-- 使用自连接
select e.emp_no, s.salary, last_name, first_name
from employees e left join salaries s
on e.emp_no = s.emp_no
where e.emp_no = (
    select s1.emp_no
    from salaries s1 left join salaries s2
    on s1.salary <= s2.salary
    group by s1.emp_no
    having count(distinct s2.salary) = 2
)