sql - Transposing a column values into column headers -

i have table this:

+-------------+-----------+------------+ | sample_name | test_name | test_value | +-------------+-----------+------------+ | s1          | t1        | 1.5        | | s2          | t2        | 3          | | s3          | t1        | 8          | | s4          | t3        | 5          | +-------------+-----------+------------+ 

and want put test_names column headers this

+-------------+------+------+------+ | sample_name |  t1  |  t2  |  t3  | +-------------+------+------+------+ | s1          | 1.5  | null | null | | s2          | null | 3    | null | | s3          | 8    | null | null | | s4          | null | null | 5    | +-------------+------+------+------+ 

i have come convoluted solution using temporary table, dynamic sql , while loops slow , know, there way select?

thanks

if there values test_name may use pivot within dynamic sql:

declare @names varchar(max)  select @names = coalesce(@names + ', ', '') + test_name  (select distinct test_name tbl) t  exec(' select * tbl t  pivot (sum(test_value)         test_name          in ('+@names+'))p') 

sqlfiddle demo