查找每个类别的最佳和最差团队 - Oracle SQL

Question

我有一个场景，我需要找到最佳和最差的团队以及每个问题类别的得分。下面是输入表。

输出应为：

我尝试了查询，但无法找到最好和最差的团队。

SELECT QUESTION_CATEGORY,TEAM_NAME ,MIN(MARKS) WORST_SCORE,MAX(MARKS) BEST_SCORE, 
FROM QUESTIONS GROUP BY  QUESTION_CATEGORY,TEAM_NAME 

Answer 1

这可以使用row_numbers以升序和降序以及条件聚合来完成。

SELECT QUESTION_CATEGORY
,MAX(CASE WHEN RN_DESC=1 THEN TEAM_NAME END) AS BEST_TEAM
,MAX(CASE WHEN RN_DESC=1 THEN MARKS END) AS BEST_MARKS
,MAX(CASE WHEN RN_ASC=1 THEN TEAM_NAME END) AS WORST_TEAM
,MAX(CASE WHEN RN_ASC=1 THEN MARKS END) AS WORST_MARKS
FROM (SELECT QUESTION_CATEGORY,TEAM_NAME
      ,ROW_NUMBER() OVER(PARTITION BY QUESTION_CATEGORY ORDER BY MARKS) as RN_ASC
      ,ROW_NUMBER() OVER(PARTITION BY QUESTION_CATEGORY ORDER BY MARKS DESC) as RN_DESC
      FROM QUESTIONS
     ) T
GROUP BY QUESTION_CATEGORY

如果在最高/最低分数中可以存在关系，请在ORDER BY ROW_NUMBER函数中添加打破平局条件。

Answer 2

尝试使用此方法获得所需结果，而不使用子查询：

SELECT 
    QUESTION_CATEGORY,
    MIN(TEAM_NAME) KEEP (DENSE_RANK LAST ORDER BY MARKS) AS BEST_TEAM, 
    MIN(TEAM_NAME) KEEP (DENSE_RANK FIRST ORDER BY MARKS) AS WORST_TEAM, 
    MIN(MARKS) WORST_SCORE,
    MAX(MARKS) BEST_SCORE, 
FROM QUESTIONS 
GROUP BY QUESTION_CATEGORY;

请参阅FIRST文档

Answer 3

未经测试，但我会尝试这条道路：

select question_category, team_name, marks
from questions
where marks in (select max(marks) 
                from questions q1 
                where q1.question_category = questions.question_category)
or marks in (select min(marks) 
             from questions q1 
             where q1.question_category = questions.question_category)