Question

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.

我想添加两列; 1（aMR）计算每年的平均MR（维持率），因此计算2009年的平均值，2010年的平均值等，以及计算每年平均范围的第二个平均值。我的问题是我不知道在我的查询中这是做什么的，因为它有点复杂然后我可以处理....我已经做了一个声明添加一个colum aMR，这是MR的平均值（见查询代码如下）。但我每年都无法得到一个平均值（现在它返回所有MR值的总平均值）有人可以帮我这个吗？

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

所以我想要添加两列;一个计算每年MR（aMR）的平均值，另一个计算每年平均范围的列。有人可以帮我这个吗？我对SQL很陌生，任何帮助都将不胜感激！

Answer 1

如果你可以到myTable (Plant_ID, Year, Month, MR, Range)这样的桌子，你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;

如果此数据来自复杂查询，则只需替换查询的此假设表名称：

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

Answer 2

尝试用

替换aMR =(SELECT avg(cte.MR) FROM cte)

aMR = avg (d1.MR) over (partition by d1.Plant_Id, d1.Jaar, d1.Maand)

我对d1.Maand不确定。如果它表示月份，则将其从分区中删除。对于Range（或Change？），您也可以尝试：

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

Answer 3

SELECT 
    PLant_id
    ,year
    ,avg(mr) as avgMR
    ,avg(range) as avgRange
 FROM 
    table
 GROUP BY
  Plant_id,year

然后您可以加入此计算方差或类似

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

如何计算嵌套查询中的每年平均值？

3 个答案: