Barcode counting over groups

Question

Hi all,
I am working on a barcode for my invoices print. This barcode counts over the invoices from 1 to 16 and then starts over again. For example if i have a set of 6 invoices each of 3 pages the barcode numbering will be as follows:
invoice 1 page 1: 1
invoice 1 page 2: 2
invoice 1 page 3: 3
invoice 2 page 1: 4
invoice 2 page 2: 5
invoice 5 page 3: 15
invoice 6 page 1: 16
invoice 6 page 2: 1
invoice 6 page 3: 2
I have tried to solve this with some xsl-fo programming, but i can't get the page-number or total pages per invoice into a variable. So I can't determine how many pages have been printed for previous invoices and which is the next number to print in the barcode.
Hope you can give me some advice.

Answer 1

Looks like this should return what you are expecting:
--drop table #temp
create table #temp
autoid int,
assembly_no nvarchar(10),
rank_no int
insert into #temp (autoid, assembly_no, rank_no) values (1, 'Assembly1', 2)
insert into #temp (autoid, assembly_no, rank_no) values (2, 'Assembly2', 1)
insert into #temp (autoid, assembly_no, rank_no) values (3, 'Assembly1', 2)
insert into #temp (autoid, assembly_no, rank_no) values (4, 'Assembly1', 1)
insert into #temp (autoid, assembly_no, rank_no) values (5, 'Assembly1', 0)
insert into #temp (autoid, assembly_no, rank_no) values (6, 'Assembly2', 2)
insert into #temp (autoid, assembly_no, rank_no) values (7, 'Assembly2', 1)
select t.assembly_no, count(nullif(t.rank_no, 0))
from #temp t
inner join 
select autoid, rank_no, row_number() over (partition by assembly_no order by autoid desc) as ct
from #temp
)x
on x.autoid = t.autoid
and x.ct <= 2
group by t.assembly_no