主题：求一个SQL语句

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谢谢·！

用狐表我会弄，想学点sql语句··········

Select a.编码,a.列1,b.列2 from a left join (select distinct 编码,列1,列2 from a where 列2 not null or 列2 <> '') as b on a.编码 = b.编码 and a.列1 = b.列1

 select 编码, 列1, (select top 1 列2 from {表A} as b where b.编码 = a.编码 and b.列1 = a.列1 and a.列2 is not null) as 列2 from {表A} as a

3楼、5楼正确、4楼代码【列2】没有显示任何值（估计是a表还没有形成）。

 

我需要的是3楼纯SQL语句的。

 

谢谢三位老师了。。。

 哦，写错鸟，不过还是用连接查询好一点

 

select 编码, 列1, (select top 1 列2 from {表A} as b where b.编码 = a.编码 and b.列1 = a.列1 and b.列2 > '') as 列2 from {表A} as a

select 编码, 列1, (select top 1 列2 from {表A} as b where b.编码 = a.编码 and b.列1 = a.列1 and a.列2 is not null order by 列2 desc) as 列2 from {表A} as a

don老大 真是出神入化

7楼有点甜：ok了·······

8楼的：order by 多余了吧，不是有“列2 is not null” 吗 。

 

再次谢谢