--- In firebird-support@yahoogroups.com, "Alexander V.Nevsky"
<ded@h...> wrote:

> for select id,something from wtreestore into :id, :something do
> begin
> update demo D1 set D1.something =
> (select first 1 D2.something from demo D2 where
> D2.id < D1.id order by id desc)
> )
> where D1.id = :id;
> end

Hmm, in hurry wrote ambigious query myself :) Note non-aliased
usage of ID in order by of subselect. IMO decision to don't force
ambiguity checking in dialect 1 for compatibilty with old applications
makes more harm than benefit.

Best regards,
Alexander.