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HomeDatabaseMysql Tutorialsqlserver中字符串切割函数总结

本文章收藏了大量的在sqlserver中字符串切割函数,包括了自用自定义函数或sql带带的函数来操作,有需要了解的同学可参考一下

实例1
循环while一个个读取

 代码如下 复制代码

ALTER FUNCTION [dbo].[Split]
(   
    @Array VARCHAR(7000)
    ,@Split CHAR(1)
)
RETURNS @T TABLE(v VARCHAR(100))
AS
BEGIN
    WHILE(CHARINDEX(@Split,@Array)0)  
        BEGIN  
          INSERT @T VALUES(SUBSTRING(@Array,1,CHARINDEX(@Split,@Array)-1));
          SET @Array=STUFF(@Array,1,CHARINDEX(@Split,@Array),'');
        END  
      INSERT @T VALUES(@Array);
    RETURN;
END;


实例2

带,号的利用CHARINDEX处理

 代码如下 复制代码

 CREATE FUNCTION dbo.f_str(
@str varchar(8000)
)RETURNS @r TABLE(id int IDENTITY(1, 1), value varchar(5000))
AS
BEGIN
/* Function body */
DECLARE @pos int
SET @pos = CHARINDEX(',', @str)
WHILE @pos > 0
BEGIN
INSERT @r(value) VALUES(LEFT(@str, @pos - 1))
SELECT
@str = STUFF(@str, 1, @pos, ''),
@pos = CHARINDEX(',', @str)
END
IF @str > ''
INSERT @r(value) VALUES(@str)
RETURN

END

select * from f_splitstr('中,国,人')

 

实例3

按指定符号分割字符串,返回分割后的元素个数,方法很简单,就是看字符串中存在多少个分隔符号,然后再加一,就是要求的结果。

 代码如下 复制代码

CREATE Get_StrArrayLength
(
  @str varchar(1024),  --要分割的字符串
  @split varchar(10)  --分隔符号
)
returns int
as
begin
  declare @location int
  declare @start int
  declare @length int

  set @str=ltrim(rtrim(@str))
  set @location=charindex(@split,@str)
  set @length=1
  while @location0
  begin
    set @start=@location+1
    set @location=charindex(@split,@str,@start)
    set @length=@length+1
  end
  return @length
end
调用示例:select dbo.Get_StrArrayLength('78,1,2,3',',')
返回值:4


 

实例4

按指定符号分割字符串,返回分割后指定索引的第几个元素,象数组一样方便

 代码如下 复制代码

CREATE function Get_StrArrayStrOfIndex
(
  @str varchar(1024),  --要分割的字符串
  @split varchar(10),  --分隔符号
  @index int --取第几个元素
)
returns varchar(1024)
as
begin
  declare @location int
  declare @start int
  declare @next int
  declare @seed int

  set @str=ltrim(rtrim(@str))
  set @start=1
  set @next=1
  set @seed=len(@split)
 
  set @location=charindex(@split,@str)
  while @location0 and @index>@next
  begin
    set @start=@location+@seed
    set @location=charindex(@split,@str,@start)
    set @next=@next+1
  end
  if @location =0 select @location =len(@str)+1
 --这儿存在两种情况:1、字符串不存在分隔符号 2、字符串中存在分隔符号,跳出while循环后,@location为0,那默认为字符串后边有一个分隔符号。
 
  return substring(@str,@start,@location-@start)
end

调用示例:select dbo.Get_StrArrayStrOfIndex('8,9,4',',',2)
返回值:9


SQLServer中的字符串截取函数

1.截取已知长度的函数

A.截取从字符串左边开始N个字符 Declare @S1 varchar(100)

 代码如下 复制代码
Select @S1='http://www.111cn.net'
Select Left(@S1,4)


------------------------------------
显示结果: http


B.截取从字符串右边开始N个字符(例如取字符www.111cn.net) Declare @S1 varchar(100)

 代码如下 复制代码
Select @S1='http://www.111cn.net'
Select right(@S1,11)


------------------------------------
显示结果: www.111cn.net


C.截取字符串中任意位置及长度(例如取字符www) Declare @S1 varchar(100)

 代码如下 复制代码
Select @S1='http://www.111cn.net'
Select SUBSTRING(@S1,8,3)

------------------------------------
显示结果: www.111cn.net


以上例子皆是已知截取位置及长度,下面介绍未知位置的例子

2.截取未知位置的函数

A.截取指定字符串后的字符串(例如截取http://后面的字符串)


方法一: Declare @S1 varchar(100)

 代码如下 复制代码
Select @S1='http://www.111cn.net'
Select Substring(@S1,CHARINDEX('www',@S1)+1,Len(@S1))
/*此处也可以这样写:Select Substring(@S1,CHARINDEX('//',@S1)+2,Len(@S1))*/

------------------------------------
显示结果: www.111cn.net


需要注意:CHARINDEX函数搜索字符串时,不区分大小写,因此CHARINDEX('www',@S1)也可以写成CHARINDEX('WWW',@S1)

 

方法二:(与方法一类似) Declare @S1 varchar(100)

 代码如下 复制代码
Select @S1='http://www.111cn.net'
Select Substring(@S1,PATINDEX('%www%',@S1)+1,Len(@S1))
--此处也可以这样写:Select Substring(@S1,PATINDEX('%//%',@S1)+2,Len(@S1))


------------------------------------
显示结果: www.111cn.net 函数PATINDEX与CHARINDEX区别在于:前者可以参数一些参数,增加查询的功能


方法三: Declare @S1 varchar(100)

 代码如下 复制代码
Select @S1='http://www.111cn.net'
Select REPLACE(@S1,'http://','')


------------------------------------
显示结果: www.111cn.net

利用字符替换函数REPLACE,将除需要显示字符串外的字符替换为空


方法四:

 代码如下 复制代码
Declare @S1 varchar(100)
Select @S1='http://www.111cn.net'
Select STUFF(@S1,CHARINDEX('http://',@S1),Len('http://'),'')

本文章后面的实例就是上面函数的分解一,一个个stuff,substring等这些函数的组合就可以完美的实现字符串分切了哦。

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