利用xml改造以前在2000下的合并相同项目的函数
------------------------------------<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />
-- Author: happyflystone
-- Date:2008-11-23 22:17:36
-- Description:利用xml改造以前在2000下的合并相同项目的函数
------------------------------------
-- 运行环境：
SELECT @@version
/*
-------------------------------------------------
Microsoft SQL Server 2005 - 9.00.2047.00 (Intel X86)
Apr 14 2006 01:12:25
Copyright (c) 1988-2005 Microsoft Corporation
Standard Edition on Windows NT 5.0 (Build 2195: Service Pack 4)
(1 行受影响)
*/
-- Test Data: TA
IF OBJECT_ID('TA') IS NOT NULL
DROP TABLE TA
GO
CREATE TABLE TA(ID INT,DATA VARCHAR(50))
INSERT TA VALUES(1,'aa')
INSERT TA VALUES(1,'bb')
INSERT TA VALUES(1,'cc')
INSERT TA VALUES(2,'eee')
INSERT TA VALUES(2,'fff')
GO
-- 先来看看一个合并的例子：
CREATE FUNCTION F_STR(@ID INT)
RETURNS VARCHAR(100)
AS
BEGIN
DECLARE @S VARCHAR(100)
SELECT @S = ISNULL(@S+',','')
+DATA
FROM TA
WHERE ID = @ID
RETURN @S
END
GO
SELECT ID,DBO.F_STR(ID) AS COL
FROM TA
GROUP BY ID
/*
ID COL
----------- ----------------------------
1 aa,bb,cc
2 eee,fff
*/
DROP FUNCTION F_STR
GO
-- 下面我们利用XML来合并相同项，我们创建一个合并同类项的函数。
CREATE FUNCTION F_STR(@ID int)
RETURNS VARCHAR(100)
AS
BEGIN
DECLARE @x XML,@ret VARCHAR(100)
SET @x=
(SELECT DATA
FROM TA
WHERE ID = @ID
FOR XML PATH(''),ROOT('v'));
SELECT @ret = CAST(
@x.query('
<v>
{ for $i in //DATA
return concat(string($i),",")
}
</v>').value('/v[1]','VARCHAR(100)')
AS VARCHAR(100))
RETURN @ret
END
GO
-- 运行及结果，并删除函数
SELECT ID,DBO.F_STR(ID) AS COL
FROM TA
GROUP BY ID
/*
ID COL
----------- ----------------------------
1 aa,bb,cc
2 eee,fff
*/
DROP FUNCTION F_STR
-- 最后我贴上经常使用XML语法合并同类项一般SQL写法：
-- 1 (AUTO):
SELECT
ID,
[VALUES]=STUFF(REPLACE(REPLACE((SELECT DATA
FROM TA
WHERE ID=T.ID FOR XML AUTO),
'"/><TA DATA="',','),
'"/>',''),1,10,'')
FROM TA T
GROUP BY ID
-- 2:(OUTER APPLY,AUTO)
SELECT *
FROM(
SELECT DISTINCT
id
FROM ta
)A
OUTER APPLY(
SELECT
[bbb]= STUFF(REPLACE(REPLACE(
(
SELECT data FROM ta N
WHERE id = A.id
FOR XML AUTO
), '<N data="', ','), '"/>', ''), 1, 1, '')
)N
-- 3:(PATH)
SELECT
ID,
[VALUES]=STUFF((SELECT ','+LTRIM(DATA)
FROM TA T
WHERE ID=TA.ID FOR XML PATH('')), 1, 1, '')
FROM TA
GROUP BY ID
-- 上面的SQL运行结果都是一样，如下：
/*
ID
----------- ----------------------------
1 aa,bb,cc
2 eee,fff
*/