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Home -> Community -> Mailing Lists -> Oracle-L -> Re: IN ignore null values
It works exactly as I expected.
It proves that null is never equal to an arbitrary column, and that
there is 100 rows in x.
15:20:50 rsysdevdb.radisys.com - jkstill_at_dv01 SQL> drop table x;
Table dropped.
15:20:50 rsysdevdb.radisys.com - jkstill_at_dv01 SQL> 15:20:50 rsysdevdb.radisys.com - jkstill_at_dv01 SQL> create table x 15:20:50 2 as 15:20:50 3 select owner, table_name, tablespace_name 15:20:50 4 from dba_tables 15:20:50 5 where rownum <= 100 15:20:50 6 /
Table created.
15:20:50 rsysdevdb.radisys.com - jkstill_at_dv01 SQL> 15:20:50 rsysdevdb.radisys.com - jkstill_at_dv01 SQL> select count(*) 15:20:50 2 from x 15:20:50 3 where table_name in ( 15:20:50 4 select null from x 15:20:50 5 ) 15:20:50 6 /
COUNT(*)
0
1 row selected.
15:20:50 rsysdevdb.radisys.com - jkstill_at_dv01 SQL> 15:20:50 rsysdevdb.radisys.com - jkstill_at_dv01 SQL> select count(*) 15:20:50 2 from x 15:20:50 3 where exists ( select null from x ) 15:20:50 4 /
COUNT(*)
100
1 row selected.
15:20:50 rsysdevdb.radisys.com - jkstill_at_dv01 SQL>
"Juan Cachito Reyes Pacheco" <jreyes_at_dazasoftware.com>
Sent by: oracle-l-bounce_at_freelists.org
02/20/2004 10:48 AM
Please respond to oracle-l
To: <oracle-l_at_freelists.org>
cc:
Subject: Re: IN ignore null values
I don't understand what is not clear here, you can test it by yourself. :)
Actually, all this proves is that you have 310 rows in the table
utl_tablas_me.
Jared
An interesting observation
IN ignore null values as you can see in the table there are 310 null
values
in column TBL_DSM.
SQL> select count(*) from daz.utl_tablas_me
2 where tbl_dsm in
3 (select null from daz.utl_tablas_me);
COUNT(*)
0
SQL> select count(*) from daz.utl_tablas_me
2 where exists(select null from daz.utl_tablas_me);
COUNT(*)
310
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