MS 访问用最近的非零行替换空值或零值

Question

我有一个这样的示例数据集

 Group  Age Value
    A   1   
    A   2   0
    A   3   20
    B   1   0
    B   2   0
    B   3   25
    B   4   0
    B   5   0
    B   6   50

对于 Group 中的每个不同值，替换空值或零 Value。理想的输出将是

 Group  Age Value
    A   1   20
    A   2   20
    A   3   20
    B   1   25
    B   2   25
    B   3   25
    B   4   25
    B   5   50
    B   6   50

更新

这似乎可以解决问题

UPDATE test
SET [Value] = nz(DMin(
    "[Value]", 
    "test", 
    "[Group] = '" & [Group] & "' AND 
     [Age] < " & [Age] & " AND 
     [Value] <> 0 AND [Value] IS NOT NULL"
),
 DMax(
    "[Value]", 
    "test", 
    "[Group] = '" & [Group] & "' AND 
     [Age] > " & [Age] & " AND 
     [Value] <> 0 AND [Value] IS NOT NULL"
))
WHERE [Value] = 0 OR [Value] IS NULL;

Answer 1

您可以使用它（在 MsAccess SQL 中，可以从返回一个值或没有行的子查询派生一列）：


select 
     tactl.[Group], 
     tactl.Age, 
     (  select trepl.[Value]
        from test trepl
        where tactl.[Group]=trepl.[Group]
              and nz(trepl.[Value],0)<>0
              and abs(tactl.Age-trepl.Age)=
                      ( select MIN(abs(ta.Age-tb.Age)) as MinDistanceFound 
                        from    test ta
                                inner join
                                test tb
                                on (ta.[Group]=tb.[Group]  and nz(tb.[Value],0) <> 0)
                       where (ta.[Group]=tactl.[Group]  and ta.[Age]=tactl.[Age])
                    )
      )  as [Value]
from test tactl

GROUP 和 VALUE 在大多数 SQL 实现中可以是保留字（它们在 Access 中）；尝试用其他词来代替它们（我把它们放在括号中以克服问题）

Answer 2

考虑 DMin 等域聚合以获得可更新的查询：

UPDATE test
SET [Value] = DMin(
    "[Value]", 
    "test", 
    "[Group] = '" & [Group] & "' AND 
     [Age] > " & [Age] & " AND 
     [Value] <> 0 AND [Value] IS NOT NULL"
)
WHERE [Value] = 0 OR [Value] IS NULL;

MS 访问用最近的非零行替换空值或零值

MS access replace null or zero values with nearest non-zero row

sql

ms-access