set ANSI_NULLS ON
set QUOTED_IDENTIFIER ON
GO
ALTER function [dbo].[f_Region](@refno varchar)
returns varchar(200)
as
begin
declare @a varchar(200)
set @a=''
select @a=@a+','+ name
from table where refer = @refno
set @a = stuff(@a,1,1,'')
return @a
end
select dbo.f_region('aaa')结果为NULL
但是:
declare @a varchar(200)
set @a=''
select @a=@a+','+ name
from table where refer = @refno
set @a = stuff(@a,1,1,'')
select @a
结果正确.