--- In firebird-support@yahoogroups.com, "Ivan Prenosil"
<Ivan.Prenosil@...> wrote:

>
> It seems you are looking at wrong table:
> CREATE TABLE KATEG_ORIGINAL (
> vs.
> WHERE (rel.RDB$Relation_Name = 'KOMP_ORIGINAL')

That's only a copy-error when I wrote my message. The tables
'Komp_Original' and 'Kateg_Original' have the very same structure.

>
> The correct flag must be in rel.RDB$Null_Flag
>
> Ivan
> http://www.volny.cz/iprenosil/interbase/
>

In my first post I wrote:

> > I get the same wrong result with "rel.RDB$Null_Flag" instead of
> > "fld.RDB$Null_Flag".

Is it possible that Firebird sets the not-null-Flag via
RDB$xxx_Constraints? All the fields to that
RDB$Relation_Fields.RDB$Null_Flag show false values are used by
PrimaryKeys, ForeignKeys or not-null-Checks (directly in Create-Table
or indirectly by Domain).

If it's necessary to read the Constraints-Tables could someone give a
select command with all field properties?

Thanks! Juergen

PS. I tried to answer via my e-mail programm. But I'm not able to do
so because yahoo refused any text markings. Qrrr...