Sql 如何计算嵌套查询中每年的平均值？

我想计算一年的平均值，情况如下

 Plant_ID | Year | Month  |  MR   | Range  
  CCAR    | 2009 | 1      | 0,706 | Null  
  CCAR    | 2009 | 2      | 0,626 | 0,08  
  CCAR    | 2009 | 3      | 0,637 | 0,11  
  CCAR    | 2009 | 4      | 0,737 | 0,1  
  CCAR    | 2009 | 5      | 0,552 | 0,19  
  CCAR    | 2009 | 6      | 0,418 | 0,137  
  CCAR    | 2009 | 7      | 0,503 | 0,085  
  CCAR    | 2009 | 8      | 0,645 | 0,058  
  CCAR    | 2009 | 9      | 0,743 | 0,098  
  CCAR    | 2009 | 10     | 0,556 | 0,187  
  CCAR    | 2009 | 11     | 0,298 | 0,258  
  CCAR    | 2009 | 12     | 0,339 | 0,041  
  CCAR    | 2010 | 1      | 0,381 | 0,042  
  Etc.  

我想增加两栏；1aMR用于计算每年的平均MR维护率，因此一个用于2009年、一个用于2010年等，第二个用于计算每年的平均范围。我的问题是，我不知道在我的查询中该在哪里做，因为它变得有点复杂，我无法处理。。。。我已经声明添加了ColumAMR，这是MR的平均值，请参见下面的查询代码。但是我不能得到每年的平均值，现在它返回所有MR值的总平均值，有人能帮我吗

WITH cte AS (
SELECT Plant_Id, 
       Jaar, 
       Maand, 
      (SUM(Compl) + 0.000) / SUM(Total) AS MR,
       ROW_NUMBER() OVER (ORDER BY Jaar DESC, 
       Maand DESC) AS RowNumber  
FROM (SELECT Plant_Id, 
             Jaar, 
             Late, 
             EarlyJobs, 
             OnTimeJobs, 
             Maand, SUM(EarlyJobs +OnTimeJobs) AS Compl, 
             SUM(EarlyJobs) + SUM(Late) + SUM(OnTimeJobs) AS Total  
      FROM MaintenanceRatebepaen AS MaintenanceRatebepaen_1  
      GROUP BY Plant_Id, Jaar, Maand, Late, OnTimeJobs, EarlyJobs) AS MaintenanceRatebepaen  
WHERE (Jaar >= 2009) AND (Jaar <= 2011) AND (Plant_Id = 'CCAR')  
GROUP BY Jaar, Plant_Id, Maand) 

SELECT d1.Plant_Id, 
       d1.Jaar, 
       d1.Maand, 
       d1.MR, 
       abs(d1.MR - d2.MR) AS [ChangeMRFromPreviousMonth], 
       aMR =(SELECT avg(cte.MR) FROM cte)  
FROM cte d1 
LEFT OUTER JOIN cte d2 ON d2.RowNumber = (d1.RowNumber + 1)  
ORDER BY d1.Rownumber DESC  

所以我想增加两个栏目；一个用于计算MR aMR每年的平均值，另一个用于计算每年平均范围的列。有人能帮我吗？我对SQL非常陌生，任何帮助都将不胜感激

尝试用替换aMR=从cte中选择avgcte.MR

我不确定d1.Maand。如果它表示月份，请按从分区中删除它。至于范围或更改？，您也可以尝试：

aChange = avg (d1.MR - d2.MR) over (partition by d1.Plant_Id, d1.Jaar, d1.Maand)

然后，您可以加入此计算方差或类似值

SELECT 
    t.*
    ,c.*
    ,t.mr - c.avgMR as MRvariance
    ,t.Range - c.avgRange as RangeVariance
 FROM
    table as t
        INNER JOIN (
            SELECT 
                PLant_id
                ,year
                ,avg(mr) as avgMR
                ,avg(range) as avgRange
            FROM 
                table
            GROUP BY
                Plant_id,year
      ) as c
          ON c.plant_id = t.plant_id
          AND c.year = t.year

---

如果您可以访问myTable Plant_ID、年、月、MR、范围等表格，您已经完成了大部分工作：

SELECT year, AVG(MR) AS "avg_mr", AVG(range) AS "avr_range"
FROM myTable
GROUP BY year;

如果此数据是复杂查询的结果，只需替换此查询的假设表名：

SELECT year, AVG(MR) AS "avg_mr", AVG(range) AS "avr_range"
FROM (
    SELECT ... FROM ... -- complex query goes here
)
GROUP BY year;

---

明亮的很有效，非常感谢！我已经试了好几天了。

SELECT year, AVG(MR) AS "avg_mr", AVG(range) AS "avr_range"
FROM myTable
GROUP BY year;

SELECT year, AVG(MR) AS "avg_mr", AVG(range) AS "avr_range"
FROM (
    SELECT ... FROM ... -- complex query goes here
)
GROUP BY year;