Question

从TableName中选择*

从此：

ID     Col1    Col2    Col3   Col4    Col5
1       aa      21      ss     m        p
2       aa      21      tt     f        u
3       bb      21      ss     f        d
4       bb      22      ss     m        d

到这个

ID     Col1    Col2    Col3   Col4    Col5
1       aa      21      ss     m        p
2                       tt     f        u
3       bb              ss              d
4               22             m

我希望这个输出有可能吗？

如果它位于相同的

旁边，则不要重复重复值

感谢您的时间。

Answer 1

请检查查询，这是您需要的吗？：

update a set 
    a.Col1=(case when cnt1=1 then a.Col1 else null end),
    a.Col2=(case when cnt2=1 then a.Col2 else null end),
    a.Col3=(case when cnt3=1 then a.Col3 else null end)
from TableName a
join
(
    select *, 
        row_number() over (Partition By Col1 order by ID) cnt1,
        row_number() over (Partition By Col2 order by ID) cnt2,
        row_number() over (Partition By Col3 order by ID) cnt3
    From TableName
) x on a.ID=x.ID

Answer 2

您可以选择要临时表的所有内容，清除重复的值并从更新的临时表中返回结果集。

查询可能如下所示：

select 1 as id, 'aa' as col1, '21' as col2,'ss' as col3,'m' as col4,'p' as col5 into #tmp union
select 2, 'aa','21','tt','f','u' union
select 3, 'bb','21','ss','f','d' union
select 4, 'bb','22','ss','m','d' 


update t set
    col1 = case when tp.col1 = t.col1 then '' else t.col1 end,
    col2 = case when tp.col2 = t.col2 then '' else t.col2 end,
    col3 = case when tp.col3 = t.col3 then '' else t.col3 end,
    col4 = case when tp.col4 = t.col4 then '' else t.col4 end,
    col5 = case when tp.col5 = t.col5 then '' else t.col5 end
from #tmp t
left join (
    select t1.id, max(t2.id) as pid
    from #tmp t1
    join #tmp t2 on t1.id > t2.id
    group by t1.id
) p on t.id = p.id
left join #tmp tp on p.pid = tp.id

结果：

/*------------------------
select top 100 * from  #tmp
------------------------*/
id   col1    col2    col3    col4    col5
1    aa      21      ss      m       p
2                    tt      f       u
3    bb              ss              d
4            22              m

SQL Fiddle

如何从表中删除重复的列值

2 个答案: