In Oracle Null=null ? ---- False

In Oracle Null is not equal to null :) !!!!!!!!!!



select case when null = null
then 1 ----true
else 2 ----flase
end
from dual ;

CASEWHENNULL=NULLTHEN1----TRUEELSE2----FLASEEND
-----------------------------------------------
2 ---- so false


so you can not equate the null with null ( null=null) --<<--- false





select decode(null,null, 1, 2) from dual; --<<<<--- in decode

DECODE(NULL,NULL,1,2)
---------------------
1 <<<---- true





select case when null = null
then 1
else 2
end "Case",
decode(null,null, 1, 2) "Decode" from dual
SQL> /

Case Decode
---------- ----------
2 1






SELECT * FROM dual WHERE NULL = NULL;

No rows selected.

SELECT * FROM dual WHERE NULL <> NULL;

No rows selected.