[LeetCode] Second Highest Salary

문제 : https://leetcode.com/problems/second-highest-salary/description/

 

풀이1. 서브쿼리 

SELECT 
	MAX(salary) AS SecondHighestSalary 
FROM (
    SELECT salary,
           DENSE_RANK() OVER (ORDER BY salary DESC) AS rnk
    FROM Employee
) ranked
WHERE rnk = 2;