Question

我有一个包含以下架构的表：

DateTime [Creation Date] PK
int [Data]

列数据具有来自传感器的值，如下所示：

正如您所看到的，值总是递增。

由于传感器存在问题，我们有时会在有效值之间获得0。当我们尝试使用数据时，这会产生一些问题，因此我们希望用某些东西来填补这些空白。理想情况下，我们希望在上一个值和下一个值之间加上平均值，如果不可能，我们想重复之前的值。

这只是一个问题吗？

提前致谢。

Answer 1

也许不是最有效的，但应该有效：

WITH cte 
     AS (SELECT [Creation Date], 
                Data, 
                rn=Row_number() OVER(ORDER BY [Creation Date]) 
         FROM   dbo.Table) 
UPDATE cte 
SET    Data = ( ( (SELECT c2.Data
                    FROM   cte c2 
                    WHERE  c2.rn = cte.rn - 1) 
                   + (SELECT c2.Data
                      FROM   cte c2 
                      WHERE  c2.rn = cte.rn + 1) ) / 2 ) 
WHERE  Data = 0;

我在CTE中使用Row_Number来获取Creation Date排序的连续数字。然后，此数字用于根据其上一个和下一个值获取新数据。

Here's具有类似架构的演示（我使用int代替datetime）：

更新

很好，但它没有处理多个0的差距

好的捕获，这是修改后的sql，它考虑到了这一点：

WITH cte 
     AS (SELECT [Creation Date], 
                Data, 
                rn=Row_number() OVER(ORDER BY [Creation Date]) 
         FROM   dbo.Table) 
UPDATE cte 
SET    Data = ( ( (SELECT c2.Data
                    FROM   cte c2 
                    WHERE  c2.rn = (SELECT MAX(RN)FROM CTE c3 WHERE c3.RN<cte.RN AND c3.Data<>0)) 
                   + (SELECT c2.Data
                      FROM   cte c2 
                      WHERE  c2.rn = (SELECT MIN(RN)FROM CTE c3 WHERE c3.RN>cte.RN AND c3.Data<>0))) / 2 ) 
WHERE  Data = 0;

Demo（在5,6上连续为零）

Answer 2

我有另一种变化：

SELECT 
BadDate, 
T1.Data AS PrevData, 
T2.Data AS NextData,
(T1.Data + T2.Data) / 2 AS AvgValue
FROM

(

SELECT 
T1.CreationDate As BadDate, 
Max(T2.CreationDate) As PrevDate,
Min(T3.CreationDate) As NextDate

FROM 
TestData T1, 
TestData T2,
TestData T3

WHERE 

T1.Data = 0
AND T2.Data <> 0
AND T2.CreationDate < T1.CreationDate
AND T3.Data <> 0
AND T3.CreationDate > T1.CreationDate

GROUP BY T1.CreationDate

) DateData

INNER JOIN TestData T1
ON DateData.PrevDate = T1.CreationDate

INNER JOIN TestData T2
ON DateData.NextDate = T2.CreationDate

Answer 3

如果您不担心获得平均值，此方法可以为之前的值添加数字。

另请注意，我不确定此方法是否有任何问题（除了更新所有记录），但仅仅显示为一种不同且简单的方法......

declare @new int = 1

update mytable
set @new  = val  = case when val = 0 then @new + 1 else val end

Fiddle demo

|          D |  VAL |
---------------------
| 2013-01-01 |  123 |
| 2013-01-02 |  225 |
| 2013-01-03 |  354 |
| 2013-01-04 |  578 |
| 2013-01-05 |  579 |--Updated
| 2013-01-06 | 2151 |
| 2013-01-07 | 2331 |
| 2013-01-08 | 2332 |--Updated
| 2013-01-09 | 2555 |
| 2013-01-10 | 2678 |

Answer 4

还有一个选择

UPDATE s
SET s.Data = (COALESCE(o1.Data, o2.Data) + COALESCE(o2.Data, o1.Data)) / 2
FROM dbo.sensor s OUTER APPLY (
                               SELECT TOP 1 s2.Data AS Data
                               FROM dbo.sensor s2
                               WHERE s2.Data != 0 AND s.[Creation Date] < s2.[Creation Date]
                               ORDER BY s2.[Creation Date] ASC                         
                               ) o1
                  OUTER APPLY (
                               SELECT TOP 1 s3.Data AS Data
                               FROM dbo.sensor s3
                               WHERE s3.Data != 0 AND s.[Creation Date] > s3.[Creation Date]                               
                               ORDER BY s3.[Creation Date] DESC 
                               ) o2
WHERE s.Data = 0

SQLFiddle上的演示

由于数据错误，创建一个查询以填补表中的空白

4 个答案: