求SQL语句，将一列拆成多行

[佛祖的木鱼]

因为以前设计数据库时考虑不够周详，当用户输入多个产品编号时，系统是将其用逗号隔开保存到一个字段里，比如
ItemID InputUser InputItems
123 Test 2347,0967,2567

因为现在要用产品编号支链接其它的表，这样的话现有的表设计就非常的不合理了，现要求将其数据拆分到另一个表 B

ItemID InputItems
123 1347
123 0967
123 2567


考虑可以用循环来做，但考虑到表里有几万条数据，求一个有效的方式，谢谢。

[快乐_石头]

--合并分拆表
/******************************************************************************************************************************************************
合并分拆表数据

整理人：中国风(Roy)

日期:2008.06.06
******************************************************************************************************************************************************/

--> --> (Roy)生成測試數據
 
if not object_id('Tab') is null
    drop table Tab
Go
Create table Tab([Col1] int,[Col2] nvarchar(1))
Insert Tab
select 1,N'a' union all
select 1,N'b' union all
select 1,N'c' union all
select 2,N'd' union all
select 2,N'e' union all
select 3,N'f'
Go

合并表:

SQL2000用函数:

go
if object_id('F_Str') is not null
    drop function F_Str
go
create function F_Str(@Col1 int)
returns nvarchar(100)
as
begin
    declare @S nvarchar(100)
    select @S=isnull(@S+',','')+Col2 from Tab where Col1=@Col1
    return @S
end
go
Select distinct Col1,Col2=dbo.F_Str(Col1) from Tab

go

SQL2005用XML:

方法1:

select 
    a.Col1,Col2=stuff(b.Col2.value('/R[1]','nvarchar(max)'),1,1,'')
from 
    (select distinct COl1 from Tab) a
Cross apply
    (select COl2=(select N','+Col2 from Tab where Col1=a.COl1 For XML PATH(''), ROOT('R'), TYPE))b

方法2:

select 
    a.Col1,COl2=replace(b.Col2.value('/Tab[1]','nvarchar(max)'),char(44)+char(32),char(44))
from 
    (select distinct COl1 from Tab) a
cross apply
    (select Col2=(select COl2 from Tab  where COl1=a.COl1 FOR XML AUTO, TYPE)
                .query('<Tab>
                {for $i in /Tab[position()<last()]/@COl2 return concat(string($i),",")}
                {concat("",string(/Tab[last()]/@COl2))}
                </Tab>')
                )b

SQL05用CTE:

;with roy as(select Col1,Col2,row=row_number()over(partition by COl1 order by COl1) from Tab)
,Roy2 as
(select COl1,cast(COl2 as nvarchar(100))COl2,row from Roy where row=1 
union all 
select a.Col1,cast(b.COl2+','+a.COl2 as nvarchar(100)),a.row from Roy a join Roy2 b on a.COl1=b.COl1 and a.row=b.row+1)
select Col1,Col2 from Roy2 a where row=(select max(row) from roy where Col1=a.COl1) order by Col1 option (MAXRECURSION 0)


生成结果:
/*
Col1        COl2
----------- ------------
1           a,b,c
2           d,e
3           f

(3 行受影响)
*/


拆分表:

--> --> (Roy)生成測試數據
 
if not object_id('Tab') is null
    drop table Tab
Go
Create table Tab([Col1] int,[COl2] nvarchar(5))
Insert Tab
select 1,N'a,b,c' union all
select 2,N'd,e' union all
select 3,N'f'
Go

SQL2000用辅助表:
if object_id('Tempdb..#Num') is not null
    drop table #Num
go
select top 100 ID=Identity(int,1,1) into #Num from syscolumns a,syscolumns b
Select 
    a.Col1,COl2=substring(a.Col2,b.ID,charindex(',',a.Col2+',',b.ID)-b.ID) 
from 
    Tab a,#Num b
where
    charindex(',',','+a.Col2,b.ID)=b.ID --也可用 substring(','+a.COl2,b.ID,1)=','


SQL2005用Xml:

select 
    a.COl1,b.Col2
from 
    (select Col1,COl2=convert(xml,'<root><v>'+replace(COl2,',','</v><v>')+'</v></root>') from Tab)a
outer apply
    (select Col2=C.v.value('.','nvarchar(100)') from a.COl2.nodes('/root/v')C(v))b




SQL05用CTE:

;with roy as 
(select Col1,COl2=cast(left(Col2,charindex(',',Col2+',')-1) as nvarchar(100)),Split=cast(stuff(COl2+',',1,charindex(',',Col2+','),'') as nvarchar(100)) from Tab
union all
select Col1,COl2=cast(left(Split,charindex(',',Split)-1) as nvarchar(100)),Split= cast(stuff(Split,1,charindex(',',Split),'') as nvarchar(100)) from Roy where split>''
)
select COl1,COl2 from roy order by COl1 option (MAXRECURSION 0)

生成结果:
/*
Col1        COl2
----------- -----
1           a
1           b
1           c
2           d
2           e
3           f
*/

[百年树人]

[Quote=引用楼主 antherzhou 的帖子:]
因为以前设计数据库时考虑不够周详，当用户输入多个产品编号时，系统是将其用逗号隔开保存到一个字段里，比如
ItemID InputUser InputItems
123 Test 2347,0967,2567

因为现在要用产品编号支链接其它的表，这样的话现有的表设计就非常的不合理了，现要求将其数据拆分到另一个表 B

ItemID InputItems
123 1347
123 0967
123 2567


考虑可以用循环来做，但考虑到表里有几万条…
[/Quote]

---测试数据---
if object_id('[tb]') is not null drop table [tb]
go
create table [tb]([ItemID] int,[InputUser] varchar(4),[InputItems] varchar(14))
insert [tb]
select 123,'Test','2347,0967,2567'
 
---使用辅助表---
if object_id('Tempdb..#Num') is not null
    drop table #Num
go
select top 100 ID=Identity(int,1,1) into #Num from syscolumns a,syscolumns b

---查询---
Select 
    a.ItemID,InputItems=substring(a.InputItems,b.ID,charindex(',',a.InputItems+',',b.ID)-b.ID) 
from 
    tb a,#Num b
where
    charindex(',',','+a.InputItems,b.ID)=b.ID

drop table #Num

---结果---
ItemID      InputItems     
----------- -------------- 
123         2347
123         0967
123         2567

（所影响的行数为 3 行）

[dawugui]

/*
标题：分拆列值
作者：爱新觉罗.毓华(十八年风雨,守得冰山雪莲花开)
时间：2008-11-20
地点：广东深圳
描述

有表tb, 如下:
id          value
----------- -----------
1           aa,bb
2           aaa,bbb,ccc
欲按id,分拆value列, 分拆后结果如下:
id          value
----------- --------
1           aa
1           bb
2           aaa
2           bbb
2           ccc
*/

--1. 旧的解决方法(sql server 2000)
SELECT TOP 8000 id = IDENTITY(int, 1, 1) INTO # FROM syscolumns a, syscolumns b 

SELECT A.id, SUBSTRING(A.[values], B.id, CHARINDEX(',', A.[values] + ',', B.id) - B.id)
FROM tb A, # B
WHERE SUBSTRING(',' + A.[values], B.id, 1) = ','

DROP TABLE #

--2. 新的解决方法(sql server 2005) 
create table tb(id int,value varchar(30))
insert into tb values(1,'aa,bb')
insert into tb values(2,'aaa,bbb,ccc')
go
SELECT A.id, B.value
FROM(
    SELECT id, [value] = CONVERT(xml,'<root><v>' + REPLACE([value], ',', '</v><v>') + '</v></root>') FROM tb
)A
OUTER APPLY(
    SELECT value = N.v.value('.', 'varchar(100)') FROM A.[value].nodes('/root/v') N(v)
)B

DROP TABLE tb

/*
id          value
----------- ------------------------------
1           aa
1           bb
2           aaa
2           bbb
2           ccc

(5 行受影响)
*/

[dawugui]

create table tb(ItemID int, InputUser varchar(10), InputItems varchar(20))
insert into tb values(123 , 'Test' , '2347,0967,2567')
go

SELECT TOP 8000 id = IDENTITY(int, 1, 1) INTO # FROM syscolumns a, syscolumns b 

SELECT A.ItemID , InputItems = SUBSTRING(A.[InputItems], B.id, CHARINDEX(',', A.[InputItems] + ',', B.id) - B.id)
FROM tb A, # B
WHERE SUBSTRING(',' + A.[InputItems], B.id, 1) = ','

drop table tb , #

/*

ItemID      InputItems           
----------- -------------------- 
123         2347
123         0967
123         2567

（所影响的行数为 3 行）
*/

[pl_mm]

if object_id('tb') is not null
drop table tb
go
create table tb(ItemID varchar(50),InputUser varchar(50),InputItems varchar(50))
insert into tb select '123','Test','2347,0967,2567'
 
select ItemID,
InputItems=b.x.value('.','varchar(100)') 
from (select ItemID,InputItems=cast('<items><item>'+replace(InputItems,',','</item><item>')+'</item></items>' as xml) from tb) a
Cross apply 
a.InputItems.nodes('//item') as b(x)

ItemID InputItems
123 2347
123 0967
123 2567