（3）合并列值与分拆列值

CREATE TABLE t_Demo1
(
  Id INT,
  Data VARCHAR(30)
)
GO

INSERT INTO t_Demo1 VALUES(1,'aa,bb') 
INSERT INTO t_Demo1 VALUES(2,'aaa,bbb,ccc')

--方法一：适用于SQL 2000
SELECT TOP 8000 id = IDENTITY(int, 1, 1) INTO #t FROM syscolumns a, syscolumns b

SELECT A.Id, SUBSTRING(A.Data, B.Id, CHARINDEX(',', A.Data + ',', B.Id) - B.Id) AS Data
FROM t_Demo1 as A, #t as B 
WHERE SUBSTRING(',' + A.Data, B.Id, 1) = ',' 

DROP TABLE #t

--方法二：适用于SQL 2005及之后版本
SELECT A.Id, B.Data 
FROM( 
    SELECT Id, Data = CONVERT(xml,' <root> <v>' + REPLACE(Data, ',', ' </v> <v>') + ' </v> </root>') FROM t_Demo1 
)A 
OUTER APPLY( 
    SELECT Data = N.v.value('.', 'varchar(100)') FROM A.Data.nodes('/root/v') N(v) 
)B 

REATE TABLE t_Demo2
(
  Id INT,
  Data VARCHAR(30)
)
GO
INSERT INTO t_Demo2 VALUES(1, 'aa') 
INSERT INTO t_Demo2 VALUES(1, 'bb') 
INSERT INTO t_Demo2 VALUES(2, 'aaa') 
INSERT INTO t_Demo2 VALUES(2, 'bbb') 
INSERT INTO t_Demo2 VALUES(2, 'ccc') 

--方法一（适用于SQL2000 版本只能用函数的方式来实现）:
CREATE FUNCTION dbo.Fun_GetStr(@id INT) 
RETURNS VARCHAR(8000) 
AS 
BEGIN 
 DECLARE @r VARCHAR(8000) 
 SET @r = '' 
 SELECT @r = @r + ',' + CAST(Data AS VARCHAR) FROM t_Demo2 WHERE id=@id 
 SET @r=STUFF(@r, 1, 1, '')
 --或者
 --SET @r=RIGHT(@r , len(@r) - 1) 
 RETURN @r
END 
GO
--使用该函数
SELECT Id, Data = dbo.Fun_GetStr(Id) FROM t_Demo2 GROUP BY Id
--或者
SELECT DISTINCT Id ,dbo.Fun_GetStr(Id) AS Data FROM t_Demo2 
--删除该函数
DROP FUNCTION dbo.Fun_GetStr
GO

--方法二(适用于SQL2005及其以后版本)
SELECT Id, Data=STUFF((SELECT ','+ Data FROM t_Demo2 AS t WHERE Id=t_Demo2.Id FOR XML PATH('')), 1, 1, '') 
FROM t_Demo2 
GROUP BY Id 

CREATE TABLE t_Price
(
  Id INT,
  Salary FLOAT, 
  Name NVARCHAR(10)
)
GO

INSERT INTO t_Price VALUES(1,10,'小明')
INSERT INTO t_Price VALUES(1,20,'小红')
INSERT INTO t_Price VALUES(2,50,'小兰')
INSERT INTO t_Price VALUES(2,100,'小七')
GO

--方法一:(利用函数)
CREATE FUNCTION Fun_HbStr(@id int)
 RETURNS NVARCHAR(100)
AS
BEGIN
    DECLARE @s NVARCHAR(100)
    SELECT @s=ISNULL(@s+',','')+ CAST(Name AS NVARCHAR) FROM t_Price where id=@id
    RETURN @s
END
GO
SELECT Id ,SUM(Salary) AS Salary,dbo.Fun_HbStr(Id) AS Data FROM t_Price GROUP BY Id
--删除函数
DROP FUNCTION Fun_HbStr
GO
--方法二：
SELECT Id, SUM(Salary) AS Salary,name=STUFF((SELECT ','+ Name FROM t_Price AS t WHERE Id=t_Price.Id FOR XML PATH('')), 1, 1, '') 
FROM t_Price 
GROUP BY Id 

--删除表 t_Price
DROP TABLE t_Price
GO