SQL Server GROUP BY 后 拼接 字符串

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

--测试    SQL GROUP 组字符串拼接
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

--查看重复的构件编码
SELECT * FROM (
    SELECT 
        NCOMPONENTCODE,
        COUNT(1) AS RepeatNum,
        --分部分项名称
        STUFF(
        (
            SELECT 
            ',' + PROJECTNAME 
            FROM TB_PROJECTS10 
            WHERE NCOMPONENTCODE = a.NCOMPONENTCODE 
            FOR XML PATH('')
        )
        ,1,1,'') AS 'PROJECTNAME 分部分项名称 多个以逗号隔开'
    FROM dbo.TB_PROJECTS10 a
    GROUP BY NCOMPONENTCODE
) T ORDER BY RepeatNum DESC