这个提的解题思路和老二那道题的思路一样，利用 row_number 解决
零、解析
首先去除数据中相同的工资，然后将工资从大到小排序，接着利用 row_number 函数给每行数据加上行号，最后过滤出行号为N的工资，因为需要根据指定的排名查询，因此这里用到了函数。代码如下：
代码语言：javascript复制CREATE FUNCTION getNthHighestSalary(@N INT) RETURNS INT AS
BEGIN
RETURN (
/* Write your T-SQL query statement below. */
select NULLIF((select Salary from (select Salary,row_number() over(order by Salary desc) as rn from (select distinct Salary from Employee)as e) as demo where rn=@N),null) as SecondHighestSalary
);
END
