思路：分别得到构建员工工资表和管理工资表，再多表查询比较
第一：得到员工工资表，管理工资表：员工表dept_emp和manager表dept_manager分别与工资表salaries内连接，得员工工资表，管理工资表
第二：员工工资表 > 管理工资表
运用：内联结
select a.emp_no,b.emp_no as manager_no,a.salary as emp_salary,b.salary as manager_salary
from (select de.emp_no,de.dept_no,s.salary
from dept_emp de inner join salaries s
on de.emp_no=s.emp_no
and s.to_date='9999-01-01'
and de.to_date='9999-01-01') as a
inner join
(select dm.emp_no,dm.dept_no,s.salary
from dept_manager dm inner join salaries s
on dm.emp_no=s.emp_no
and s.to_date='9999-01-01'
and dm.to_date='9999-01-01') as b
on a.dept_no=b.dept_no
and a.salary>b.salary;