一. 創建空表
create table dept_test as select * from scott.dept where rownum >1000;
二. 創建序列
--如果原表已經有數據, 則用max(**id)取得最大id值, 并以該值加1作為基值: start with max(**id)+1
create sequence dept_seq minvalue 1 maxvalue 100 start with 1 increment by 1 nocache;
三. 創建觸發器
create or replace trigger dept_trig
before insert on dept_test for each row
begin
select dept_seq.nextval into :new.deptno from dual;
end;
四. 抽取并插入數據
insert into dept_test(dname) select dname from scott.dept;