有時我們要用到大量操作時都會對字串進行拆分,可是SQL Server中卻沒有內建Split函數,所以要自己來實現了。沒什麼好說的,需要的朋友直接拿去用吧
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
/*
by kudychen 2011-9-28
*/
CREATE function [dbo].[SplitString]
(
@Input nvarchar(max), --input string to be separated
@Separator nvarchar(max)=',', --a string that delimit the substrings in the input string
@RemoveEmptyEntries bit=1 --the return value does not include array elements that contain an empty string
)
returns @TABLE table
(
[Id] int identity(1,1),
[Value] nvarchar(max)
)
as
begin
declare @Index int, @Entry nvarchar(max)
set @Index = charindex(@Separator,@Input)
while (@Index>0)
begin
set @Entry=ltrim(rtrim(substring(@Input, 1, @Index-1)))
if (@RemoveEmptyEntries=0) or (@RemoveEmptyEntries=1 and @Entry<>'')
begin
insert into @TABLE([Value]) Values(@Entry)
end
set @Input = substring(@Input, @Index+datalength(@Separator)/2, len(@Input))
set @Index = charindex(@Separator, @Input)
end
set @Entry=ltrim(rtrim(@Input))
if (@RemoveEmptyEntries=0) or (@RemoveEmptyEntries=1 and @Entry<>'')
begin
insert into @TABLE([Value]) Values(@Entry)
end
return
end
如何使用:
declare @str1 varchar(max), @str2 varchar(max), @str3 varchar(max)
set @str1 = '1,2,3'
set @str2 = '1###2###3'
set @str3 = '1###2###3###'
select [Value] from [dbo].[SplitString](@str1, ',', 1)
select [Value] from [dbo].[SplitString](@str2, '###', 1)
select [Value] from [dbo].[SplitString](@str3, '###', 0)
執行結果:
裡面還有個自增的[Id]欄位哦,在某些情況下有可能會用上的,例如根據Id來儲存排序等等。
例如根據某表的ID儲存排序:
update a set a.[Order]=t.[Id]
from [dbo].[表] as a join [dbo].SplitString('1,2,3', ',', 1) as t on a.[Id]=t.[Value]
具體的應用請根據自己的情況來吧:)