Pivot in SQL Server with where clause - sql

Question

I am in need for using Pivot in SQL for getting the rows converted in columns, but not able to do so with my pivot query.
create table TestTable
(
id int,
colVal int
)
insert into TestTable values(1,1)
insert into TestTable values(1,2)
insert into TestTable values(1,4)
insert into TestTable values(2,1)
insert into TestTable values(2,2)
insert into TestTable values(2,6)
I am trying to get the values of colVal in the columns based on the below query where clause.
select * from
(
Select ID,colVal
from TestTable
where ID=1
) as PV
pivot
(max(id) for colVal in([1], [2], [3])) piv
For every ID there can only be 3 colValues hence I have specified [1],[2],[3] in the pivot.
I am looking for output like
ID c1 c2 c3
1 1 2 4
Can anyone help me out here.

Answer 1

Just use Row_Number() to create the column sequence
select id,[1] as c1,[2] as c2,[3] as c3 from
(
Select ID
,col = row_number() over (Partition By ID Order by colVal)
,colVal
from TestTable
where ID=1
) as PV
pivot
(max(colVal) for col in([1], [2], [3])) piv
Returns
ID c1 c2 c3
1 1 2 4
EDIT - Dynamic Version
Declare #SQL varchar(max) = Stuff((Select Distinct ',' + QuoteName(concat('C',row_number() over (Partition By ID Order by colVal)))
From TestTable
Order By 1
For XML Path('')
),1,1,'')
Select #SQL = '
Select [id],' + #SQL + '
From (
Select ID
,col = concat(''C'',row_number() over (Partition By ID Order by colVal))
,colVal
from TestTable
where ID=1
) A
Pivot (max(colVal) For [col] in (' + #SQL + ') ) p'
Exec(#SQL);
EDIT for 2008
Declare #SQL varchar(max) = Stuff((Select Distinct ',' + QuoteName('C'+cast(row_number() over (Partition By ID Order by colVal) as varchar(10)))
From TestTable
Order By 1
For XML Path('')
),1,1,'')
Select #SQL = '
Select [id],' + #SQL + '
From (
Select ID
,col = ''C''+cast(row_number() over (Partition By ID Order by colVal) as varchar(10))
,colVal
from TestTable
where ID=1
) A
Pivot (max(colVal) For [col] in (' + #SQL + ') ) p'
Exec(#SQL);