Select with Where not in (subSelect)

Question

Hi,
Is there any special about that 'not' in this ORacle sql (10g) that it doesn't return me any rows, unlike SQLServer with same code:
select count(*) from t1_ups where  id_ups not in (select b.id_ups from t1_dups b)
COUNT(*)              
0
vs.
select count(*) from t1_ups where  id_ups not in ('abc', 'def','xyz')  --select b.id_ups from t1_dups b)
COUNT(*)              
16
DDL:
    "id_ups"            VARCHAR2(20 BYTE),   is the same for both tables.I see that if remove <not> it works fine. is there any OR --> AND converssion happaned with negation?
My global task is to make UNION "with replacement" when if any records exist in id_dups they will replace ones from id_ups, so I try to do it in separate parts.
Thanks
Tr
Edited by: trento on Nov 16, 2010 3:00 PM

Answer 1

trento wrote:
Hi,
Is there any special about that 'not' in Yes, you need to be aware how the syntax reacts to NULL values.
create table in_or_not
  col1  number
TUBBY_TUBBZ?insert into in_or_not values (2);
1 row created.
Elapsed: 00:00:00.05
TUBBY_TUBBZ?select 1 from dual where 1 not in (select col1 from in_or_not);
                 1
                 1
1 row selected.
Elapsed: 00:00:00.00
TUBBY_TUBBZ?insert into in_or_not values (NULL);
1 row created.
Elapsed: 00:00:00.00
TUBBY_TUBBZ?select 1 from dual where 1 not in (select col1 from in_or_not);
no rows selected
Elapsed: 00:00:00.01http://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:442029737684