一. 創(chuàng)建空表
create table dept_test as select * from scott.dept where rownum >1000;
二. 創(chuàng)建序列
--如果原表已經(jīng)有數(shù)據(jù), 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(chuàng)建觸發(fā)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(shù)據(jù)
insert into dept_test(dname) select dname from scott.dept;