SQL Server - Rows to Columns without Aggregation

Question

I have data that looks like this:

address      | id  
12AnyStreet  | 1234  
12AnyStreet  | 1235  
12AnyStreet  | 1236  
12AnyStreet  | 1237 

Answer 1

You can transform this data using the PIVOT function in SQL Server. In order to PIVOT the data, you will want to create your new column using the row_number().

If you have a known number of values, then you can hard-code the query:

select *
from
(
  select address, id,
    'id_'+cast(row_number() over(partition by address 
                                order by id) as varchar(20)) rn
  from yourtable
) src
pivot
(
  max(id)
  for rn in ([id_1], [id_2], [id_3], [id_4])
) piv

See SQL Fiddle with Demo

But if the values are unknown then you will need to use dynamic SQL:

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

select @cols = STUFF((SELECT distinct ',' 
                      + QUOTENAME(rn) 
                    from
                    (
                      select 'id_'+cast(row_number() over(partition by address 
                                order by id) as varchar(20)) rn
                      from yourtable
                    ) src
            FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)') 
        ,1,1,'')

set @query = 'SELECT address,' + @cols + ' from 
             (
                select address, id,
                  ''id_''+cast(row_number() over(partition by address 
                                              order by id) as varchar(20)) rn
                from yourtable
            ) x
            pivot 
            (
                max(id)
                for rn in (' + @cols + ')
            ) p '

execute(@query)

See SQL Fiddle with Demo

The result of both queries is:

|     ADDRESS | ID_1 | ID_2 | ID_3 | ID_4 |
-------------------------------------------
| 12AnyStreet | 1234 | 1235 | 1236 | 1237 |