Concatenate rows into a single column

From web site http://blogs.technet.com/b/wardpond/archive/2008/03/13/database-programming-the-string-concatenation-xml-trick.aspx


create table Parent
(
ParentID INT
,ParentString VARCHAR(100)
)

INSERT Parent VALUES (1, 'Parent 1 String')
INSERT Parent VALUES (2, 'Parent 2 String')
INSERT Parent VALUES (3, 'Parent 3 String')


SELECT Parent.ParentString
FROM Parent

-- PERFORM THE TRICK
-- PIVOT Parent VALUES INTO 1 COLUMN FOR 1 BASE ROW
SELECT STUFF(( SELECT [text()]= ',' + ISNULL(Parent.ParentString, '') + ''
FROM Parent
ORDER BY Parent.ParentString
FOR XML PATH('')), 1,1, '') AS Parent_CSV