'array', 'rating_labels' => 'array', 'is_required' => 'boolean', 'sort_order' => 'integer', ]; } public function questionnaireSet() { return $this->belongsTo(QuestionnaireSet::class); } public function parent() { return $this->belongsTo(QuestionnaireQuestion::class, 'parent_id'); } public function children() { return $this->hasMany(QuestionnaireQuestion::class, 'parent_id')->orderBy('sort_order'); } public function answers() { return $this->hasMany(QuestionnaireAnswer::class); } }