午夜国产狂喷潮在线观看|国产AⅤ精品一区二区久久|中文字幕AV中文字幕|国产看片高清在线

一.定義表變量

代碼如下:

DECLARE @T1 table

(

UserID int ,

UserName nvarchar(50),

CityName nvarchar(50)

);

insert into @T1 (UserID,UserName,CityName) values (1,'a','上海')

insert into @T1 (UserID,UserName,CityName) values (2,'b','北京')

insert into @T1 (UserID,UserName,CityName) values (3,'c','上海')

insert into @T1 (UserID,UserName,CityName) values (4,'d','北京')

insert into @T1 (UserID,UserName,CityName) values (5,'e','上海')

select * from @T1

-----最優(yōu)的方式

SELECT CityName,STUFF((SELECT ',' + UserName FROM @T1 subTitle WHERE CityName=A.CityName FOR XML PATH('')),1, 1, '') AS A

FROM @T1 A

GROUP BY CityName

----第二種方式

SELECT B.CityName,LEFT(UserList,LEN(UserList)-1)

FROM (

SELECT CityName,(SELECT UserName+',' FROM @T1 WHERE CityName=A.CityName FOR XML PATH('')) AS UserList

FROM @T1 A

GROUP BY CityName

) B

stuff(select ',' + fieldname from tablename for xml path('')),1,1,'')

這一整句的作用是將多行fieldname字段的內(nèi)容串聯(lián)起來，用逗號(hào)分隔。

for xml path是SQL Server 2005以后版本支持的一種生成XML的方式。

stuff函數(shù)的作用是去掉字符串最前面的逗號(hào)分隔符。

更多信息請(qǐng)查看IT技術(shù)專欄