Temmelig sikker på, at du skal gøre dette med en trigger i Oracle:
create or replace TRIGGER parkedorder_tbiur
BEFORE INSERT OR UPDATE
ON parkedorder
REFERENCING OLD AS old_row NEW AS new_row
FOR EACH ROW
BEGIN
IF INSERTING
THEN
IF :new_row.ID IS NULL
THEN
SELECT parkedorder_seq.NEXTVAL
INTO :new_row.ID
FROM DUAL;
END IF;
END IF;
IF :new_row.lastupdated <> SYSDATE
OR :new_row.lastupdated IS NULL
THEN
SELECT sysdate
INTO :new_row.lastupdated
FROM DUAL;
END IF;
SELECT SYS_CONTEXT ( 'USERENV', 'OS_USER' )
INTO :new_row.lastupdatedby
FROM DUAL;
END;