--子查询 查询last_name为chen的manager信息 select employee_id,last_name from employees where employee_id=( select manager_id from employees where last_name='Chen' )
运行结果
--查询 select employee_id,manager_id,department_id from employees where manager_id in( select manager_id from employees where employee_id in(141,147) ) and department_id in( select department_id from employees where employee_id in(141,147) ) and employee_id not in(141,174)
运行结果