Exam Question/Answer 3-way m:n

models/ExamMemberRankQuestion.php

@@ -32,10 +32,36 @@ class ExamMemberRankQuestion extends Model
   ];
 
   public $hasMany = [
-    'exam_answers' => 'GermanAirlinesVa\Schooling\Models\ExamMemberRankAnswer',
+    'exam_answers' => [
+      'GermanAirlinesVa\Schooling\Models\ExamMemberRankAnswer',
+      'key' => 'exam_question_id',
+    ],
   ];
 
   public $belongsTo = [
     'member_rank' => 'GermanAirlinesVa\Schooling\Models\MemberRank',
   ];
+
+  public $belongsToMany = [
+    'exam_member_ranks' => [
+      'GermanAirlinesVa\Schooling\Models\ExamMemberRank',
+      'table' => 'exam_exam_answer_exam_question',
+      'key' => 'exam_question_id',
+      'otherKey' => 'exam_id',
+    ],
+  ];
+
+  /**
+   * The "booting" method of the model.
+   *
+   * @return void
+   */
+  protected static function boot()
+  {
+    parent::boot();
+
+    static::addGlobalScope('exam_member_rank_question_member_rank_id', function ($builder) {
+      $builder->where('member_rank_id', '<>', null);
+    });
+  }
 }