select k.*, v.*, (select distinct Veci_Id, Obrazok from Obrazky_veci) O from Kategoria k, Veci v where v.Kat = k.id and v.id = O.Veci_id
select k.*, v.*, (select distinct Veci_Id, Obrazok from Obrazky_veci) O from Kategoria k, Veci v where v.Kat = k.id and v.id = O.Veci_id