Dynamic Pivot (row to columns)

问题

I have a Table1:

ID Instance Name Size Tech
 1   0       D1  123   ABC
 1   1       D2  234   CDV
 2   2       D3  234   CDV
 2   3       D4  345   SDF

I need the resultset using Dynamic PIVOT to look like along with the headers:

ID | Instance0_Name | Instance0_Size | Instance0_Tech | Instance1_Name | Instance1_Size | Instance1_tech
1  | D1             | 123            | ABC            | D2             | 234            | CDV

Any help would be appreciated. using Sql Server 2008.

Sorry for the earlier post.

回答1:

Your desired output is not exactly clear, but you can use the both the UNPIVOT and PIVOT function to get the result

If you know the number of columns, then you can hard code the values:

select *
from
(
  select id, 
    'Instance'+cast(instance as varchar(10))+'_'+col col, 
    value
  from 
  (
    select id, 
      Instance, 
      Name, 
      cast(Size as varchar(50)) Size,
      Tech
    from yourtable
  ) x
  unpivot
  (
    value
    for col in (Name, Size, Tech)
  ) u
) x1
pivot
(
  max(value) 
  for col in
    ([Instance0_Name], [Instance0_Size], [Instance0_Tech], 
     [Instance1_Name], [Instance1_Size], [Instance1_Tech], 
     [Instance2_Name], [Instance2_Size], [Instance2_Tech], 
     [Instance3_Name], [Instance3_Size], [Instance3_Tech])
) p

See SQL Fiddle with Demo

Then if you have an unknown number of values, you can use dynamic sql:

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

select @colsPivot = STUFF((SELECT ',' 
                      + quotename('Instance'+ cast(instance as varchar(10))+'_'+c.name)
                    from yourtable t
                    cross apply sys.columns as C
                    where C.object_id = object_id('yourtable') and
                         C.name not in ('id', 'instance')
                    group by t.instance, c.name
                    order by t.instance
            FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)') 
        ,1,1,'')


set @query 
  = 'select *
      from
      (
        select id, 
          ''Instance''+cast(instance as varchar(10))+''_''+col col, 
          value
        from 
        (
          select id, 
            Instance, 
            Name, 
            cast(Size as varchar(50)) Size,
            Tech
          from yourtable
        ) x
        unpivot
        (
          value
          for col in (Name, Size, Tech)
        ) u 
      ) x1
      pivot
      (
        max(value)
        for col in ('+ @colspivot +')
      ) p'

exec(@query)

See SQL Fiddle with Demo

If the result is not correct, then please edit your OP and post the result that you expect from both of the Ids you provided.

来源：https://stackoverflow.com/questions/14224371/dynamic-pivot-row-to-columns

标签

sql

sql-server

sql-server-2008

pivot

unpivot