Question

我已设法通过以下方式选择每个重复记录的计数和ID：

select T1.ID,T2.Count
from MyTable T1
join (SELECT ID,Count(*) as Count FROM MyTable 
where Field_C=X 
and Field_S=Y  
group by NumberField,NameField having count(*)>1) T2 
on T1.NumberField=T2.NumberField
and T1.NameField = T2.NameField

这将返回我想要更新的记录的ID（T1.ID）以及我想用（T2.Count）更新CountField的值。

只是不确定如何在到目前为止更改为更新。

Answer 1

如果您已经选择了这样的更新

    UPDATE MyTable T1
    join (SELECT ID,Count(*) as Count FROM MyTable 
    SET T1.ID = T2.Count
    where Field_C=X 
    and Field_S=Y  
    group by NumberField,NameField having count(*)>1) T2 
    on T1.NumberField=T2.NumberField

Answer 2

我想在办公室度过了漫长的一天，但这很容易解决。我认为让第一个选择让我离开，直到我意识到我需要完全摆脱它，因为我没有选择但更新：

Update MyTable T1
join (SELECT ID,Count(*) as Count FROM MyTable 
where Field_C=X 
and Field_S=Y  
group by NumberField,NameField having count(*)>1) T2 
on T1.NumberField=T2.NumberField
and T1.NameField = T2.NameField
Set T1.CountField=T2.Count

将重复的选择转换为更新

2 个答案: