Simple PL/SQL function to test if a string is a number

Question

I\'m experienced with T-SQL from SQL Server, but have recently begun working on a project utilizing an Oracle database (11g) and am having some issues writing what seems to

Answer 1

Return a SQL datatype, e.g. VARCHAR2. Also, I'd recommend against using WHEN OTHERS. Also, you don't need a query on dual:

create or replace 
function IS_NUMBER(str in varchar2) return varchar2
IS
  n number;
BEGIN
  n := to_number(str);
  return 'Y';
EXCEPTION WHEN VALUE_ERROR THEN
  return 'N';
END;