belongsTo(User::class, 'before_id', 'id'); } public function user() { return $this->belongsTo(config('user_relation.user_model')); } public function parent() { return $this->belongsTo(config('user_relation.user_model'), 'parent_id')->withDefault(); } public function operator() { return $this->belongsTo(Admin::class, 'operator_id')->withDefault(); } }