Hello

It must be an obvious thing I can't see because it's late Friday
afternoon...

Why does the last request return nothing ?


SQL> insert into ifa_security (PROGRAM_NAME) values ('TEST');

1 ligne créée.

SQL> select PROGRAM_NAME from ifa_security where PROGRAM_NAME = 'TEST';

PROGRAM_NAME
--------------------------------
TEST

1 ligne sélectionnée.

SQL> select PROGRAM_NAME from ifa_security where DML_CALLED = 'TEST';

aucune ligne sélectionnée

SQL> select PROGRAM_NAME from ifa_security where PROGRAM_NAME not in (select
DML_CALLED from ifa_security);

aucune ligne sélectionnée

SQL>



On the other hand,

SQL> select PROGRAM_NAME from ifa_security a where not exists (select 1 from
ifa_security where DML_CALLED = a.PROGRAM_NAME);

PROGRAM_NAME
--------------------------------
TEST

1 ligne(s) sélectionnée(s).



What's wrong with the NOT IN ?

Thank you !
Syltrem

On Fri, 26 Nov 2010 17:01:50 -0500, Syltrem wrote:

NULL values. See here:
http://articles.techrepublic.com.com...1-5319615.html



--
http://mgogala.freehostia.com

"Mladen Gogala" <gogala.mladen (AT) gmail (DOT) com> a écrit dans le message de news:
icpp5l$jam$8 (AT) solani (DOT) org...
Right.
I kind of remembered something about nulls but not quite, and I was not
expecting any nulls in the result set...

Thanks for that !
Syltrem