Django，匹配查询不存在

  • Z时代
  • 2024-01-10
  • 分类：问答

我是Django的新手。当我在pycharm运行命令python manage.py runserver，我得到这样Django，匹配查询不存在

2017-12-03 05:09:56,952 - INFO - server - Listening on endpoint 
tcp:port=8000:interface=127.0.0.1 
Internal Server Error:/
Traceback (most recent call last): 
File "/Users/mac/anaconda/lib/python3.6/site-packages/django/core/handlers/exception.py", line 41, in innerresponse = get_response(request) 
File "/Users/mac/anaconda/lib/python3.6/site-packages/django/core/handlers/base.py", line 187, in _get_response response = self.process_exception_by_middleware(e, request) 
File "/Users/mac/anaconda/lib/python3.6/site-packages/channels/handler.py", line 243, in process_exception_by_middleware 
return super(AsgiHandler,self).process_exception_by_middleware(exception, request) 
File "/Users/mac/anaconda/lib/python3.6/site-packages/django/core/handlers/base.py", line 185, in _get_response response = wrapped_callback(request, *callback_args, **callback_kwargs) 
File "/Users/mac/PycharmProjects/590/flightmate/webapp/views.py", line 180, in index airlines = RecordSet.objects.get(name="airline") 
File "/Users/mac/anaconda/lib/python3.6/site-packages/django/db/models/manager.py", line 85, in manager_method 
return getattr(self.get_queryset(), name)(*args, **kwargs) 
File "/Users/mac/anaconda/lib/python3.6/site-packages/django/db/models/query.py", line 380, in get self.model._meta.object_name 
webapp.models.DoesNotExist: RecordSet matching query does not exist.

错误消息的models.py的代码是：

from __future__ import unicode_literals 
import uuid 
import datetime 
from django.db import models 
class RecordSet(models.Model): 
name = models.CharField(max_length=512) 
value = models.TextField() 
def __unicode__(self): 
    return "{0}: {1}".format(self.name, self.value)

和models.py的父目录的目录webapp。任何建议表示赞赏，谢谢！

回答：

正如你可以回溯看到，这个问题是这样的：

airlines = RecordSet.objects.get(name="airline")

您检索单个对象与get()并且由于它不存在，它返回DoesNotExist例外。这也是Django文档在小节Retrieving a single object with get()

明确提到如果没有结果匹配查询，获得（）将引发 DoesNotExist例外。此例外是正在执行查询的 类的一个属性 - 因此在上面的代码中，如果 没有主键为1的Entry对象，则Django将引发 Entry.DoesNotExist。

要么使用filter()或get()与try ... except声明。如果您知道只有一个对象与您的查询匹配，则应该使用get()，否则使用filter()。

以上是 Django，匹配查询不存在 的全部内容， 来源链接： utcz.com/qa/259584.html

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