orcal中id自增

創建序列
create sequence （序列的名稱） start with (開始時間) increment by (步長)

創建觸發器
create or replace trigger (觸發器的名稱)
before insert on (表名)
for each row
begin
select (序列的名稱).nextval into :new.id from dual;
end;
實例代碼：

--創建序列
create sequence obj_status_change_seq start with 1 increment by 1;
--創建觸發器
create or replace trigger obj_status_change_trigger
before insert on obj_status_change
for each row
begin
select obj_status_change_seq.nextval into :new.id from dual;
end ;