Exam Question/Answer 3-way m:n

models/ExamTyperatingAnswer.php

@@ -1,6 +1,7 @@
 <?php namespace GermanAirlinesVa\Schooling\Models;
 
 use Model;
+use Illuminate\Database\Eloquent\Builder;
 
 /**
  * Model
@@ -33,4 +34,29 @@ class ExamTyperatingAnswer extends Model
   public $belongsTo = [
     'exam_question' => ['GermanAirlinesVa\Schooling\Models\ExamTyperatingQuestion', 'key' => 'exam_question_id'],
   ];
+
+  public $belongsToMany = [
+    'exam_typeratings' => [
+      'GermanAirlinesVa\Schooling\Models\ExamTyperating',
+      'table' => 'exam_exam_answer_exam_question',
+      'key' => 'exam_answer_id',
+      'otherKey' => 'exam_id',
+    ],
+  ];
+
+  /**
+   * The "booting" method of the model.
+   *
+   * @return void
+   */
+  protected static function boot()
+  {
+    parent::boot();
+
+    static::addGlobalScope('exam_typerating_answer_typerating_id', function (Builder $builder) {
+      $builder->whereHas('exam_question', function ($query) {
+        $query->where('typerating_id', '<>', null);
+      });
+    });
+  }
 }