recursion - TSQL A problem with categories tree -

i have problem recursive cte query

let's have category tree (category table)

in cte query, search children of 1 category: (that query works fine)

    mq     (         select c.id parent, c.id child              dbo.category c              c.id = 1               union                 select q.child, c.id                 mq q                     inner join dbo.category c on q.child = c.idparentcategory     ) 

the output

then, want category id, wchih doesn't have child: categories 9,10,12,14,15

with mq     (         select c.id parent, c.id child          dbo.category c          c.id = 1             union                 select q.child, c.id                 mq q                     inner join dbo.category c on q.child = c.idparentcategory                 child in                  (                     select c1.id                      dbo.category c1                     not exists(select c2.id                                       dbo.category c2                                       c2.id = c1.idparentcategory)                 )      ) 

but output wrong:

why ? ideas helpful !

if separate query cte, ok

declare @tab table (parent int, child int);  insert @tab         select * mq      delete @tab     child  in (         select c1.parent         @tab c1         not exists(select c2.parent @tab c2 c2.parent = c1.child)     ) 

with mq (     select c.id parent, c.id child          dbo.category c          c.id = 1           union             select q.child, c.id             mq q                 inner join dbo.category c on q.child = c.idparentcategory ) select child mq child not in (select parent mq) 

would seem give output want - in fact description of problem took form.