.

> Martijn Tonies

Nickolay