Sql 将列旋转为行，同时将行旋转为列。（SSMS）

我有下表…我们称之为表1

 TERM           PERIOD  Average     StandardDeviation   Minimum
+ 1 Period      2012Q3  0.00417     0.00722             0
+ 120 Periods   2012Q3  0.02951     0.0014              0.028615
+ 20 Periods    2012Q3  0.009898    0.0037              0.007612
+ 40 Periods    2012Q3  0.018255    0.00262             0.016565
+ 1 Period      2012Q4  0.005       0.007               0
+ 120 Periods   2012Q4  0.026       0.001               0.03
+ 20 Periods    2012Q4  0.007       0.003               0.0042
+ 40 Periods    2012Q4  0.018       0.002               0.0165

有没有一种方法可以对其进行编码，这样我就可以得到一个如下所示的表：

TERM           PATHS              2012Q3    2012Q4
+ 1 Period     Average            0.00417   0.005
+ 1 Period     StandardDeviation  0.00722   0.007
+ 1 Period     Minimum            0         0

---

…依此类推，每项（+120个周期，+40个周期等）。

要生成此结果，您需要同时使用和函数。

UNPIVOT

将列

平均值

、

标准偏差

和

最小值

转换为多行。有了这些行后，就可以将

透视

应用于

期间

值。您的代码与此类似：

select term, paths,[2012Q3], [2012Q4]
from
(
  select term, period, paths, value
  from
  (
    select term, period, Average, StandardDeviation, Minimum
    from table1
  ) s
  unpivot
  (
    value
    for paths in (Average, StandardDeviation, Minimum)
  ) unpiv
) src
pivot
(
  max(value)
  for period in ([2012Q3], [2012Q4])
) piv

看

这也可以通过使用

UNION ALL

来取消pivot数据，使用带有

CASE

表达式的聚合函数来透视：

select term,
  paths,
  max(case when period = '2012Q3' then value end) [2012Q3],
  max(case when period = '2012Q4' then value end) [2012Q4]
from
(
  select term, period, 'Average' Paths, average value
  from Table1
  union all
  select term, period, 'StandardDeviation' Paths, StandardDeviation
  from Table1
  union all
  select term, period, 'Minimum' Paths, Minimum
  from Table1
) src
group by term,  paths

看

如果您有已知数量的

period

值，则上述版本非常有效。如果没有，则需要使用动态sql生成结果：

DECLARE @cols AS NVARCHAR(MAX),
    @query  AS NVARCHAR(MAX)

select @cols = STUFF((SELECT DISTINCT ',' + QUOTENAME(PERIOD) 
                    from Table1
            FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)') 
        ,1,1,'')

set @query 
    = 'select term, paths, '+@cols+'
       from
       (
         select term, period, paths, value
         from
         (
           select term, period, Average, StandardDeviation, Minimum
           from table1
         ) s
         unpivot
         (
           value
           for paths in (Average, StandardDeviation, Minimum)
         ) unpiv
       ) p
       pivot
       (
          max(value)
          for period in('+@cols+')
       ) piv'

execute(@query)

看

---

所有版本都会产生相同的结果。

要产生此结果，您需要同时使用和函数。

UNPIVOT

将列

平均值

、

标准偏差

和

最小值

转换为多行。有了这些行后，就可以将

透视

应用于

期间

值。您的代码与此类似：

select term, paths,[2012Q3], [2012Q4]
from
(
  select term, period, paths, value
  from
  (
    select term, period, Average, StandardDeviation, Minimum
    from table1
  ) s
  unpivot
  (
    value
    for paths in (Average, StandardDeviation, Minimum)
  ) unpiv
) src
pivot
(
  max(value)
  for period in ([2012Q3], [2012Q4])
) piv

看

这也可以通过使用

UNION ALL

来取消pivot数据，使用带有

CASE

表达式的聚合函数来透视：

select term,
  paths,
  max(case when period = '2012Q3' then value end) [2012Q3],
  max(case when period = '2012Q4' then value end) [2012Q4]
from
(
  select term, period, 'Average' Paths, average value
  from Table1
  union all
  select term, period, 'StandardDeviation' Paths, StandardDeviation
  from Table1
  union all
  select term, period, 'Minimum' Paths, Minimum
  from Table1
) src
group by term,  paths

看

如果您有已知数量的

period

值，则上述版本非常有效。如果没有，则需要使用动态sql生成结果：

DECLARE @cols AS NVARCHAR(MAX),
    @query  AS NVARCHAR(MAX)

select @cols = STUFF((SELECT DISTINCT ',' + QUOTENAME(PERIOD) 
                    from Table1
            FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)') 
        ,1,1,'')

set @query 
    = 'select term, paths, '+@cols+'
       from
       (
         select term, period, paths, value
         from
         (
           select term, period, Average, StandardDeviation, Minimum
           from table1
         ) s
         unpivot
         (
           value
           for paths in (Average, StandardDeviation, Minimum)
         ) unpiv
       ) p
       pivot
       (
          max(value)
          for period in('+@cols+')
       ) piv'

execute(@query)

看

---

所有版本都会产生相同的结果。

我将其视为聚合和连接

select term, paths,
       MIN(case when period = '2012Q3'
                then (case when which = 'Average' then t.average
                           when which = 'StandardDeviation' then t.StandardDeviation
                           when which = 'Minimum' then t.Minimum
                      end)
            end) as "2012Q3",
       MIN(case when period = '2012Q4' 
                then (case when which = 'Average' then t.average
                           when which = 'StandardDeviation' then t.StandardDeviation
                           when which = 'Minimum' then t.Minimum
                      end)
            end) as "2012Q4"
from Table1 t cross join
     (select 'Average' as paths union all
      select 'StandardDeviation' union all
      select 'Minimum'
     ) const
group by term, paths

---

我将其视为聚合和连接

select term, paths,
       MIN(case when period = '2012Q3'
                then (case when which = 'Average' then t.average
                           when which = 'StandardDeviation' then t.StandardDeviation
                           when which = 'Minimum' then t.Minimum
                      end)
            end) as "2012Q3",
       MIN(case when period = '2012Q4' 
                then (case when which = 'Average' then t.average
                           when which = 'StandardDeviation' then t.StandardDeviation
                           when which = 'Minimum' then t.Minimum
                      end)
            end) as "2012Q4"
from Table1 t cross join
     (select 'Average' as paths union all
      select 'StandardDeviation' union all
      select 'Minimum'
     ) const
group by term, paths

---

谢谢很好用。@Kristina不客气，很乐意帮忙。：）是的，当我有一大堆专栏文章时，我总是尝试使用动态SQL！很好用。@Kristina不客气，很乐意帮忙。：）是的，当我有一大堆列时，我总是尝试使用动态SQL