오라클에서 ISNUMERIC 함수구현하기

CREATE OR REPLACE FUNCTION ISNUMERIC(i_str VARCHAR2) RETURN NUMBER

IS

 v_ret NUMBER;

BEGIN

  IF i_str IS NULL OR LENGTH(TRIM(i_str)) = 0 THEN

    RETURN 0;

  END IF;

 

  V_RET := TO_NUMBER(I_STR);

  RETURN 1;

 

EXCEPTION WHEN OTHERS THEN

  RETURN 0;

END ;