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
