DO $$
BEGIN
  ALTER TABLE CLIENTE ADD (ISESTRANGEIRO NUMBER(1,0));
  EXCEPTION
  WHEN OTHERS THEN NULL;
  WHEN unique_violation THEN NULL;
END
$$;
/
DO $$
BEGIN
  ALTER TABLE CLIENTE_DIRECCION ADD (DESCPAIS VARCHAR2(60 BYTE));
  EXCEPTION
  WHEN OTHERS THEN NULL;
  WHEN unique_violation THEN NULL;
END
$$;
/