Got it 🙂

First we need a table function which returns all integers between x and y (the function is stolen from somewhere, don't remember where...):

create function [dbo].[f_table_numbers] (@st bigint, @end bigint)

returns table

as

return

with

a as (select convert(bigint,0) as n union all select 0),

b as (select 0 as n from a as a cross join a as b),

c as (select 0 as n from b as a cross join b as b),

d as (select 0 as n from c as a cross join c as b),

e as (select 0 as n from d as a cross join d as b),

f as (select 0 as n from e as a cross join e as b),

nums as (select row_number() over (order by (select 1)) as num from f as a cross join f as b)

select @st + num - 1 as num

from nums

where num <= @end-@st+1

Then my table function:

create function Temp (@Id int, @N int)

returns @t table (Id int)

as

begin

insert into @t (Id)

select x.Id

from (select @Id Id) x cross join (select Num from dbo.f_table_numbers(1, @N)) y

return

end

Test:

declare @t1 table (Id int)

insert into @t1 (Id)

select 1 union select 2 union select 3

declare @t2 table (Id int, X int)

insert into @t2 (Id, X)

select 1, 10 union

select 2, 5 union

select 3, 0

;with temp as (

select t1.Id, t2.X

from @t1 t1 join @t2 t2 on (t1.Id = t2.Id)

)

select t1.Id

from temp t1 cross apply dbo.Temp(t1.Id, t1.X)

Edit - talking to my self, sorry, if this is agains some rules you can delete the topic...