如何在Laravel 5.2中正确设置透视表的雄辩关系

Question

I have three tables in a db which are as follows (not all of the columns but minimised for clarity):

admins (id, community_id, email, password, level)
community (community_id, community_name)
community_results (community_result_id, community_session_id)
community_sessions (community_session_id, community_id)

I have setup the associated models and within my admin controller I have the following code that simply grabs all the results in the database into a laravel collection (and this works fine). The admin table contains two types of admin user - one is the 'superuser' that has access to every single row in the db, and the other type is a 'community admin' and will only have access to their community results (defined by the level column in the admins table).

When logged into the admin as a 'community admin' I want to only get results for their community (admins.community_id is the foreign key in this instance that relates this admin to a community).

eg John Doe is a 'community admin' for the 'ACME Community' and belongs to the community_id 5, when logged in he will only get 'community results' for all of the 'community sessions' that relate to that particular community (community_id is the foreign key in the community_sessions table).

So i'd need to find a way to create a modified version of the results() relation within the CommunitySession.php model but rather than query EVERY row only retrieve those of one or more community_session_id's - alternatively is there way using the Community.php model to create a relation to basically pull in results using the relation like the following...

$community = Community::find(5);
$community->results; // pull results for this community using a relation

Can anyone suggest the best way to do this? Thanks in advance

class AdminResultController extends Controller
{
   public function index()
   {
      // if logged in as the 'superuser' admin get ALL results
      if (Auth::guard('admin')->user()->level == 1) 
      {
         $results = CommunityResult::all();
      } else {
        // logged in as 'standard' admin get only their community results
        $results = new CommunityResult;
        // how do I get collection of results for this community only
      }
   }
}

// CommunityResult.php (model)

class CommunityResult extends Model
{
  public $primaryKey = 'community_result_id';

  public function session()
  {
    return $this->hasOne('App\CommunitySession', 'community_session_id', 'community_session_id');
  }
}

// CommunitySession.php (model)

class CommunitySession extends Model
{
  public $primaryKey = 'community_session_id';

  public function community()
  {
    return $this->belongsTo('App\Community', 'community_id');
  }

  public function results()
  {
    return $this->hasMany('App\CommunityResult', 'community_session_id');
  }  
}

// Community.php (model)

class Community extends Model
{
  public $table = 'community';
  public $primaryKey = 'community_id';

  public function sessions()
  {
    return $this->hasMany('App\CommunitySession', 'community_id');
  }
}

Answer 1

Auth::guard('admin')->user()->with('sessions.results')