求一视图能达到下面所示结果:drop table #t
create table #t
(
id varchar(20),
cols varchar(100)
)
insert into #t
select '1','a,b'
union all
select '2','c,d,e'select * from #t--视图结果
select '1','a'
union all
select '1','b'
union all
select '2','c'
union all
select '2','d'
union all
select '2','e'
(2 行受影响)
id cols
-------------------- ----------------------------------------------------------------------------------------------------
1 a,b
2 c,d,e(2 行受影响)
---- ----
1 a
1 b
2 c
2 d
2 e(5 行受影响)
create table #t
(
id varchar(20),
cols varchar(100)
)
insert into #t
select '1','a,b'
union all
select '2','c,d,e'select * from #t--视图结果
select '1','a'
union all
select '1','b'
union all
select '2','c'
union all
select '2','d'
union all
select '2','e'
(2 行受影响)
id cols
-------------------- ----------------------------------------------------------------------------------------------------
1 a,b
2 c,d,e(2 行受影响)
---- ----
1 a
1 b
2 c
2 d
2 e(5 行受影响)
标题:简单数据拆分(version 2.0)
作者:爱新觉罗.毓华(十八年风雨,守得冰山雪莲花开)
时间:2010-05-07
地点:重庆航天职业学院
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)create table tb(id int,value varchar(30))
insert into tb values(1,'aa,bb')
insert into tb values(2,'aaa,bbb,ccc')
go--方法1.使用临时表完成
SELECT TOP 8000 id = IDENTITY(int, 1, 1) INTO # FROM syscolumns a, syscolumns b SELECT A.id, value = SUBSTRING(A.[value], B.id, CHARINDEX(',', A.[value] + ',', B.id) - B.id)
FROM tb A, # B
WHERE SUBSTRING(',' + A.[value], B.id, 1) = ','DROP TABLE #--方法2.如果数据量小,可不使用临时表
select a.id , value = substring(a.value , b.number , charindex(',' , a.value + ',' , b.number) - b.number)
from tb a join master..spt_values b
on b.type='p' and b.number between 1 and len(a.value)
where substring(',' + a.value , b.number , 1) = ','--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--方法1.使用xml完成
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--方法2.使用CTE完成
;with tt as
(select id,[value]=cast(left([value],charindex(',',[value]+',')-1) as nvarchar(100)),Split=cast(stuff([value]+',',1,charindex(',',[value]+','),'') as nvarchar(100)) from tb
union all
select id,[value]=cast(left(Split,charindex(',',Split)-1) as nvarchar(100)),Split= cast(stuff(Split,1,charindex(',',Split),'') as nvarchar(100)) from tt where split>''
)
select id,[value] from tt order by id option (MAXRECURSION 0)
DROP TABLE tb/*
id value
----------- ------------------------------
1 aa
1 bb
2 aaa
2 bbb
2 ccc(5 行受影响)
*/
如果是表:
create table tb
(
id varchar(20),
cols varchar(100)
)
insert into tb
select '1','a,b'
union all
select '2','c,d,e'
go
create view splittb as
SELECT A.id, SUBSTRING(A.[cols], B.id, CHARINDEX(',', A.[cols] + ',', B.id) - B.id) cols
FROM tb A,(select id=(select count(*) from(select distinct id from sysobjects)t1 where id<t2.id)+1 from (select distinct id from sysobjects)t2
)B WHERE SUBSTRING(',' + A.[cols], B.id, 1) = ','
go
select * from splittb
/*
id cols
-------------------- ----------------------------------------------------------------------------------------------------
1 a
2 c
1 b
2 d
2 e(5 行受影响)
*/
go
DROP TABLE tb
drop view splittb