SQL> create sequence a_sequence
2 start with 1
3 increment by 1;
序列已创建。
SQL> create table t (n number ,v varchar2(10));
表已创建。
SQL> create or replace trigger t_trg
2 before insert or update on t
3 for each row
4 begin
5 select a_sequence.nextval into :new.n from dual;
6 end;
7 /