select sum(qty), name
from (
select count(m.owner_id) as qty, o.name
from transport t,owner o,motorbike m
where t.type='motobike' and o.owner_id=m.owner_id
and t.type_id=m.motorbike_id
group by m.owner_id
union all
select count(c.owner_id) as qty, o.name,
from transport t,owner o,car c
where t.type='car' and o.owner_id=c.owner_id and t.type_id=c.car_id
group by c.owner_id
) t
group by name
