title: Laravel Update or Create Relationships
body: <p>I have an Item model, that has ItemTranslations, I'm receive a Request with the Item I'm updating and the translations for that Item.</p>
  
  <p>Now some of those translations will already be in the database (they have their own id), and some of them will be new. Is there a clean way to go about this?</p>
  
  <p><strong>In pseudo: Update the Item with this request, for each Translations you find in this request, update the translation relation if it exists, else create it for this Item.</strong></p>
  
  <p>This is the layout of my Item.</p>
  
  <pre><code>class Item extends Model
  {
      protected $fillable = ['menu_id', 'parent_id', 'title', 'order', 'resource_link', 'html_class', 'is_blank'];
  
      public function translations()
      {
          return $this-&gt;hasMany(MenuItemTranslation::class, 'menu_item_id');
      }
  }
  </code></pre>
  
  <p>This is the ItemTranslation</p>
  
  <pre><code>class ItemTranslation extends Model
  {
      protected $table = 'item_translations';
      protected $fillable = ['menu_item_id', 'locale', 'name', 'order', 'description', 'link', 'is_online'];
  }
  </code></pre>