题解 | #获取每个部门中当前员工薪水最高的相关信息#
获取当前薪水第二多的员工的emp_no以及其对应的薪水salary
http://www.nowcoder.com/practice/c1472daba75d4635b7f8540b837cc719
先找到最大薪水
select max(salary) from salaries where to_date = '9999-01-01'
然后将上面的结果作为一个条件，查找第二大！
select max(salary) from salaries where to_date = '9999-01-01' and salary < (select max(salary) from salaries where to_date = '9999-01-01')
最后联结两个表就可以得到想要的结果！
SELECT a.emp_no, b.salary,a.last_name,a.first_name from employees a inner join salaries b
on a.emp_no = b.emp_no
where to_date = '9999-01-01'
and b.salary =
(
select max(salary) from salaries where to_date = '9999-01-01'
and salary < (select max(salary) from salaries where to_date = '9999-01-01')
)