Oracle equivalent of DB2 DIGITS function

Question

IBM DB2 has a DIGITS SQL function that returns a character-string representation of a number, with the following properties:
The result of the function is a fixed-length character string representing the absolute value of the argument without regard to its scale. The result does not include a sign or a decimal character. Instead, it consists exclusively of digits, including, if necessary, leading zeros to fill out the string.
For example, for a NUMBER(6,2) column with value -6.28, the string '000628' is returned.
Is there an equivalent SQL function available in Oracle 10g? Or if there's no equivalent, how can this be done in Oracle 10g?

Answer 1

So, looks like behavior of DIGITS function depends not only on the value of the parameter passed, but also on the datatype of the actual parameter (implicitly derived from the datatype of the column name being passed).
In other words, you can not simply call DIGITS (-6.18) because the result could be different for different precision/scale combinations:
NUMBER(6,2) -> 000618
NUMBER(3,2) -> 618
NUMBER(6,3) -> 006180
I don't think Oracle has a mechanism of accessing the datatype of the actual argument from within the function (?)
So, you would need to pass the precision and scale of the argument datatype separately:
create or replace function digits (n number, precision number, scale number) return varchar2 as
begin
return lpad (abs(n)*power(10,scale),precision, '0');
end;
SQL> select digits (-6.18, 6, 3) from dual;
006180
SQL> select digits (-6.18, 3,2) from dual;
618
SQL> select digits (-6.18, 6,2) from dual;
000618
To replace DIGITS in your DB2 code, you would need to build a conversion that would look up the precision and scale of the column for each call and substitute them into the call accordingly.