select count(*)
from k137.flytt f
left join kod.kodortkod d on f.tilortkod = d.ortkod
where f.tilortnmn != '' and d.ortnmn != f.tilortnmn
  or (d.ortnmn is null and length(f.tilortnmn) > 0)
  or (d.ortnmn is not null and f.tilortnmn is null)