Fritz,

> I've used the correct view syntax. However, I think I
> might have some problem with my setup.
>
> When I'm trying
>
> select truncate(fTarif) from "MyTable"
>
> I get the error message:
>
> Dynamic SQL Error.
> SQL error code = -804.
> Function unknown.
> TRUNCATE.
>
> Same thing for:
>
> select abs(-1) from rdb$database;
>
> An error was found in the application program input
> parameters for the SQL statement.
> Dynamic SQL Error.
> SQL error code = -804.
> Function unknown.
> ABS.
>
> It looks like I can't use any external function. Do I
> have to enable those explicitly somewhere?

Yes, you have to "declare" external functions on a per
database basis.

Somewhere in your Firebird install, there should be
something like "fbudf.sql" - a script file that declares
all functions for you.

Martijn Tonies
Database Workbench - development tool for Firebird and more!
Upscene Productions
http://www.upscene.com
My thoughts:
http://blog.upscene.com/martijn/
Database development questions? Check the forum!
http://www.databasedevelopmentforum.com