Thanks to you all, for your answers. I take it as if there is no
straight-forward SQL to do it, as you have to mess around with stored
procedures to make it work.

Interesting, though, that Oracle has support for such questions.

--- In firebird-support@yahoogroups.com, "Adam" <s3057043@...> wrote:
>
> The next step would be to define a recursive stored procedure. I
have
> not tested this, but I imagine it would look something similar to
below.