sql - 将列值转换为列名 SQL Server

Question

我有一个具有以下架构的表。希望在 SQL Server 中获得预期结果。由于值列是字符串，因此数据透视表不起作用。请建议实现这一目标的有效方法。谢谢!

表:

 Dim Key(String) , Dim Value (String)
   AB                XY1 
   AB                XY2
   CD                XY3
   CD                XY4

预期结果

New columns=>  AB      CD
Row values =>  XY1     XY3
               XY2     XY4

Answer 1

您想要row_number():

select max(case when key = 'ab' then Value end) as ab, 
       max(case when key = 'cd' then Value end) as cd
from (select t.*, 
             row_number() over (partition by key order by Value) as seq
      from table t
     ) t
group by seq;

但是，您的 pivot 版本也应该适用于 row_number()。

编辑:

select tt.*
from (select t.*, 
             row_number() over (partition by [key] order by Value) as seq
      from table t
     ) as t pivot 
     ( max(value) for [key] in ([ab], [cd]) 
     ) tt;