LeetCode题库 - 第N高的薪水

# 创建函数之前需要制定一个参数
set global log_bin_trust_function_creators=TRUE;

# 创建函数
CREATE FUNCTION getNthHighestSalary(n INT) RETURNS INT
BEGIN
   DECLARE s INT; 
   SET s = n-1;
   RETURN(
       select IFNULL((select distinct Salary from Employee1 order by  Salary desc limit s, 1), null) as getNthHighestSalary
         );
END;

# 调用自定义函数
SELECT getNthHighestSalary(2);