连续获取MAX和MIN SQL

Question

;WITH CTE AS
(
    SELECT * FROM
    (
        SELECT CandidateID, t_Candidate.Name, ISNULL(CAST(AVG(Rate) AS DECIMAL(12,2)),0) AS Rate, t_Ambassadors.Name AS CN
        FROM t_Vote INNER JOIN t_Candidate 
        ON t_Vote.CandidateID = t_Candidate.ID
        INNER JOIN t_Ambassadors 
        ON t_Vote.AmbassadorID = t_Ambassadors.ID
        GROUP BY Rate, CandidateID, t_Candidate.Name, t_Ambassadors.Name
    )MySrc
    PIVOT
    (
        AVG(Rate)
        FOR CN IN ([Jean],[Anna],[Felicia])
    )AS nSrc

)SELECT CandidateID, Name, CAST([Jean] AS DECIMAL(12,2)) AS AHH ,CAST([Anna] AS DECIMAL(12,2)) AS MK,CAST([Felicia] AS DECIMAL(12,2)) AS DIL, CAST(([Jean] + [Anna] + [Felicia])/3 AS DECIMAL(12,2)) AS Total
FROM CTE
GROUP BY Cte.CandidateID, cte.Name, cte.[Jean], cte.[Anna], cte.[Felicia]

我用上面的查询解决了我以前的问题。 我创建了一个新问题，因为我遇到了新问题。 如何连续获得MAX和MIN速率？

以下是我从上面的查询得到的结果：

| CandidateID | Name |  AHH  |  MK  | DIL  | Total |
|-------------|------|-------|------|------|-------|
|     CID1    | Jay  | 7.00  | 3.00 | 3.00 | 4.33  |
|     CID2    | Mia  | 2.00  | 9.00 | 7.00 | 6.00  |

我想要实现的是：

| CandidateID | Name |  AHH  |  MK  | DIL  | Total |
|-------------|------|-------|------|------|-------|
|     CID1    | Jay  | 7.00  | 3.00 | 3.00 | 3.00  |
|     CID2    | Mia  | 2.00  | 9.00 | 7.00 | 7.00  |

所以在第二个结果发生的事情是，它从行中删除了最高和最低得分/率并得到剩余率/得分的平均值。 AHH，MK和DIL并不是唯一的选民，其中有14个，我只是先拿出3个选民，让它更短更清晰。

Answer 1

我相信你正在寻找类似下面的东西（虽然我使用的是案例聚合而不是支点）。

从本质上讲，它会对您的查询执行相同的操作，除了它使用行号来计算最高和最低值并将它们从最终的“总数”中排除（在平局的情况下，它只选择其中一个，但如果您不想在平均值中包含最高/最低值，则可以使用RANK()而不是row_number（）：

WITH CTE AS
(
    SELECT CandidateID,
           Name,
           CN,
           Rate,
           Lowest = ROW_NUMBER() OVER (PARTITION BY CandidateID, Name ORDER BY Rate),
           Highest = ROW_NUMBER() OVER (PARTITION BY CandidateID, Name ORDER BY Rate DESC)
    FROM
    (
        SELECT CandidateID,
               t_Candidate.Name,
               CN = t_Ambassadors.Name,
               Rate = ISNULL(CAST(AVG(Rate) AS DECIMAL(12,2)),0)
        FROM t_Vote
        JOIN t_Candidate
            ON t_Vote.CandidateID = t_Candidate.ID
        JOIN t_Ambassadors
            ON t_Vote.AmbassadorID = t_Ambassadors.ID
        GROUP BY CandidateID, t_Candidate.Name, t_Ambassadors.Name
    ) AS T
)
SELECT CandidateID,
       Name,
       AHH = MAX(CASE WHEN CN = 'Jean' THEN Rate END),
       MK = MAX(CASE WHEN CN = 'Anna' THEN Rate END),
       DIL = MAX(CASE WHEN CN = 'Felicia' THEN Rate END), -- and so on and so forth for each CN
       Total = AVG(CASE WHEN Lowest != 1 AND Highest != 1 THEN Rate END)
FROM CTE
GROUP BY CandidateID, Name;

编辑：有可能使用PIVOT做到这一点，但除非我弄错了，否则在转动之前计算出不是最高和最低的平均值的问题变得有点复杂。 使用案例聚合IMO更容易。