trigger in Oracle.
Trigger used in apex
create or replace trigger myTableTrigger
before insert or update on myTable
for each row
begin
if inserting then
if :new.myPk is null then
select mySequence.nextval into :new.myPk from dual;
end if;
:new.created_on := systimestamp;
:new.created_by := nvl(v('APP_USER'),nvl(sys_context('userenv','os_user'),user));
:new.
elsif updating then
:new.updated_on := systimestamp;
:new.updated_by := nvl(v('APP_USER'),nvl(sys_context('userenv','os_user'),user));
end if;
end;
/