需要 Median 来关注 Group By Case答案

【问题标题】：Need Median to follow Group By Case需要 Median 来关注 Group By Case
【发布时间】：2017-05-22 18:38:16
【问题描述】：

我想知道是否可以在为每个 DonorType 组运行中值计算时获得一些帮助。通过查询，我得到的只是所有值的中位数，而不是每个案例分组的值。我尝试了几件事并环顾四周，但我被卡住了。

这是我得到的：

SELECT DonorType = CASE WHEN [Criteria1] THEN 'AutoRecurring'
                    WHEN [Criteria2] THEN 'ManualRecurring'
                    ELSE 'NonRecurring' END,
COUNT(DISTINCT AccountNumber) AS TotalDonors, MIN(TotalDonationAmount) AS MinAmount,
MAX(TotalDonationAmount) AS MaxAmount, AVG(TotalDonationAmount) AS AvgAmount,
((SELECT MAX(TotalDonationAmount) 
    FROM (SELECT TOP 50 PERCENT TotalDonationAmount 
        FROM #TempDonors
     ORDER BY TotalDonationAmount) AS BottomHalf)
+ (SELECT MIN(TotalDonationAmount) 
    FROM (SELECT TOP 50 PERCENT TotalDonationAmount 
        FROM #TempDonors
        ORDER BY TotalDonationAmount DESC) AS TopHalf)) / 2 AS MedAmount
FROM #TempDonors
WHERE TotalDonationAmount > 0
GROUP BY CASE WHEN [Criteria1] THEN 'AutoRecurring'
                WHEN [Criteria2] THEN 'ManualRecurring'
                ELSE 'NonRecurring' END

非常感谢您的帮助。如果有另一个帖子问这个问题（我确定有，我只是不知道要搜索什么），请务必发布链接 - 对于我无法找到它，我提前道歉。

保重！

【问题讨论】：

标签： sql-server group-by case median

【解决方案1】：

您需要将中位数计算与外部查询相关联。

看起来像这样：

...
((SELECT MAX(TotalDonationAmount) 
    FROM (SELECT TOP 50 PERCENT TotalDonationAmount 
        FROM #TempDonors t1
        WHERE CASE WHEN t.[Criteria1] THEN 'AutoRecurring'
                WHEN t.[Criteria2] THEN 'ManualRecurring'
                ELSE 'NonRecurring' END=CASE WHEN t1.[Criteria1] THEN 'AutoRecurring'
                WHEN t1.[Criteria2] THEN 'ManualRecurring'
                ELSE 'NonRecurring' END
     ORDER BY TotalDonationAmount) AS BottomHalf)
+ (SELECT MIN(TotalDonationAmount) 
    FROM (SELECT TOP 50 PERCENT TotalDonationAmount 
        FROM #TempDonors t2
        WHERE CASE WHEN t.[Criteria1] THEN 'AutoRecurring'
                WHEN t.[Criteria2] THEN 'ManualRecurring'
                ELSE 'NonRecurring' END=CASE WHEN t2.[Criteria1] THEN 'AutoRecurring'
                WHEN t2.[Criteria2] THEN 'ManualRecurring'
                ELSE 'NonRecurring' END
        ORDER BY TotalDonationAmount DESC) AS TopHalf)) / 2 AS MedAmount
FROM #TempDonors
WHERE TotalDonationAmount > 0
GROUP BY CASE WHEN [Criteria1] THEN 'AutoRecurring'
                WHEN [Criteria2] THEN 'ManualRecurring'
                ELSE 'NonRecurring' END

【讨论】：

我很快就会试一试。谢谢！