历史遗留的代码问题

service/modules/v1/controllers/StoreController.php

@@ -51,7 +51,7 @@ class StoreController extends BaseServiceController
     {
 
         $post= \Yii::$app->request->post();
-        $search=$post['search'];
+        $search=$post['search']?? '';
         $su_id = DoctorInfo::find()->select('su_id')->where([
             'su_id' => \Yii::$app->user->identity->getId()
         ])->column();