oracle表的删除与恢复

create table dept(
  dept_no number primary key,
  dept_name varchar2(100)
);
create table emp(
  emp_no number,
  emp_name varchar2(100),
  dept_no number constraint fk_emp_dept_no references dept(dept_no)
);
insert into dept values(1,'软件三部');
insert into dept values(2,'软件四部');
insert into emp values(1,'张三',1);
insert into emp values(2,'李四',2);
commit;
select t.*, t.rowid from dept t;
select t.*, t.rowid from emp t;

drop table dept cascade constraints;
drop table dept cascade constraints purge;
drop table emp;

flashback table emp to before drop;
select object_name,original_name,type from user_recyclebin;
purge recyclebin;