sqlserver 拆分

发布时间:2019-01-09  栏目:SQL  评论:0 Comments

有表tb, 如下:
id value

–方法0:动态SQL法


declare @s varchar(100),@sql varchar(1000)
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)

--方法1:循环截取法

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
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
 SET @splitlen=LEN(@split+'a')-2
 WHILE CHARINDEX(@split,@s)>0
 BEGIN
  INSERT @re VALUES(LEFT(@s,CHARINDEX(@split,@s)-1))
  SET @s=STUFF(@s,1,CHARINDEX(@split,@s)+@splitlen,'')
 END
 INSERT @re VALUES(@s)
 RETURN
END
GO

1 aa,bb
2 aaa,bbb,ccc
欲按id,分拆value列, 分拆后结果如下:
id value

 –方法2:使用暂行分拆帮助表法


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
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

1 aa
1 bb
2 aaa
2 bbb
2 ccc

 –方法3:使用永久性分拆帮助表法

–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

--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     varchar(8000),  --待分拆的字符串
@split  varchar(10)     --数据分隔符
)RETURNS TABLE
AS
RETURN(
 SELECT col=CAST(SUBSTRING(@s,ID,CHARINDEX(@split,@s+@split,ID)-ID) as varchar(100))
 FROM tb_splitSTR
 WHERE ID<=LEN(@s+'a') 
  AND CHARINDEX(@split,@split+@s,ID)=ID)
GO

–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)

 –方法4:利用sql server2005的OUTER
APPLY

DROP TABLE tb

CREATE FUNCTION [dbo].[ufn_SplitStringToTable]
(
  @str VARCHAR(MAX) ,
  @split VARCHAR(10)
)
RETURNS TABLE
    AS 
RETURN
    ( SELECT    B.id
      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
    )

备注表达:

措施4不可以不在sql server2005下才方可运行

 

转:aierong原创技术小说  sqlserver字符串拆分(split)方法汇总

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