SQLServer 简单数据拆分

--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,'' + REPLACE([value], ',', '') + '') 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