Question

我有下表：

Class, Name, Score
1, Anna, 34
1, Andy, 80
2, Brooke, 90
2, Brad, 70
3, Charles, 67
3, Christina, 66

如何在每个“班级”中找到“最高分数”的“姓名”？

必需输出：

Class, Name, Score
1, Andy, 80
2, Brooke, 90
3, Charles, 67

这是针对MySQL的。

Answer 1

WITH ClassScores AS
(
    SELECT 1 AS class, 'Anna' AS name, 34 AS score 
    UNION
    SELECT 1, 'Andy', 80  
    UNION
    SELECT 2, 'Brooke', 90  
    UNION
    SELECT 2, 'Brad', 70  
    UNION
    SELECT 3, 'Charles', 67  
    UNION
    SELECT 3, 'Christina', 66 
)

SELECT C1.Class, C1.Name, C1.Score
  FROM ClassScores AS C1
  JOIN (SELECT Class, MAX(Score) AS MaxScore
          FROM ClassScores
         GROUP BY Class
       ) AS C2
    ON C1.Class = C2.Class
   AND C1.Score = C2.MaxScore
 ORDER BY C1.Class;

Answer 2

另一种方式 - 如果ClassScores有（隐藏）PRIMARY KEY：

SELECT 
    cs.Class
  , cs.Name
  , cs.Score
FROM 
      ( SELECT DISTINCT Class 
        FROM ClassScores 
      ) AS csd
  JOIN 
      ClassScores AS cs
    ON cs.PK = 
       ( SELECT csm.PK
         FROM ClassScores csm
         WHERE csm.Class = csd.Class
         ORDER BY csm.Score DESC
         LIMIT 1
       )

Answer 3

使用UNION然后您可以单独使用三个select语句。它会很好地清理代码。

尝试..

select class, name, max(score) as "Score" from yourTable where class=1
UNION
select class, name, max(score) as "Score" from yourTable where class=2
UNION
select class,name,max(score) as "Score" from yourTable where class=3

在SQL中查找具有最大值的记录

3 个答案: