public function actionLogin()
 {
     $user_name = \Yii::$app->request->post()['user_name'];
     $password = \Yii::$app->request->post()['pwd'];
     $author_info = new Author();
     $author_info->name = $user_name;
     $author_info->pwd = $password;
     if ($author_info->save()) {
         $author_id = Author::findBySql("select id from author ORDER BY id DESC LIMIT 0,1")->asArray()->all();
         $array = ['error_no' => 0, 'error_msg' => '', 'data' => $author_id[0]];
         echo json_encode($array);
     }
 }