лобовое решение не претендую на оригинальность:
речь идёт о SQL Server 2000

--создаю таблицу для теста
if exists(select * from sysobjects where name='Tbl')
drop table Tbl
go
create table Tbl(
id int not null,
value int not null)
go
-- тестовые данные
insert into Tbl([id],[value]) values(9,8)
insert into Tbl([id],[value]) values(9,3)
insert into Tbl([id],[value]) values(8,3)
insert into Tbl([id],[value]) values(9,6)
insert into Tbl([id],[value]) values(9,3)
insert into Tbl([id],[value]) values(5,9)
insert into Tbl([id],[value]) values(5,3)
insert into Tbl([id],[value]) values(4,8)
insert into Tbl([id],[value]) values(3,3)
insert into Tbl([id],[value]) values(3,9)
insert into Tbl([id],[value]) values(7,7)
insert into Tbl([id],[value]) values(6,5)
insert into Tbl([id],[value]) values(6,7)
insert into Tbl([id],[value]) values(6,9)
insert into Tbl([id],[value]) values(8,6)
insert into Tbl([id],[value]) values(6,7)
insert into Tbl([id],[value]) values(2,4)
insert into Tbl([id],[value]) values(7,7)
insert into Tbl([id],[value]) values(7,3)
go
if exists(select * from sysobjects where name='Mul')
drop function Mul
go
-- функция для получения произведения значений с заданным id
create function Mul(@id int)
returns int
as
begin

declare @res int
declare @id_fetch int
select @res=1

declare tlb_cursor cursor FORWARD_ONLY READ_ONLY
for select [value] from Tbl where id=@id

open tlb_cursor
fetch next from tlb_cursor into @id

while @@FETCH_STATUS=0
begin
select @res=@res*@id
fetch next from tlb_cursor into @id
end
close tlb_cursor
deallocate tlb_cursor
return (@res)
end
go
-- проверяем, вуаля :)
select distinct [id], dbo.Mul([id])
from Tbl