VALIDATION

DECLARE
   l_exists         CHAR (1);
   l_code_changed   CHAR (1);
BEGIN
   SELECT CASE
             WHEN EXISTS (SELECT *
                            FROM ITEM
                           WHERE NVL (menucode, 'null') = :menucode
                           AND itemid != :ITEMID and :ITEMID is not null) THEN 'Y'
             ELSE 'N'
          END
     INTO l_exists
     FROM DUAL;

   IF l_exists = 'Y' THEN
      RETURN FALSE;
   ELSE
      RETURN TRUE;
   END IF;
END;