sql server语言 - Pivot or unpivot

Question

我有一个每小时的统计数据表，我需要pivot(或unpivot?)

起始表的格式为:

[SystemID] [Hour] [CallStarts] [AvgDuration]  
    1         0        3           27
    1         1       10           58
    1         2       43           45
    1         3       54           63
    2         0        6           56
    2         1       46           98
    2         2       56           67
    2         3       65           77  

我需要的输出是:

[SystemID] [Statistic] [Hr0] [Hr1] [Hr2] [Hr3]  
     1     CallStarts    3    10     43    54  
     1     AvgDuration  27    58     45    63
     2     CallStarts    6    46     56    65
     2     AvgDuration  56    98     67    77  

我正在使用SQL Server 2008R2。我了解数据透视表的基本知识，但我没有太多的经验。是[统计]专栏让我吃亏。

Answer 1

这里有一种不需要枢轴的方法，根据索引和数据大小，它可能更快:

SELECT SystemID, 
       MAX('CallStarts') AS Statistic, 
       SUM(CASE WHEN Hour = 0 THEN CallStarts ELSE 0 END) AS Hr0,
       SUM(CASE WHEN Hour = 1 THEN CallStarts ELSE 0 END) AS Hr1,
       SUM(CASE WHEN Hour = 2 THEN CallStarts ELSE 0 END) AS Hr2,
       SUM(CASE WHEN Hour = 3 THEN CallStarts ELSE 0 END) AS Hr3
FROM Table
GROUP BY SystemID
  UNION ALL
SELECT SystemID, 
       MAX('AvgDuration') AS Statistic, 
       SUM(CASE WHEN Hour = 0 THEN AvgDuration ELSE 0 END) AS Hr0,
       SUM(CASE WHEN Hour = 1 THEN AvgDuration ELSE 0 END) AS Hr1,
       SUM(CASE WHEN Hour = 2 THEN AvgDuration ELSE 0 END) AS Hr2,
       SUM(CASE WHEN Hour = 3 THEN AvgDuration ELSE 0 END) AS Hr3
FROM Table
GROUP BY SystemID
ORDER BY SystemID, Statistic ASC

Answer 2

您可以单独查询每种类型的统计信息，然后将它们合并。我在SQL Fiddle上使用了@attila构建的相同模式。

WITH callS AS (SELECT systemid, hour, callstarts FROM t),
callD AS (SELECT systemid, hour, avgduration FROM t)
SELECT systemid, 'callStarts' AS [statistics], [0] as Hr0, [1] as Hr1, [2] as Hr2, [3] AS Hr3
FROM callS pivot (max(callStarts) FOR hour IN ([0], [1], [2], [3])) AS p
UNION ALL
SELECT systemid, 'AvgDuration' AS [statistics], [0], [1], [2], [3]
FROM callD pivot (max(avgduration) FOR hour IN ([0], [1], [2], [3])) AS p2
ORDER BY systemid, [statistics] DESC;

输出如下所示:http://www.sqlfiddle.com/#!3/eb109/20/0

Answer 3

你的想法是对的…旋转，然后旋转。也许有更好的方法，但这是可行的:

SELECT *
FROM (
    SELECT SystemId, [Hour], [Stat], [Statistics]
    FROM
        (SELECT systemid, [hour], CallStarts, AvgDuration FROM t) nt
    UNPIVOT
        (stat FOR [Statistics] IN (CallStarts, AvgDuration)) AS ut
    ) AS ap
PIVOT
    (SUM (Stat) FOR [Hour] IN ([0], [1], [2], [3], [4])) AS p
ORDER BY [SystemId], [Statistics] DESC

下面是一个sqlfiddle显示它工作:http://www.sqlfiddle.com/#!3/eb109/8/0