日期:2014-05-18  浏览次数:20545 次

select max(node) from .....
select max(node) from .....
 如果node数据库存的是字符串,怎么取这个node的最大值???

------解决方案--------------------
SQL code

--各种字符串分函数

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

--3.2.1 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
    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


/*==============================================*/

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

--3.2.3.1 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

--3.2.3.2 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     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


/*==============================================*/

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

--3.2.5 将数据项按数字与非数字再次拆份
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(No varchar(100),Value varchar(20))
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    No=REVERSE(STUFF(col,1,PATINDEX('%[^-^.^0-9]%',col+'a')-1,'')),
        Value=REVERSE(LEFT(col,PATINDEX('%[^-^.^0-9]%',col+'a')-1))
    FROM(
        SELECT col=REVERSE(SUBSTRING(@s,ID,CHARINDEX(@split,@s+@split,ID)-ID))
        FROM @t
        WHERE ID<=LEN(@s+'a') 
            AND CHARINDEX(@split,@split+@s,ID)=ID)a
    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

--3.2.6 分拆短信数据
CREATE FUNCTION f_splitSTR(@s varchar(8000))
RETURNS @re TABLE(split varchar(10),value varchar(100))
AS
BEGIN
    DECLARE @splits TABLE(split varchar(10),splitlen as LEN(split))
    INSERT @splits(split)
    SELECT 'AC' UNION ALL
    SELECT 'BC' UNION ALL
    SELECT 'CC' UNION ALL
    SELECT 'DC'    
    DECLARE @pos1 int,@pos2 int,@split varchar(10),@splitlen int
    SELECT TOP 1 
        @pos1=1,@split=split,@splitlen=splitlen
    FROM @splits
    WHERE @s LIKE split+'%'
    WHILE @pos1>0
    BEGIN
        SELECT TOP 1
            @pos2=CHAR