Function to check whether a value is NUMERIC

Question

Hi
I have a requirment, where I need to check for a field whether it contains a valid numeric value or not.
Could you please suggest a function.
If I use TO_NUMBER(VAL1) it throws an exception in case of an non_numeric value.
The requirement is as follows.
If the field 'val1' contains a numeric value then the function should return the coressponding nueric value. If it is not,then return a boolean value are a return code instead of exception.
Is there are built in function in ORACLE to acheive the same , please advice.

Answer 1

Hi,
The best way to do it is using User Defined Function, i have written a function as per your Requirement...It is give the data if it is numeric else it will return FALSE
create table Testdata
as
select '10' n from dual
union all
select 'xx' from dual
union all
select '20' from dual
union all
select '3YY' from dual;
CREATE OR REPLACE FUNCTION IsNumeric
(p_col_value IN VARCHAR2)
RETURN     VARCHAR2
AS
v_val NUMBER;
BEGIN
v_val := TO_NUMBER (p_col_value);
RETURN 'TRUE';
EXCEPTION
WHEN VALUE_ERROR THEN
          RETURN 'FALSE';
     WHEN OTHERS THEN
          RETURN 'FALSE';
END IsNumeric;
Select Decode(IsNumeric(n),'TRUE',n,'FALSE') from Testdata
Regards
kamal