SQL2000 合并行数据

Create table Tab
([Col1] int,[Col2] nvarchar(1))

Insert Tab 
select 1,N'a' 
union all select 1,N'b' 
union all select 1,N'c' 
union all select 2,N'd' 
union all select 2,N'e' 
union all select 3,N'f'

create function F_Str(@Col1 int) 
returns nvarchar(100) 
as
begin 
declare @S nvarchar(100)
select @S=isnull(@S+',','')+Col2 from Tab where Col1=@Col1
return @S 
end

Select distinct Col1,Col2=dbo.F_Str(Col1) from Tab