Re: PL/SQL: handling of empty string (strange)

"stephan" <stephan0h_at_yahoo.de> a écrit dans le message de news:af65e20e.0403110647.746a12bc_at_posting.google.com...
> Hi everybody,
>
> I've got this code-sample here which puzzles me:
>
> declare
> s VARCHAR2(1):='S';
> begin
> dbms_output.put_line(s);
> if s!='' then
> dbms_output.put_line('hoppla');
> else
> dbms_output.put_line('ballaballa');
> end if;
> end;
> /
>
> When run the program enters the else-branch. But why - 'S'!='' must
> certainly be true!?
>
> Thanks,
> Stephan

As we said it here many and many times '' is NULL, so 'S' != '' is equivalent to 'S' != NULL which is NEVER true.

Regards
Michel Cadot Received on Thu Mar 11 2004 - 09:09:21 CST