Possible to write a function that takes any type as parameter ?

Question

I need to write a function that will take 2 parameters ( of any type - VARCHAR etc ) and return a boolean.
( Im trying to write a function that will do NULL processing.
something like..
if ( P1=P2 OR ( P1 IS NULL AND P2 IS NULL ) ) then
return true ;
end if;
return false ;
the function simply compares its parameters P1 & P2 and returns true if they are equal - including if both are NULL
Is this possible to write at all.
My code looks very ugly without this being wrapped in a function.

Answer 1

You may be able to use SYS.AnyData for this. However, dealing with the data would be confusing, so overloading the FUNCTION would most likely be a better idea.
This doesn't work, but it looked like fun, so i tried:
CREATE OR REPLACE FUNCTION Equal_Or_NULL(A SYS.AnyData, B SYS.AnyData)
RETURN PLS_INTEGER
AS
Local_A     VARCHAR2(4000);
Local_B     VARCHAR2(4000);
Junk          PLS_INTEGER;
BEGIN
IF A IS NULL AND B IS NULL THEN RETURN 1; END IF;
CASE A.GetTypeName
  WHEN 'SYS.NUMBER'     THEN Junk := A.GetNumber(Local_A); Junk := B.GetNumber(Local_B);
  WHEN 'SYS.DATE'     THEN Junk := A.GetDate(Local_A); Junk := B.GetDate(Local_B);
  WHEN 'SYS.CHAR'     THEN Junk := A.GetCHAR(Local_A); Junk := B.GetCHAR(Local_B);
  WHEN 'SYS.VARCHAR'     THEN Junk := A.GetVARCHAR(Local_A); Junk := B.GetVARCHAR(Local_B);
  WHEN 'SYS.VARCHAR2'     THEN Junk := A.GetVARCHAR2(Local_A); Junk := B.GetVARCHAR2(Local_B);
END CASE;
RETURN CASE WHEN Local_A = Local_B THEN 1 ELSE 0 END;
END Equal_Or_NULL;
/Overloading would be much simpler, as the arguments could be directly compared.
IMO, Do not do this. Hiding logic in a FUNCTION it for cosmetic purposes is a bad idea.