sql函数实现去除字符串中的相同的字符串

---去除字符串中重?偷闹岛???
create function StringRemove(@str nvarchar(2000))
returns varchar(2000)
as
begin
declare @result nvarchar(2000),@temp nvarchar(1000)
set @result=''
set @temp=''
while(charindex(',',@str)<>0)
begin
set @temp=substring(@str,1,charindex(',',@str))
if(charindex(@temp,@result)<=0)
set @result=@result+@temp
set @str=stuff(@str,1,charindex(',',@str),'')
end
return @result
end
GO
--('?T聚文','?T','?T聚文','1','23','1')

--?y?
select dbo.StringRemove('?T聚文,?T,?T聚文,1,23,1')