SQL Server将行转换为列

Question

我正在使用TSQL存储过程，我需要将临时表列转换为行。目前我正在逐一使用更新表，但我认为使用pivot和unpivot可以轻松实现。

数据源：

Periods  Stat1  Stat2  Stat3  Stat4 
-------------------------------------------------------- 
Value1  1.011  1.012  1.013  1.014 
Value2  1.011  1.021  1.031  1.041 
Value3  1.011  2.211  1.311  1.411 

期望输出：

Stats  Value1  Value2  Value3 
----------------------------------------------- 
Stat1   1.011  1.011  1.011  
Stat2   1.012  1.021  1.211 
Stat3   1.013  1.031  1.311 
Stat4   1.014  1.041  1.411 

真的很感激任何帮助？

Answer 1

正如你指出这是unpivoting然后旋转数据的过程：

with statTable as 
(
select periods = 'Value1', Stat1 = 1.011, Stat2 = 1.012, Stat3 = 1.013, Stat4 = 1.014 
union all select 'Value2', 1.011, 1.021, 1.031, 1.041 
union all select 'Value3', 1.011, 2.211, 1.311, 1.411 
) 
, up as 
(
    select periods, 
    c.[Stats], 
    c.value 
    from statTable 
    cross apply 
    (
    values ('Stat1', Stat1), ('Stat2', Stat2), ('Stat3', Stat3), ('Stat4', Stat4) 
) c ([Stats], value) 
) 
select [Stats], 
    Value1, 
    Value2, 
    Value3 
from up 
pivot 
(
    sum(value) 
    for periods in (Value1, Value2, Value3) 
) p 

SQL Fiddle with demo。

如果你不使用SQL Server 2008或以上，你可以使用UNPIVOT而不是CROSS APPLY：

with statTable as 
(
select periods = 'Value1', Stat1 = 1.011, Stat2 = 1.012, Stat3 = 1.013, Stat4 = 1.014 
union all select 'Value2', 1.011, 1.021, 1.031, 1.041 
union all select 'Value3', 1.011, 2.211, 1.311, 1.411 
) 
, up as 
(
    select periods, 
    up.[Stats], 
    up.value 
    from statTable 
    unpivot 
    (
    value 
    for [Stats] in (Stat1, Stat2, Stat3, Stat4) 
) up 
) 
select [Stats], 
    Value1, 
    Value2, 
    Value3 
from up 
pivot 
(
    sum(value) 
    for periods in (Value1, Value2, Value3) 
) p 

SQL Fiddle with demo。