使用where筛选掉最大值，再从剩下的找出最大值
with a as(
select e.emp_no,s.salary,e.last_name,e.first_name
from employees e
left join salaries s on e.emp_no = s.emp_no
where s.salary != (select max(salary) from salaries)
)
select emp_no,salary,last_name,first_name
from a 
where salary = (select max(salary) from a)