SQL自定义函数split 将数组(分隔字符串)返回阵列(表)
Create FUNCTION [dbo].[SplitToTable] ( @SplitString nvarchar(max), @Separator nvarchar(10)=' ' ) RETURNS @SplitStringsTable TABLE ( [id] int identity(1,1), [value] nvarchar(max) ) AS BEGIN DECLARE @CurrentIndex int; DECLARE @NextIndex int; DECLARE @ReturnText nvarchar(max); SELECT @CurrentIndex=1; WHILE(@CurrentIndex<=len(@SplitString)) BEGIN SELECT @NextIndex=charindex(@Separator,@SplitString,@CurrentIndex); IF(@NextIndex=0 OR @NextIndex IS NULL) SELECT @NextIndex=len(@SplitString)+1; SELECT @ReturnText=substring(@SplitString,@CurrentIndex,@NextIndex-@CurrentIndex); INSERT INTO @SplitStringsTable([value]) VALUES(@ReturnText); SELECT @CurrentIndex=@NextIndex+1; END RETURN; END select * FROm dbo.SplitToTable('111,b2222,323232,32d,e,323232f,g3222', ',')
结果为
id value ----------- ---------------------------------------
1 111
2 b2222
3 323232
4 32d
5 e
6 323232f
7 g3222
(7 行受影响)
使用循环的方法
首先GetSplitLength函数返回分割后的字符数组的长度。
Create function [dbo].[GetSplitLength] ( @String nvarchar(max), --要分割的字符串 @Split nvarchar(10) --分隔符号 ) returns int as begin declare @location int declare @start int declare @length int set @String=ltrim(rtrim(@String)) set @location=charindex(@split,@String) set @length=1 while @location<>0 begin set @start=@location+1 set @location=charindex(@split,@String,@start) set @length=@length+1 end return @length end
select dbo.GetSplitLength('111,b2222,323232,32d,e,323232f,g3222',',')
结果为7。
GetSplitOfIndex函数是按顺序分别获取分割后的字符串。
ALTER function [dbo].[GetSplitOfIndex] ( @String nvarchar(max), --要分割的字符串 @split nvarchar(10), --分隔符号 @index int --取第几个元素 ) returns nvarchar(1024) as begin declare @location int declare @start int declare @next int declare @seed int set @String=ltrim(rtrim(@String)) set @start=1 set @next=1 set @seed=len(@split) set @location=charindex(@split,@String) while @location<>0 and @index>@next begin set @start=@location+@seed set @location=charindex(@split,@String,@start) set @next=@next+1 end if @location =0 select @location =len(@String)+1 return substring(@String,@start,@location-@start) end
select dbo.GetSplitOfIndex('111,b2222,323232,32d,e,323232f,g3222',',', 3)
结果323232。
DECLARE @Tags nvarchar(max); SELECT @Tags='111,b2222,323232,32d,e,323232f,g3222'; DECLARE @Tag nvarchar(1000) DECLARE @next int; set @next=1 DECLARE @Length int; SELECT @Length=dbo.GetSplitLength(@Tags,',') while @next<=@Length begin SET @Tag = left(dbo.GetSplitOfIndex(@Tags,',',@next), 16); print @Tag SET @Next=@Next+1; END
结果为:
111
b2222
323232
32d
e
323232f
g3222