原文地址：https://blog.csdn.net/u010673842/article/details/79637618

select  ID, 
STUFF((select ',' + name from  class where ID = a.ID for xml path('')),1,1,'')
from class a group by ID

--測試    SQL GROUP 組字串拼接
SELECT
    NCOMPONENTCODE, 
    STUFF((select ',' + NCOMPONENTCODE from  TB_PROJECTS10 where
 
 NCOMPONENTCODE = a.NCOMPONENTCODE for xml path('')),1,1,'') AS NCOMPONENTCODES,
    STUFF((select ',' + PROJECTNAME from  TB_PROJECTS10 where NCOMPONENTCODE = a.NCOMPONENTCODE for xml path('')),1,1,'') AS PROJECTNAMES
from TB_PROJECTS10 a group by NCOMPONENTCODE

--檢視重複的構件編碼
SELECT * FROM (
    
 
SELECT 
        NCOMPONENTCODE,
        COUNT(1) AS RepeatNum,
        --分部分項名稱
        STUFF(
        (
            SELECT 
            ',' + PROJECTNAME 
            FROM TB_PROJECTS10 
            WHERE NCOMPONENTCODE = a.NCOMPONENTCODE 
            FOR XML PATH('')
        )
        ,1,1,'') AS '
 
PROJECTNAME 分部分項名稱 多個以逗號隔開'
    FROM dbo.TB_PROJECTS10 a
    GROUP BY NCOMPONENTCODE
) T ORDER BY RepeatNum DESC