当前位置: 首页 > 图文教程 > 数据库 > MSSQL > 讲解SQL Server2005数据项的分拆与合并

MSSQL
SQL Server SA权限总结经典技术
ASP数据库编程SQL常用技巧
SQL SERVER数据库开发之存储过程应用
SQL Server 2000的安全配置
MSSQL经典语句
SQL 经典语句
有用的SQL语句(删除重复记录,收缩日志)
Access 数据类型与 MS SQL 数据类型的相应
SQL语句示例
SQL数据类型详解
将Sql Server对象的当前拥有者更改成目标拥有者
MSSQL内外连接(INNER JOIN)语句详解
SQL 外链接操作小结 inner join left join right join
SQL Server中网络备份一例
SQL语句导入导出大全
SQL 新增/修改 表字段列的类型等
系统存储过程,sp_executesql
sql2005开启xp_cmdshell
实例学习SQL的Select命令
删除数据库中重复数据的几个方法

MSSQL 中的 讲解SQL Server2005数据项的分拆与合并


出处:互联网   整理: 软晨网(RuanChen.com)   发布: 2009-10-17   浏览: 129 ::
收藏到网摘: n/a

SQL Server2005数据项的分拆与合并:

参考示例如下:

-- =============================================

-- Author: LzmTW

-- Create date: 20080102

-- Description: 连接子字符串

-- @TableName: 数据所在的表的名称

-- @KeyColName: 连接子字符串所依据的键值所在的列

-- @JoinColName: 包含要连接的子字符串所在的列

-- @Quote: 分隔子字符串

-- @Where: 选择条件,不包含Where

-- =============================================

CREATE PROCEDURE [Helper].[JoinValue]

@TableName nvarchar(100)

,@KeyColName nvarchar(20)

,@JoinColName nvarchar(20)

,@Quote nvarchar(10) = N','

,@Where nvarchar(max) = NULL

AS

BEGIN

SET NOCOUNT ON;

DECLARE

@SQL nvarchar(max)

IF @Where IS NULL

SET @SQL = N'

SELECT *

FROM

(

SELECT DISTINCT KeyCol = @KeyColName

FROM @TableName

)a

'

ELSE

SET @SQL = N'

SELECT *

FROM

(

SELECT DISTINCT KeyCol = @KeyColName

FROM @TableName

WHERE @Where

)a

'

SET @SQL = @SQL + N'

OUTER APPLY (

SELECT NewValues =

STUFF(

REPLACE(

REPLACE(

REPLACE(

(

SELECT JoinCol = @JoinColName

FROM @TableName b

WHERE @KeyColName = a.KeyCol

FOR XML RAW

)

, N'''', N'''')

, N'', N''"/>'', N'''')

, 1, LEN(N''@Quote''), N'''')

) c'


SET @SQL = REPLACE(@SQL, N'@TableName', @TableName)

SET @SQL = REPLACE(@SQL, N'@KeyColName', @KeyColName)

SET @SQL = REPLACE(@SQL, N'@JoinColName', @JoinColName)

SET @SQL = REPLACE(@SQL, N'@Quote', @Quote)

IF NOT @Where IS NULL

SET @SQL = REPLACE(@SQL, N'@Where', @Where)


--PRINT @SQL

EXEC sp_executesql @SQL

END


GO


-- =============================================

-- Author: LzmTW

-- Create date: 20080102

-- Description: 分拆字符串

-- @TableName: 数据所在的表的名称

-- @KeyColName: 分拆为子字符串所依据的键值所在的列

-- @SpliteColName: 包含要分拆的字符串所在的列

-- @Quote: 分隔子字符串

-- @Where: 选择条件,不包含Where

-- =============================================

CREATE PROCEDURE [Helper].[SpliteValues]

@TableName nvarchar(100)

,@KeyColName nvarchar(20)

,@SpliteColName nvarchar(20)

,@Quote nvarchar(10) = N','

,@Where nvarchar(max) = NULL

AS

BEGIN

SET NOCOUNT ON;

DECLARE

@SQL nvarchar(max)

IF @Where IS NULL

SET @SQL = N'

SELECT

KeyCol, NewValue

FROM

(

SELECT

KeyCol = @KeyColName

,SpliteCol = CONVERT(xml, N'''' + REPLACE(@SpliteColName, N''@Quote'', N'''') + N'''')

FROM @TableName

) a

'

ELSE

SET @SQL = N'

SELECT

KeyCol, NewValue

FROM

(

SELECT

KeyCol = @KeyColName

,SpliteCol = CONVERT(xml, N'''' + REPLACE(@SpliteColName, N''@Quote'', N'''') + N'''')

FROM @TableName

WHERE @Where

) a

'

SET @SQL = @SQL + N'

OUTER APPLY

(

SELECT NewValue = N.v.value(N''.'', ''nvarchar(max)'')

FROM SpliteCol.nodes(N''/root/v'') N(v)

) b'

SET @SQL = REPLACE(@SQL, N'@TableName', @TableName)

SET @SQL = REPLACE(@SQL, N'@KeyColName', @KeyColName)

SET @SQL = REPLACE(@SQL, N'@SpliteColName', @SpliteColName)

SET @SQL = REPLACE(@SQL, N'@Quote', @Quote)

IF NOT @Where IS NULL

SET @SQL = REPLACE(@SQL, N'@Where', @Where)

EXEC sp_executesql @Sql

END

示例:


SET NOCOUNT ON

CREATE TABLE ##Table([keyCol] varchar(3), [NewValues] varchar(max))


--原数据

SELECT

[title_id]

,[title]

FROM [pubs].[dbo].[titles]

WHERE [type] LIKE 'p%'

--以title_id的前两个字符为参考键值,合并title到一个临时表中

INSERT INTO ##Table

EXECUTE [ChineseHoliday].[Helper].[JoinValue]

@TableName = '[pubs].[dbo].[titles]'

,@KeyColName = 'LEFT([title_id], 2)'

,@JoinColName = '''《''+[title] + ''》'''

,@Quote = ','

,@Where = '[type] LIKE ''p%'''

--显示

SELECT * FROM ##Table


--对临时表NewValues的值进行分拆

EXECUTE [ChineseHoliday].[Helper].[SpliteValues]

@TableName = '##Table'

,@KeyColName = '[keyCol]'

,@SpliteColName = '[NewValues]'

,@Quote = ','

--删除临时表

DROP TABLE ##Table

结果:


title_id title

-------- --------------------------------------------------------------------------------

PC1035 But Is It User Friendly?

PC8888 Secrets of Silicon Valley

PC9999 Net Etiquette

PS1372 Computer Phobic AND Non-Phobic Individuals: Behavior Variations

PS2091 Is Anger the Enemy?

PS2106 Life Without Fear

PS3333 Prolonged Data Deprivation: Four Case Studies

PS7777 Emotional Security: A New Algorithm


keyCol NewValues

------ ------------------------------------------

PC 《But Is It User Friendly?》,《Secrets of Silicon Valley》,《Net Etiquette》

PS 《Computer Phobic AND Non-Phobic Individuals: Behavior Variations》,《Is Anger the Enemy?》,《Life Without Fear》,《Prolonged Data Deprivation: Four Case Studies》,《Emotional Security: A New Algorithm》


KeyCol NewValue

------ ------------------------------------------

PC 《But Is It User Friendly?》

PC 《Secrets of Silicon Valley》

PC 《Net Etiquette》

PS 《Computer Phobic AND Non-Phobic Individuals: Behavior Variations》

PS 《Is Anger the Enemy?》

PS 《Life Without Fear》

PS 《Prolonged Data Deprivation: Four Case Studies》

PS 《Emotional Security: A New Algorithm》

继续:字符串的分拆


-- =============================================

-- Author: LzmTW

-- Create date: 20080108

-- Description: 拆分字符串

-- =============================================

CREATE FUNCTION [Func].[Splite]

(

@Input nvarchar(max)

,@Quote nvarchar(max)

)

RETURNS

@Table TABLE

(

[ID] int identity(1,1) PRIMARY KEY

,[Value] nvarchar(max)

)

AS

BEGIN

INSERT @Table

SELECT

[Value] = NewValue

FROM

(

SELECT

SpliteCol = CONVERT(

xml

,N'' + REPLACE(

@Input

,@Quote

,N'') + N'')

) a

OUTER APPLY

(

SELECT NewValue = N.v.value(N'.', 'nvarchar(max)')

FROM SpliteCol.nodes(N'/root/v') N(v)

) b


RETURN

END

示例:


定义新行,


CREATE FUNCTION [Const].[NewLine]

(

)

RETURNS nchar(2)

AS

BEGIN


DECLARE @Result nchar(2)


SELECT @Result = char(13) + char(10)


RETURN @Result

END

 

DECLARE

@Input nvarchar(max)

,@Quote nvarchar(max)


SET @Input = N'90

10

20

30

40

50

60'


SET @Quote = [Const].NewLine()


SELECT * FROM [Func].[Splite] (@Input, @Quote)

结果


ID Value

----------- ------

1 90

2 10

3 20

4 30

5 40

6 50

7 60


(7 行受影响)