SQL字符串分割解析

--方法一：动态SQL法

declare @s varchar(50),@sql varchar(300)
set @s=‘1,2,3,4,5,6,7,8,9,10‘
set @sql=‘select col=‘‘‘+ replace(@s,‘,‘,‘‘‘ union all select ‘‘‘)+‘‘‘‘
print @sql
exec (@sql)  

if exists (select * from dbo.sysobjects
where id = object_id(N‘[dbo].[f_splitSTR]‘) and xtype in (N‘FN‘, N‘IF‘, N‘TF‘))
drop function [dbo].[f_splitSTR]
GO  

--方法二：循环截取法

create function f_splitSTR(
    @s   varchar(8000),   --待分拆的字符串
    @split varchar(10)     --数据分隔符
)returns @re table(col varchar(100))
As
Begin
    Declare @splitlen int  --分隔符长度
    Set @splitlen=len(@split+‘a‘)-2
    While CharIndex(@split,@s)>0
    Begin
        Insert @re Values(left(@s,CharIndex(@split,@s)-1))
        --STUFF ( character_expression , start , length ,character_expression )
        Set @s=Stuff(@s,1,CharIndex(@split,@s)+@splitlen,‘‘)
        --Set @s = Substring(@s, CharIndex(@split,@s)[email protected], 100)
    End
    Insert @re Values(@s)
    return
End
GO  

if exists (select * from dbo.sysobjects
where id = object_id(N‘[dbo].[f_splitSTR]‘) and xtype in (N‘FN‘, N‘IF‘, N‘TF‘))
drop function [dbo].[f_splitSTR]
GO  

--方法三：使用临时性分拆辅助表法

Create function f_splitSTR(
    @s   varchar(8000),  --待分拆的字符串
    @split varchar(10)     --数据分隔符
)returns @re table(col varchar(100))
As
Begin
    --创建分拆处理的辅助表(用户定义函数中只能操作表变量)
    Declare @t table(ID int identity,b bit)
    Insert @t(b) Select top 8000 0 from syscolumns a,syscolumns b
    Insert @re Select SubString(@s,ID,CharIndex(@split,@s+@split,ID)-ID)
           from @t  Where ID<=len(@s+‘a‘) And CharIndex(@split,@split+@s,ID)=ID
    return
End
GO  

if exists (select * from dbo.sysobjects
where id = object_id(N‘[dbo].[f_splitSTR]‘) and xtype in (N‘FN‘, N‘IF‘, N‘TF‘))
drop function [dbo].[f_splitSTR]
GO
if exists (select * from dbo.sysobjects
where id = object_id(N‘[dbo].[tb_splitSTR]‘) and objectproperty(id,N‘IsUserTable‘)=1)
drop table [dbo].[tb_splitSTR]
GO  

--方法四：使用永久性分拆辅助表法  --字符串分拆辅助表

SELECT TOP 8000 ID=IDENTITY(int,1,1) INTO dbo.tb_splitSTR
FROM syscolumns a,syscolumns b
GO
--字符串分拆处理函数
Create function f_splitSTR(
    @s     nvarchar(8000),  --待分拆的字符串
    @split  nvarchar(10)     --数据分隔符
)returns table
As
    return(
        --cast类型转换函数 --CharIndex( exp1 , exp2 [,start_location])
        Select col=cast(SubString(@s,ID,CharIndex(@split,@s+@split,ID)-ID) as nvarchar(100))
        From tb_splitSTR  Where ID<=len(@s+‘a‘) and CharIndex(@split,@split+@s,ID)=ID)
GO  

--方法五：利用sql server2005的OUTER APPLY

Create function [dbo].[fn_Split]
(
  @str nvarchar(max) ,
  @split nvarchar(10)
  return table
  As
  return
    ( Select    B.id
      --Convert (data_type[(length)], expression [, style]) 类型转换
      From  ( Select  [value] = convert(XML , ‘<v>‘ + Replace(@str , @split , ‘</v><v>‘)
                     + ‘</v>‘) ) A
      Outer Apply ( Select  id = N.v.value(‘.‘ , ‘varchar(100)‘)
                    From  A.[value].nodes(‘/v‘) N ( v )
                  ) B
    ) 

--备注说明:  方法4必须在sql server2005下才可以运行