Sqlserver Stuff函数

DECLARE @TAB TABLE
(
       UserID INT,
       UserName NVARCHAR(50)
)
INSERT INTO @TAB
(
    UserID,
    UserName
)
VALUES
(0,N'西门炊鳕'),
(1,N'夜雇乘'),
(2,N'令狐冲'),
(3,N'士兵甲'),
(4,N'胡学'),
(5,N'五道口'),
(6,N'六道口')
--目的.将用户名用分隔符','隔开.最后得出字符:"西门炊鳕,夜雇乘,令狐冲,士兵甲,胡学,五道口,六道口"
--最终的Sql语句猛一看,有点懵,下面分解开来一步步说.
SELECT STUFF
(
(SELECT ','+UserName FROM @TAB FOR XML PATH('')),
1,
1,
''
)
--SELECT *FROM @TAB
--FOR XML PATH('')
SELECT UserName FROM @TAB FOR XML PATH('')
--FOR XML PATH('')之加个分隔符','
SELECT ','+UserName FROM @TAB FOR XML PATH('')
--Stuff将第一个分隔符','截取
SELECT STUFF
(
(SELECT ','+UserName FROM @TAB FOR XML PATH('')),
1,
1,
''
)
--Stuff将第一个分隔符'***'截取
SELECT STUFF
(
(SELECT '***'+UserName FROM @TAB FOR XML PATH('')),
1,
3,
''
)