面试题：分数排名

难度：中等

写一段SQL语句查询分数排名情况。如果两个分数相等，则排名相同。

+----+-------+
| Id | Score |
+----+-------+
| 1  | 3.50  |
| 2  | 3.65  |
| 3  | 4.00  |
| 4  | 3.85  |
| 5  | 4.00  |
| 6  | 3.65  |
+----+-------+

例如：按上表 Scores 的数据， 你的查询语句返回下列数据（从大到小排序）:

+-------+------+
| Score | Rank |
+-------+------+
| 4.00  | 1    |
| 4.00  | 1    |
| 3.85  | 2    |
| 3.65  | 3    |
| 3.65  | 3    |
| 3.50  | 4    |
+-------+------+

 

答案：

select a.Score, (select count(distinct Score) from Scores where Score>=a.Score) as Rank 
from Scores a
order by a.Score desc