def by_person_birthdate_key(self, handle):
"""Compare by birth date, if equal sorts by name."""
obj = self.query_method(handle)
birth = get_birth_or_fallback(self.database, obj)
if birth:
date = birth.get_date_object()
else:
date = Date()
return "%08d" % date.get_sort_value() + str(
self.by_person_surname_key(handle))
