[SQL]LeetCode178. 分數排名 | Rank Scores

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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    |
+-------+------+

---

編寫一個 SQL 查詢來實現分數排名。若是兩個分數相同，則兩個分數排名（Rank）相同。請注意，平分後的下一個名次應該是下一個連續的整數值。換句話說，名次之間不該該有「間隔」。

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

例如，根據上述給定的 Scores 表，你的查詢應該返回（按分數從高到低排列）：

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

---

137ms

1 # Write your MySQL query statement below
2 Select Score,
3 @rank:=@rank + (@pre<>(@pre:=Score)) as Rank
4 From Scores, (Select @rank:=0, @pre:=-1) INIT
5 Order by Score DESC;

---

139ms

1 # Write your MySQL query statement below
2 
3 select f.score Score, f.Rank from
4 (select 
5 @rnk:=@rnk + case when @score > s.score then 1 else 0 end as Rank
6 ,@score:= s.score as score
7 from 
8 (select score from scores order by score desc) s,(select @score:=0,@rnk:=1) t) f

---

142ms

1 # Write your MySQL query statement below
2 Select Score,
3 @rank:=@rank + (@pre<>(@pre:=Score)) as Rank
4 From Scores, (Select @rank:=0, @pre:=-2) INIT
5 Order by Score DESC;

---

143ms

1 # Write your MySQL query statement below
2 SELECT
3   Score,
4   @rank := @rank + (@prev <> (@prev := Score)) Rank
5 FROM
6   Scores,
7   (SELECT @rank := 0, @prev := -1) init
8 ORDER BY Score desc

---

146ms

1 # Write your MySQL query statement below
2 select Score, CONVERT(Rank, SIGNED) AS Rank from (
3 select Score,
4 if(Score = @previous_score, @rank := @rank, @rank := @rank +1) as Rank,
5 @previous_score := score
6 from Scores, (select @rank := 0, @previous_score:= null) r
7 order by Score desc)v

---

552ms

1 # Write your MySQL query statement below
2 
3 SELECT s.Score, count(distinct t.score) Rank
4 FROM Scores s JOIN Scores t ON s.Score <= t.score
5 GROUP BY s.Id
6 ORDER BY s.Score desc

---

553ms

1 # Write your MySQL query statement below
2 SELECT s1.Score, count(distinct s2.Score) as Rank
3 FROM Scores s1 
4     join Scores s2 on s1.Score <= S2.Score
5 GROUP BY s1.Id
6 ORDER BY 2