178. Rank Scores

题目链接：

178. Rank Scores

解析：

刚开始看到这道题我的写法是这样的：

SELECT Score,
    (SELECT COUNT(*) FROM Scores S1 WHERE S1.Id != S2.Id AND S1.Score >= S2.Score) AS Rank
FROM Scores S2
ORDER BY Rank;

但是这样的输出Rank结果为：1,1,2,4,4,5。不满足题目要求，所以这里我们应该使用DISTINCT关键字来进行处理。

题解：

# Write your MySQL query statement below
SELECT Score, 
    (SELECT COUNT(DISTINCT Score) FROM Scores S1 WHERE S1.Score >= S2.Score) AS Rank 
FROM Scores S2
ORDER BY Rank;