Count active items/year without a temporary year table - sql

Question

With the following record structure:
<item> | <start> | <stop>
Item-A | 2013-04-05 | 2014-06-07
Item-B | 2012-06-07 | 2015-03-07
Is it possible to query using SQL (in MS-SQL >=2008 and Firebird >= 2.5) how many items are active per year? The result should be:
2012 | 1
2013 | 2
2014 | 2
2015 | 1
I've used a temorary table containing series (1900..2100) and join the origin table and temporary table using BETWEEN and extract(year..). But I'm searching for a better solution without using an extra table.

Answer 1

This meets your requirement.
select Years.[Year],
count(1) [Count]
from MyTable mt
join (select distinct(year(start)) as [Year]
from MyTable
union
select distinct(year(stop))
from MyTable
union
select year(getdate())
from MyTable
where exists
(select 1
from MyTable
where stop is null)) as Years
on Years.[Year] between Year(mt.start) and Year(isnull(mt.stop, getdate()))
group by Years.[Year]
order by Years.[Year]

Answer 2

This is how I would do it using a helper function.
declare #StartMin datetime
declare #StopMax datetime
select #StartMin = min(start),
#StopMax = max(isnull(stop, getdate()))
from MyTable
select Years.[Year],
count(1) [Count]
from MyTable mt
join [dbo].[YearsBetween](#StartMin, #StopMax) as Years
on Years.[Year] between Year(mt.start) and Year(isnull(mt.stop, getdate()))
group by Years.[Year]
order by Years.[Year]
This is the helper function, I have a lot of them, DatesBetween, MonthsBetween, NumbersBetween, etc.
create function [dbo].[YearsBetween](#Start datetime, #Stop datetime)
returns #Years TABLE
(
[Year] int
)
begin
declare #StartYear int
declare #StopYear int
set #StartYear = year(#Start)
set #StopYear = year(#Stop)
while(#StartYear <= #StopYear)
begin
insert into #Years
values(#StartYear)
set #StartYear = #StartYear + 1
end
return;
end