--创建表
create table emp01
as
select * from employees
where department_id in (70,80)--
--创建表
create table emp02
as
select * from employees
where department_id in (80,90)
--查询 --并集
select * from employees
where department_id in (70,80)
union all
select * from employees
where department_id in (80,90)