Rank Scores

Write a SQL query to rank scores. If there is a tie between two scores, both should have the same ranking. Note that after a tie, the next ranking number should be the next consecutive integer value. In other words, there should be no "holes" between ranks.

+----+-------+
| Id | Score |
+----+-------+
| 1  | 3.50  |
| 2  | 3.65  |
| 3  | 4.00  |
| 4  | 3.85  |
| 5  | 4.00  |
| 6  | 3.65  |
+----+-------+
 
For example, given the above Scores table, your query should generate the following report (order by highest score):
+-------+------+
| Score | Rank |
+-------+------+
| 4.00  | 1    |
| 4.00  | 1    |
| 3.85  | 2    |
| 3.65  | 3    |
| 3.65  | 3    |
| 3.50  | 4    |
+-------+------+
 
目前给出的方案只能排序,而且有hole:
select s1.Score, (select count(1)+1 from Scores as s2  where s2.Score > s1.Score )as Rank from Scores  as s1 order by s1.Score desc;

+-------+------+
| Score | Rank |
+-------+------+
|  4.00 |    1 |
|  4.00 |    1 |
|  3.85 |    3 |
|  3.65 |    4 |
|  3.65 |    4 |
|  3.50 |    6 |
+-------+------+

select s1.Score, (select count(distinct s2.Score) from Scores as s2  where s2.Score > s1.Score ) + 1 as Rank from Scores  as s1 order by s1.Score desc ;

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

posted @ 2015-03-04 22:34  当数据爱上科学  阅读(311)  评论(0编辑  收藏  举报