SQL Server: How can I group multiple row values into separate columns?

Question

I am attempting to create a SELECT query that will allow me to combine multiple phone numbers for a Contact into separate columns.

For example, I would

Answer 1

Here is a dynamic pivot way:

declare @table table (Email varchar(64), Phone varchar(16), ID varchar(3))
insert into @table
values

('x@x.com','555-5555','001'),
('x@x.com','555-5556','001'),
('x@x.com','555-5557','001'),
('x@x.com','555-5558','001'),
('x@xdd.com','333-5556','002'),
('x@xdd.com','444-5556','002'),
('x@xdd.com','777-5556','002')


select
    Email
    ,Phone
    ,ID
    ,row_number() over (partition by ID order by Phone) as RN
into #staging
from 
    @table




DECLARE @DynamicPivotQuery AS NVARCHAR(MAX)
DECLARE @ColumnName AS NVARCHAR(MAX)

--Get distinct values of the PIVOT Column 
SELECT @ColumnName= ISNULL(@ColumnName + ',','') 
       + QUOTENAME(RN)
FROM (SELECT DISTINCT RN FROM #staging) AS RN

--Prepare the PIVOT query using the dynamic 
SET @DynamicPivotQuery = 
  N'SELECT Email, ID, ' + @ColumnName + '
    FROM #staging
    PIVOT(MAX(Phone) 
          FOR RN IN (' + @ColumnName + ')) AS PVTTable'
--Execute the Dynamic Pivot Query
EXEC sp_executesql @DynamicPivotQuery

drop table #staging

If you are only expecting 3, as you stated, you can skip the dynamic...

declare @table table (Email varchar(64), Phone varchar(16), ID varchar(3))
insert into @table
values

('x@x.com','555-5555','001'),
('x@x.com','555-5556','001'),
('x@xdd.com','333-5556','002'),
('x@xdd.com','444-5556','002'),
('x@xdd.com','777-5556','002')

;with cte as(
select
    Email
    ,Phone
    ,ID
    ,row_number() over (partition by ID order by Phone) as RN
from 
    @table)

select
    Email
    ,max(case when RN = 1 then Phone end) as Phone1
    ,max(case when RN = 2 then Phone end) as Phone2
    ,max(case when RN = 3 then Phone end) as Phone3
    ,ID
from
    cte
group by
    Email
    ,ID