populate Dynamic pivot in Gridview

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

SELECT @ColumnName= ISNULL(@ColumnName + ',','') 
       + QUOTENAME(id)
FROM (SELECT DISTINCT id FROM Projects.COMPUTER_PARTS) AS Courses;


SET @DynamicPivotQuery = 
N'SELECT *
  FROM (
select a.id,C.COMPUTER_NAME, A.PART_NAME
from Projects.PARTS_ON_COMPUTERS P
left join Projects.COMPUTERS C ON C.Id= P.COMPUTER
LEFT JOIN Projects.COMPUTER_PARTS A ON A.Id= P.PART
	   ) s
  PIVOT (
         MAX(PART_NAME) FOR id IN  (' + @ColumnName + ')
		) p
';
EXEC sp_executesql @DynamicPivotQuery;