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请原谅我，因为我确定我缺少一些简单的分组查询或子查询，但我可以解决以下问题并需要一些帮助。

我在表中有数据，需要从 PointName 返回不同的值，其中的平均值AdjEasting, AdjNorthing & AdjHeight（这是存在 PointName 值的每一列的前 4 个返回值的平均值）

到目前为止，我有这些数据：

PointName,AdjEasting,AdjNorthing,AdjHeight
51,76672.47700,36190.37870,128.54820
51,76672.47800,36190.38060,128.55070
51,76672.47680,36190.38010,128.55020
51,76672.47640,36190.37910,128.55020
51,76672.47690,36190.37930,128.54990
51,76672.47740,36190.38050,128.54990
52,76781.27600,36069.18870,127.80420
52,76781.27580,36069.18800,127.80350
52,76781.27580,36069.18930,127.80310
52,76781.27630,36069.18900,127.80370
52,76781.27630,36069.18870,127.80330
53,76905.20930,35932.21400,126.79920
53,76905.20910,35932.21290,126.79970
53,76905.20550,35932.21180,126.79950
53,76905.20820,35932.21350,126.80080
53,76905.20910,35932.21380,126.79920
53,76905.20830,35932.21370,126.80160
55,77050.28410,36001.64670,128.73920
55,77050.28400,36001.64790,128.73990
55,77050.28440,36001.64590,128.74010
55,77050.28400,36001.64650,128.74010
55,77050.28360,36001.64590,128.74010
55,77050.28500,36001.64780,128.73990
55,77050.28630,36001.64760,128.74200,
55,77050.28430,36001.64630,128.73960

...我想要这些数据：

51,76672.47705,36190.37963,128.54983
52,76781.27598,36069.18875,127.80363
53,76905.20803,35932.21305,126.79980
55,77050.28413,36001.64675,128.73983

这是我的查询，但它返回一个不同的 ID，但 ID 中的每条记录的平均值相同：

SELECT DISTINCT
    PointName
    ,(SELECT avg(AvEasting)
      FROM
         (SELECT TOP 4
              cast(AdjEasting as float) as AvEasting
          FROM AdjFile
          ORDER BY PointName, epoch desc) AdjFile)
    ,(SELECT avg(AvNorthing)
      FROM
          (SELECT TOP 4
               cast(AdjNorthing as float) as AvNorthing
           FROM AdjFile
           ORDER BY PointName, epoch desc) AdjFile)
    ,(SELECT avg(AvHeight)
      FROM 
          (SELECT TOP 4
              cast(AdjHeight as float) as AvHeight
           FROM AdjFile
           ORDER BY PointName,epoch desc) AdjFile)
FROM AdjFile</P>



编辑

我可以使用以下代码获取要返回的单个值：

SELECT PointName ,avg(AvEasting) ,avg(AvNorthing) ,avg(AvHeight) FROM
(SELECT TOP 4 PointName ,cast(AdjEasting as float) as AvEasting ,cast(AdjNorthing as float) as AvNorthing ,cast(AdjHeight as float) as AvHeight FROM AdjFile ORDER BY PointName,epoch desc) AdjFile GROUP BY PointName ORDER BY PointName

4

1 回答 1

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从你的方法开始，这样的事情怎么样：

SELECT af.PointName,
(SELECT AVG(Top4AdjEasting) AS AvEasting FROM
(SELECT TOP 4
 CAST(af2.AdjEasting AS FLOAT) AS Top4AdjEasting
 FROM AdjFile af2
 WHERE af2.PointName = af.PointName
 ORDER BY Top4AdjEasting desc)),
(SELECT AVG(Top4AdjNorthing) AS AvNorthing FROM
(SELECT TOP 4
 CAST(af3.AdjNorthing AS FLOAT) AS Top4AdjNorthing
 FROM AdjFile af3
 WHERE af3.PointName = af.PointName
 ORDER BY Top4AdjNorthing desc)),
(SELECT AVG(Top4AdjHeight) AS AvHeight FROM
(SELECT TOP 4
 CAST(af4.AdjHeight AS FLOAT) AS Top4AdjHeight
 FROM AdjFile af4
 WHERE af4.PointName = af.PointName
 ORDER BY Top4AdjHeight desc))
FROM AdjFile af
GROUP BY af.PointName
ORDER BY af.PointName

那对你有用吗？

于 2013-05-07T16:45:53.627 回答