Question

我有一个SQL Server的结果集，如下所示：

Zone        M1      M2  M3  M4  M5  M6  M7
NORTH       6233    17743   2   6233    6717    7369    7369
SOUTH       12440   20017   7   8057    9724    13418   13418
WEST        33736   30532   5   2184    2056    1944    1944
EAST        3944    14584   2   728     953     970     970
CENTRAL     6233    3636    2   6233    6717    6825    6825

但我希望以下列方式：

M       NORTH   SOUTH   WEST    EAST    CENTRAL
M1      6233    12440   33736   3944    6233
M2      17743   20017   30532   14584   3636
M3      2       7       5       2       2
M4      ....

怎么做？

否则，我怎么能以这种格式得到它：

Zone    M   Value
EAST    M1  6322
WEST    M1  27387
EAST    M2  2345
....

Answer 1

获得结果需要做的是实现UNPIVOT和PIVOT函数的两步过程。

第一步是UNPIVOT数据，这需要您的多个列M1，M2等，并将它们分为两列，其中包含值和列名称：

select zone, value, col
from data
unpivot
(
  value
  for col in ([M1], [M2], [M3], 
              [M4], [M5], [M6], [M7])
) unpiv;

请参阅SQL Fiddle with Demo

执行UNPIVOT后，您可以将PIVOT应用于Zone列：

select *
from
(
  select zone, value, col
  from data
  unpivot
  (
    value
    for col in ([M1], [M2], [M3], 
                [M4], [M5], [M6], [M7])
  ) unpiv
) src
pivot
(
  sum(value)
  for zone in ([North], [South], [West], [East], [Central])
) piv;

请参阅SQL Fiddle with Demo

现在，如果您无法访问PIVOT和UNPIVOT功能，那么您可以使用UNION ALL UNPIVOT执行相同的操作，并使用CASE复制PIVOT：

select col,
  sum(case when zone='North' then value end) North,
  sum(case when zone='South' then value end) South,
  sum(case when zone='West' then value end) West,
  sum(case when zone='East' then value end) East,
  sum(case when zone='Central' then value end) Central
from
(
  select zone, M1 value, 'M1' col
  from data
  union all
  select zone, M2 value, 'M2' col
  from data
  union all
  select zone, M3 value, 'M3' col
  from data
  union all
  select zone, M4 value, 'M4' col
  from data
  union all
  select zone, M5 value, 'M5' col
  from data
  union all
  select zone, M6 value, 'M6' col
  from data
  union all
  select zone, M7 value, 'M7' col
  from data
) un
group by col

请参阅SQL Fiddle with demo

最后，如果你有一个未知数量的列要进行unpivot或pivot，那么你可以使用它的动态版本：

DECLARE @colsUnpivot AS NVARCHAR(MAX),
    @query  AS NVARCHAR(MAX),
    @colsPivot as  NVARCHAR(MAX)

select @colsUnpivot = stuff((select ','+quotename(C.name)
         from sys.columns as C
         where C.object_id = object_id('data') and
               C.name not in ('zone')
         for xml path('')), 1, 1, '')

select @colsPivot = STUFF((SELECT  distinct ',' 
                      + quotename(Zone)
                    from data
            FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)') 
        ,1,1,'')


set @query 
  = 'select *
     from
     (
        select zone, value, col
        from data
        unpivot
        (
          value
          for col in ('+ @colsunpivot +')
        ) u
      ) unpiv
      pivot
      (
        max(value)
        for zone in ('+ @colspivot +')
      ) p'

exec(@query)

请参阅SQL Fiddle with Demo

所有版本都会产生相同的结果。

结果：

| COL | CENTRAL |  EAST | NORTH | SOUTH |  WEST |
-------------------------------------------------
|  M1 |    6233 |  3944 |  6233 | 12440 | 33736 |
|  M2 |    3636 | 14584 | 17743 | 20017 | 30532 |
|  M3 |       2 |     2 |     2 |     7 |     5 |
|  M4 |    6233 |   728 |  6233 |  8057 |  2184 |
|  M5 |    6717 |   953 |  6717 |  9724 |  2056 |
|  M6 |    6825 |   970 |  7369 | 13418 |  1944 |
|  M7 |    6825 |   970 |  7369 | 13418 |  1944 |

SQL查询：如何重新排列输出（Transpose？）

1 个答案: