SQL 分组聚合字符串

SELECT TAG_TYPE,TAG_DESC 
FROM dbo.RPT_TAGMASTER
FOR XML PATH('') 

SELECT TAG_TYPE,VALUE=STUFF(
	(SELECT ','+TAG_DESC 
	FROM RPT_TAGMASTER X
	WHERE X.TAG_TYPE=Y.TAG_TYPE
	FOR XML PATH('')), 1 , 1 , '')
FROM RPT_TAGMASTER Y
GROUP BY Y.TAG_TYPE
SELECT TAG