优化根据用户id获取用户名函数

Service/CommonService.py

@@ -192,12 +192,13 @@ class CommonService:
         """
         if userID:
             device_user_qs = Device_User.objects.filter(userID=userID).values('username', 'userEmail', 'phone')
-            if device_user_qs[0]['username']:
-                return device_user_qs[0]['username']
-            elif device_user_qs[0]['userEmail']:
-                return device_user_qs[0]['userEmail']
-            elif device_user_qs[0]['phone']:
-                return device_user_qs[0]['phone']
+            if device_user_qs.exists():
+                if device_user_qs[0]['username']:
+                    return device_user_qs[0]['username']
+                elif device_user_qs[0]['userEmail']:
+                    return device_user_qs[0]['userEmail']
+                elif device_user_qs[0]['phone']:
+                    return device_user_qs[0]['phone']
         return ''
 
     # 生成随机数