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