Question

有五个专栏。如何获取行（而不是列）的平均值，以及计算平均值时应排除最大值和最小值。

如果存在重复的最大值或（和）最小值，如何将它们全部排除？

我的数据结果应该是这样的。

    Path topDir = Paths.get(RECURSIVE_DIRECTORY);
    Files.walk(topDir)
        .filter(path -> path.getFileName().toString().endsWith(".7z"))
        .forEach(path -> {
            try {
                JThreadTar.decompressSevenz(path.toString(), topDir.toFile());
            } catch (IOException e2) {
                e2.printStackTrace();
            }
    });

我的数据集如下；

Average_MIN_MAX_excluded
-------------------------
3.33333333
5.33333333

Answer 1

select ((c1 + c2 + c3 + c4 + c5) -
          greatest( c1, c2, c3, c4, c5 ) -
          least( c1, c2, c3, c4, c5 ))/ 3
  from DATAA

将是一种方式。这是liveSQL link

Answer 2

这是使用LATERAL JOIN或CROSS APPLY的好地方：

SELECT *
FROM t
CROSS APPLY (
 SELECT AVG(c) AS Average_MIN_MAX_excluded
 FROM (
  SELECT c, ROW_NUMBER() OVER(ORDER BY c) rn
  FROM (
    SELECT c1 c FROM dual UNION ALL
    SELECT c2 FROM dual UNION ALL
    SELECT c3 FROM dual UNION ALL
    SELECT c4 FROM dual UNION ALL
    SELECT c5 FROM dual) 
 )
 WHERE rn NOT IN (1,5)
) s;

如果需要，此方法可以轻松排除1,2,3个最高/最低值。

db<>fiddle demo

Answer 3

我认为您可以将unpivot和analytical function的聚合函数与group by和average结合使用，如下所示：

WITH DATAA AS
(
SELECT 3 c1,5 c2,4 c3,3 c4 ,1 c5 FROM DUAL
UNION
-- case with same value at min for two columns
SELECT 1 c1,5 c2,4 c3,3 c4 ,1 c5 FROM DUAL
UNION
SELECT  1 c1,3 c2,6 c3,9 c4 ,7 c5 FROM DUAL)

-- your query starts from here
select rn, avg(val) from
(select rn, val, 
      max(val) over (partition by rn) maxval,
      min(val) over (partition by rn) minval
from
(SELECT rownum rn, c1, c2, c3, c4, c5
FROM DATAA)
unpivot
(val for vals in (c1,c2,c3,c4,c5)))
where val not in (maxval, minval)
group by rn

请参见db<>fiddle演示。

干杯！

如何获得Oracle中排除了最小值和最大值的行的平均值？

3 个答案: