check if “it's a number” function in Oracle

Question

I\'m trying to check if a value from a column in an oracle (10g) query is a number in order to compare it. Something like:

select case when ( is_number(myTab         


        

Answer 1

CREATE OR REPLACE FUNCTION is_number(N IN VARCHAR2) RETURN NUMBER IS
  BEGIN
    RETURN CASE regexp_like(N,'^[\+\-]?[0-9]*\.?[0-9]+$') WHEN TRUE THEN 1 ELSE 0 END;
END is_number;

Please note that it won't consider 45e4 as a number, But you can always change regex to accomplish the opposite.