ListField items from SQL method

Hi,

I'm new to this list and the archive seems to be incomplete so please do
not throw anything on me if this question was asked in the past. ;-)

I recently detected Zope Formulator and I like it very much.  Normally
this ends up in feature requests. ;-)  So I would live if I would be able
to provide the Items for a ListField by calling an SQL method.  The
rationale behind this is that I want to build a form to query a database
and the user should select some predefined items from this data base.
It would be really stupid if I would have to copy those items from
the database to the Formulator Items because this would end in a mess
when updating the database.

Kind regards and thanks for this fine Zope product

        Andreas.