create or replace trigger t_emp_no
before insert on emp_info
begin
insert into emp_info(emp_no)
values(s_emp_no.nextval)
end;
/
i tried to entry primary key emp_no values without showing it on oracle 10g form with S_emp_no sequence .Problem is -i can't entry other rows value without primary key value, above trigger does not work. Can i get a solution ??

create or replace trigger t_emp_no
before insert on emp_info
for each row
when (new.empno is null)
begin
:new.emp_no := s_emp_no.nextval;
end;
/