sql server 2008 数据的行转列

create table tb(id int, value varchar(10))

insert into tb values(1,'aa')

insert into tb values(1,'bb')

insert into tb values(2,'aaa')

insert into tb values(2,'bbb')

insert into tb values(2,'ccc')

GO

SELECT id,value = stuff ((SELECT     ',' + value FROM   tb AS t
    WHERE     t .id = tb.id FOR xml path('')), 1, 1, '')
FROM  tb
GROUP BY id