对所有员工的薪水按照salary降序进行1-N的排名

# select emp_no,
#         salary,
#         dense_rank()over(order by salary desc)as't_rank'
#         from salaries
select s1.emp_no,
        s1.salary,
        count(distinct s2.salary)as't_rank'
        from salaries s1
        join salaries s2
        on s1.salary<=s2.salary
        group by s1.emp_no,s1.salary
        order by t_rank,emp_no