Wayne,

Can you provide more explanation on this part of the query:

TYPE).value('.','varchar(max)')

I have always used:

WITH CTE AS

(

SELECT DISTINCT

AccountNumber

FROM #TestData

)

SELECT AccountNumber,

CommaList = STUFF((

SELECT ',' + Value

FROM #TestData

WHERE AccountNumber = CTE.AccountNumber

ORDER BY Value

FOR XML PATH('')),1,1,'') -- no TYPE.value

FROM CTE;

This provides the same results as your query.