$self->{db}->{offer}->{product_id}->{name} #### (($self->{db} || {})->{offer}||{})->{name} #### $self->{db}->{users}->{ $user_id_1 }->limits->{ $user_id_2 }; #### eval{ $self->{$db}->{users}->{$user_id_1}->limits->{$user_id_2}; };