select rel_id, rel_type, object_id_one
from acs_rels
where object_id_two = :from_user_id
and object_id_one not in (select object_id_one
from acs_rels
where object_id_two = :to_user_id )
select rel_id, rel_type, object_id_one
from acs_rels
where object_id_two = :user_id