連續獲取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]

我用上面的查詢解決了我以前的問題。 我創建了一個新問題，因為我遇到了新問題。 如何連續獲得MAX和MIN速率？

以下是我從上面的查詢得到的結果：

| 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  |

我想要實現的是：

| 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  |

所以在第二個結果發生的事情是，它從行中刪除了最高和最低得分/率並得到剩余率/得分的平均值。 AHH，MK和DIL並不是唯一的選民，其中有14個，我只是先拿出3個選民，讓它更短更清晰。

Answer 1

我相信你正在尋找類似下面的東西（雖然我使用的是案例聚合而不是支點）。

從本質上講，它會對您的查詢執行相同的操作，除了它使用行號來計算最高和最低值並將它們從最終的“總數”中排除（在平局的情況下，它只選擇其中一個，但如果您不想在平均值中包含最高/最低值，則可以使用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;

編輯：有可能使用PIVOT做到這一點，但除非我弄錯了，否則在轉動之前計算出不是最高和最低的平均值的問題變得有點復雜。 使用案例聚合IMO更容易。