SQL FOR XML Path 的用法

DECLARE @ProjectTempTable TABLE(BelongedTo VARCHAR(50),RecordNumber VARCHAR(50),UserName VARCHAR(50))
INSERT INTO @ProjectTempTable (BelongedTo,RecordNumber,UserName)
SELECT tmp.BelongedTo,tmp.RecordNumber,au.UserName FROM (
                SELECT aup.BelongedTo,aup.RecordNumber FROM dbo.App_UserInfo AS au
                LEFT  JOIN dbo.App_UserProInfo AS aup
                ON au.UserNumber = aup.UserNumber        
                WHERE au.UserCardID ='320882199206285699' AND (au.AccountTypes<>'' OR au.AccountTypes IS NOT NULL )
                ) AS tmp
                LEFT JOIN App_UserProInfo AS aup
                ON tmp.BelongedTo = aup.BelongedTo AND tmp.RecordNumber = aup.RecordNumber
                LEFT JOIN dbo.App_UserInfo AS au
                ON aup.UserNumber = au.UserNumber
                
SELECT * FROM @ProjectTempTable

上面查詢的語句結果如下圖:

現在要將 相同的BelongedTo,RecordNumber的UserName字段合並到一起去。

SELECT B.RecordNumber,B.BelongedTo,LEFT(StuList,LEN(StuList)-1) as UserName FROM (
SELECT BelongedTo,RecordNumber,
(SELECT UserName+',' FROM @ProjectTempTable 
  WHERE RecordNumber=A.RecordNumber AND BelongedTo=A.BelongedTo
  FOR XML PATH('')) AS StuList
FROM @ProjectTempTable A 
GROUP BY  RecordNumber,BelongedTo
) B 

查詢結果如下圖：

這里我聲明了一個變量表,是為了下面的合並的時候看起簡介點