leetcode-database-178. 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    |
+-------+------+

题意：给Scores表中分数排名，由高到低，相同分数排名相同，排名之间不能存在“洞”，要连续

思路 : 去重将score分数找出来，select distinct Score from Scores ->ranking

+---------+

| ranking  |  

+---------+

|    4.00   | 

|    3.85   | 

|    3.65   |

|    3.50   | 

+---------+

然后，将Scores表中的score和ranking比较，选择score<=ranking的记录数，即为rank

完整sql语句:

select Scores.Score, count(ranking.Score) as Rank

from Scores,

(select distinct Score from Scores) ranking

where Scores.Score <= ranking.Score

group by Scores.Id,Scores.Score

order by Scores.Score desc;