Here is the snippet of code for the save()
method. You'll see that it eventually calls attach()
.
/**
* Save a new model and attach it to the parent model.
*
* @param \Illuminate\Database\Eloquent\Model $model
* @param array $joining
* @param bool $touch
* @return \Illuminate\Database\Eloquent\Model
*/
public function save(Model $model, array $joining = [], $touch = true)
{
$model->save(['touch' => false]);
$this->attach($model->getKey(), $joining, $touch); ($touch 应该是更新关联表的时间戳)
return $model;
}
One big difference is that it also saves the model that you are passing to it. In other words, you can essentially create a new role (or even update the old one) while also attaching it to the user. For example:
// Get the user
$user = User::first();
// Instantiate a new role
$role = new Role($attributes);
// Creates the role / persists it into the database and attaches this role to the user
$user->roles()->save($role, ['expires' => $expires]);