> 不用order by取第x大的xx, 按要求分组->组内有x条的是结果 ``` sql select s.emp_no, s.salary, e.last_name, e.first_name from salaries s join employees e on s.emp_no=e.emp_no and s.to_date='9999-01-01' and s.emp_no=(select s1.emp_no from salaries s1 join salaries s2 on s1.salary<=s2.salary and s1.to_date='9999-01-01' and s2.to_date='9999-01-01' group by s1.emp_no having count(1) = 2); ```