Model basic CRUD methods and other queries on other tables using $this->db->table()

There is no data to update" means the model thinks there is no data to update.
If you read the stacktrace and the model code, you can find why there is no data.

I have to transform this

PHP Code:

$this->where('id', (int)$id_sottoevento)
    ->update(
        [
          'data_inizio' => '0000-00-00',
          'data_fine'  => '0000-00-00'
        ]
    ); 


in this

PHP Code:

$this->save(
    [
      'id'          => $id_sottoevento,
      'data_inizio' => '0000-00-00',
      'data_fine'   => '0000-00-00'
    ]
); 


so it works


If instead I want to use update() and not save()

PHP Code:

$this->update(
    $id_sottoevento, 
    [
      'data_inizio' => '0000-00-00',
      'data_fine'  => '0000-00-00'
    ]
); 


I haven't tested this but it should work


But I still don't understand why the first version doesn't work, it will be my limitation