# 死方法:3表相连(外层from, 内层 join) select a.emp_no, b.emp_no, a.salary, b.salary from (-- 员工 工资 select de.emp_no, salary, de.dept_no from dept_emp de inner join salaries s on de.emp_no = s.emp_no where de.to_date='9999-01-01' and s.to_date='9999-01-01' ) as a, (-- 领导 工资 select dm.emp_no, salary, dm.dept_no from dept_manager dm inner join salaries s on dm.emp_no = s.emp_no where dm.to_date='9999-01-01' and s.to_date='9999-01-01' ) as b where a.dept_no=b.dept_no and a.emp_no<>b.emp_no and a.salary>b.salary