title: Remove one to one relationship in Laravel
body: <p>I'm using Laravel 5.2  and I have created a one to one relation as follows. </p>
  
  <pre><code> $driver    = Driver::find($driver-&gt;id);
   $vehicle = Vehicle::find($vehicleId);
   $vehicle-&gt;driver()-&gt;associate($driver);
   $vehicle-&gt;save();
  </code></pre>
  
  <p>This works perfectly. In some scenarios I need to break this relationship by removing the particular driver from the vehicle.</p>
  
  <pre><code>$driver    = Driver::find($driver-&gt;id);
  $vehicle = Vehicle::find($vehicleId);
  $vehicle-&gt;driver_id-&gt;NULL;
  $vehicle-&gt;save();
  </code></pre>
  
  <p>But this doesn't work. I have tried some other approaches. </p>
  
  <pre><code>$vehicle-&gt;driver()-&gt;delete();
  
  $vehicle-&gt;driver()-&gt;dissociate();
  </code></pre>
  
  <p>Following are the two models.</p>
  
  <pre><code>class Driver extends Model
  {
      public function vehicle()
      {
          return $this-&gt;hasOne(Vehicle::class);
      }
  }
  
  class Vehicle extends Model
  {
      protected $primaryKey = 'vehicle_number';
      public $incrementing = false;
  
      public function driver()
      {
          return $this-&gt;belongsTo(Driver::class);
      }
  }
  </code></pre>
  
  <p>Nothing is working in my case. Could anyone please give a hint, what's wrong in there.</p>