Custom dialect, use of case

[Matthijs ter Woord]

Hi!

I'm trying to make a custom dialect for interbase. When using either the Firebird one as base, or a ported version of the Hibernate interbase dialect, I get situations where case when is used for comparing Datetime fields.
See SQL:
         CASE
                  WHEN Cast(
                           CASE
                                    WHEN afmeldinge0_.datum_van IS NULL THEN ?
                                    ELSE afmeldinge0_.datum_van
                           END AS TIMESTAMP)>? THEN 1
                  ELSE 0
         END=?

Is there a way to influence what gets generated?

Thanks!

With kind regards,
Matthijs ter Woord