alter function test() Returns nvarchar(max) As Begin Declare @avg nvarchar(max) Declare @str nvarchar(max) Set @str=( Select ‘,‘+yuanshidanhao from Aj_Jibenxinxi Where convert(nvarchar(max),id) in (1,2,6) FOR XML PATH(‘‘) ) Return @str End
原文：http://www.cnblogs.com/chenghu/p/5062261.html