sql server - comma delimited list as a single string, T-SQL

My T-SQL query generates following result set

ID        Date
756 2011-08-29

756 2011-08-31
756 2011-09-01
756 2011-09-02

How can I convert like this

ID                Date
756 2011-08-29, 2011-08-31, 2011-09-01, 2011-09-02

Any suggestion would be appreciated.

Answer

You could use FOR XML PATH and STUFF to concatenate the multiple rows into a single row:

select distinct t1.id,
  STUFF(
         (SELECT ', ' + convert(varchar(10), t2.date, 120)
          FROM yourtable t2
          where t1.id = t2.id

          FOR XML PATH (''))
          , 1, 1, '')  AS date
from yourtable t1;

See SQL Fiddle with Demo