MySQL/178. Rank Scores 分数排名

题目

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代码部分一（1537ms）

SELECT
    Score,(SELECT COUNT(DISTINCT Score) FROM Scores s2 WHERE s2.Score>=s1.Score) AS Rank
    FROM Scores s1
    ORDER BY Rank 

 

代码部分二（910ms）

SELECT 
    s1.Score,COUNT(DISTINCT s2.Score) AS Rank
    FROM Scores s1
    JOIN Scores s2 ON s2.Score>=s1.Score
    GROUP BY s1.Id
    ORDER BY s1.Score DESC;

 

代码部分三（890ms）

SELECT
    Score,(SELECT COUNT(DISTINCT Score) FROM Scores s2 WHERE s2.Score>=s1.Score) AS Rank
    FROM Scores s1
    ORDER BY Score DESC 

 

代码部分四（419ms）

SELECT
    s.Score,Count(Ranking.Score) AS Rank
    FROM Scores s,(
        SELECT DISTINCT Score
        FROM Scores
        ) AS Ranking
    WHERE Ranking.Score>=s.Score
    GROUP BY s.id
    ORDER BY s.Score DESC

 

代码部分五（251ms）

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;

代码部分六（160ms）

SELECT Score, CONVERT ( CASE 
    WHEN @preValue = Score THEN @preRank
    WHEN (@preValue := Score) >= 0 THEN @preRank := @preRank + 1
END, UNSIGNED) AS Rank
FROM Scores, (SELECT @preValue := NULL) p, (SELECT @preRank := 0) v
ORDER BY Score DESC;