如何迭代此SQL查询？

Question

我有这个问题：

SELECT TOP 1 A.ExamTemplateId, A.Id AS AnsweredTestId, AVG(B.Score) AS AvgScore, A.[Date]
FROM AnsweredTest AS A
INNER JOIN AnsweredWorksheet AS B ON (A.Id = B.AnsweredTestId)
WHERE A.StudentId = 'OPA-3DKCL2' AND A.ExamTemplateId = 1
GROUP BY A.Id, A.ExamTemplateId, A.[Date]
ORDER BY AvgScore DESC

请检查我的WHERE条件是否收到静态编号。查询结果为：

示例1

示例2

这是正确的！但现在，我想显示ExamTemplate表中的所有记录。但现在我不知道如何实现这一目标。我在想创建一个函数，但我不确定，这只是一个想法。

我想收到的最终结果是最后记录的结合：

1   1   0.7 2012-10-21 19:50:11.697
2   10  0.555555555555556   2012-10-22 18:58:24.163

提前致谢。

更新：

我用黄色突出显示了我感兴趣的行。我在最后一个查询TOP 1中设置了因为我想获得ExamTemplateId的最高平均分数。这就是全部。

Answer 1

听起来您想要用值列表替换A.ExamTemplateId = 1。如果是这样，那么你应该可以使用类似于以下内容的东西：

SELECT A.ExamTemplateId, 
  A.Id AS AnsweredTestId, 
  AVG(B.Score) AS AvgScore, 
  A.[Date]
FROM AnsweredTest AS A
INNER JOIN AnsweredWorksheet AS B 
  ON (A.Id = B.AnsweredTestId)
WHERE A.StudentId = 'OPA-3DKCL2' 
  AND A.ExamTemplateId IN (SELECT ExamTemplateId -- use a SELECT statement to get all template id
                           FROM ExamTemplateTable)
GROUP BY A.Id, A.ExamTemplateId, A.[Date]
ORDER BY AvgScore DESC

如果您只想要一个值，那么您可以使用以下内容：

select ExamTemplateId,
    AnsweredTestId,
    AvgScore,
    [Date]
from 
(
  select ExamTemplateId,
    AnsweredTestId,
    AvgScore,
    [Date],
    row_number() over(partition by ExamTemplateId order by AvgScore) rn
  from
  (
    SELECT A.ExamTemplateId, 
      A.Id AS AnsweredTestId, 
      AVG(B.Score) AS AvgScore, 
      A.[Date]
    FROM AnsweredTest AS A
    INNER JOIN AnsweredWorksheet AS B 
      ON (A.Id = B.AnsweredTestId)
    WHERE A.StudentId = 'OPA-3DKCL2' 
      AND A.ExamTemplateId IN (SELECT ExamTemplateId -- use a SELECT statement to get all template id
                               FROM ExamTemplateTable)
    GROUP BY A.Id, A.ExamTemplateId, A.[Date]
  ) sc
) mx
where rn = 1

Answer 2

使用分区。

With t AS (
    SELECT A.ExamTemplateId, A.Id AS AnsweredTestId, AVG(B.Score) AS AvgScore, A.[Date] 
    FROM AnsweredTest AS A
    INNER JOIN AnsweredWorksheet AS B ON (A.Id = B.AnsweredTestId)
    WHERE A.StudentId = 'OPA-3DKCL2' --AND A.ExamTemplateId in (...)
    GROUP BY A.Id, A.ExamTemplateId, A.[Date]
)
, w AS (
    SELECT *, 
        ROW_NUMBER() OVER (PARTITION BY ExamTemplateId ORDER BY AvgScore DESC) rank
    FROM t 
)
SELECT * FROM w 
WHERE rank = 1

Answer 3

起初我以为你想看到所有的学生，但我想你想要超过所有考试模板 - 任何理由你不能只删除前1个过滤器并从中取出考试模板？ 平均值将按照考试模板计算，我想你想要的是什么。

SELECT A.ExamTemplateId, A.Id AS AnsweredTestId, AVG(B.Score) AS AvgScore, A.[Date]
FROM AnsweredTest AS A
INNER JOIN AnsweredWorksheet AS B ON (A.Id = B.AnsweredTestId)
WHERE A.StudentId = 'OPA-3DKCL2' 
GROUP BY A.Id, A.ExamTemplateId, A.[Date]
ORDER BY AvgScore DESC`