Re: <> '' in PL/SQL

From: Michel Cadot <micadot_at_netcourrier.com>
Date: Tue, 14 Sep 1999 14:22:48 +0200
Message-ID: <7rleo6$atc$1@oceanite.cybercable.fr>

You have to change <> '' to is not null. As a matter of fact, '' is the same as NULL in PL/SQL so <> '' cannot be true and else part is execute.

v734>l
  1 declare
  2 abc varchar2(1);
  3 begin
  4 abc := 'a';
  5 if abc is not null then
  6 dbms_output.put_line(abc||' <> empty');   7 else
  8 dbms_output.put_line(abc||' = empty');   9 end if;
10* end;
v734>/
a <> empty

PL/SQL procedure successfully completed.

Norris a écrit dans le message <7rl8s6$4qs$1_at_adenine.netfront.net>...
>I am writing some simple PL/SQL , but I cannot intepret the result:
>
>set serveroutput on
>declare
>abc varchar2(1);
>begin
>abc := 'a';
>if abc <> '' then
> dbms_output.put_line(abc||' <> empty');
>else
> dbms_output.put_line(abc||' = empty');
>end if;
>end;
>
>
>The Result
>----------
>ServerOutput ON
>Statement processed.
>a = empty
>
>
>
>
>
>
>--
>- Have several nice days...
>- Opinions are mine and do not necessarily reflect those of the Corp.
>http://www.ntfaq.com
>http://www.cyberport.com/~tangent/programming/winsock/
Received on Tue Sep 14 1999 - 07:22:48 CDT