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--参考
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)=','
--2000不使用辅助表
Select
a.Col1,COl2=substring(a.Col2,b.number,charindex(',',a.Col2+',',b.number)-b.number)
from
Tab a join master..spt_values b
ON B.type='p' AND B.number BETWEEN 1 AND LEN(A.col2)
where
substring(','+a.COl2,b.number,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
*/
--子符串分解
/*
col
------------
aa,bb,cc,dd
要求
col
----
aa
bb
cc
dd
*/
create table tb(col varchar(100))
insert tb select 'aa,bb,cc,dd'
--",aa,bb,cc,dd" 利用此组逗号位置得出每个子串的第一个字符的位置,所以where条件中是','+col
--"aa,bb,cc,dd," 利用此组逗号位置得出每个子串的最后一个字符的位置,所以charindex函数中使用col+',' 计算出字符的最后位置
select *,substring(col,number,charindex(',',col+',',number)-number) from tb,master..spt_values
WHERE type='P' and substring(','+col,number,1)=',' and number<len(col)
--或者
select *,substring(col,number,charindex(',',col+',',number)-number) from tb,master..spt_values a
where type='p' and charindex(',',','+col,number)=number
drop table tb
--字符串快速分组(动态)
DECLARE @s NVARCHAR(1000)
SET @s='A,B,C,D,E,F,G'
SET @s='select '''+REPLACE(@s,',',''' union all select ''')+''''
print @s
EXEC(@s)
----
A
B
C
D
E
F
G
(7 行受影响)
--表tb 字段 code val 分隔符 ,
select code,substring(a.val,b.number,charindex(',',a.val+',',b.number)-b.number) val
from tb a,master..spt_values b
where b.[type] = 'p' and b.number between 1 and len(a.val)
and substring(','+a.val,b.number,1) = ','
--字符串快速分组(动态)
DECLARE @s NVARCHAR(1000)
SET @s='A,B,C,D,E,F,G'
SET @s='select '''+REPLACE(@s,',',''' union all select ''')+''''
print @s
EXEC(@s)