Detailing fungsi semua modul dari bugs error

app/Models/Exam.php

@@ -2,20 +2,28 @@
 
 namespace App\Models;
 
+use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Model;
-use Illuminate\Database\Eloquent\Relations\HasMany;
 
 class Exam extends Model
 {
+    use HasFactory;
+
     protected $fillable = [
-        'old_id', 
         'title', 
-        'duration', 
-        'passing_percentage'
+        'description', 
+        'training_type', 
+        'subject_id', 
+        'duration_minutes', 
+        'passing_grade', 
+        'max_retakes', 
+        'is_random_order', 
+        'is_active'
     ];
 
-    public function results(): HasMany
+    // Relasi: Setiap Ujian pasti milik satu Materi (Subject)
+    public function subject()
     {
-        return $this->hasMany(ExamResult::class);
+        return $this->belongsTo(Subject::class);
     }
 }