Query forced before every single update?

Hello

This is my first intervention in this forum, I'm trying to create my first project on phalcon. I just can't update a relation after the first saving, at least if I don't query the same object again.

My relationships...

For Bands class.

$this->hasMany('id', '\App\Models\Songs', 'band_id', ['alias' => 'Songs']);

For Songs class.

$this->belongsTo('band_id', '\App\Models\Bands', 'id', [
    'alias' => 'Band'
]);

This doesn't works for me

$band1 = new Bands();
$band1->name = 'Band 1';
$band1->save();

$song1 = new Songs();
$song1->band = $band1;
$song1->name = 'Song 1';
$song1->save();

$band2 = new Bands();
$band2->name = 'Band 2';
$band2->save();

$song1->band = $band2;
$song1->update();

I get this error message...

'Record cannot be updated because it does not exist'

The same if I try this way...

$song1 = Songs::find(['id' => $song1->id]);
$song1->band = $band2;
$song1->update();

The only way that I can make it work is this...

$song1 = Songs::find(['id' => $song1->id]);
$song1->band = $band2;
$song1->save();

So, my questions are...

1. Update is just for non-relationships properties?
2. Is not possible to modify objects references to relationships once defined without querying again?
3. How can I add double lines using markdown in this editor =) ?