所以我有这个模型
class ThreadManager(models.Manager):
def by_user(self, user):
qlookup = Q(first=user) | Q(second=user)
qlookup2 = Q(first=user) & Q(second=user)
qs = self.get_queryset().filter(qlookup).exclude(qlookup2).distinct()
return qs
def get_or_new(self, user, other_username): # get_or_create
username = user.username
if username == other_username:
return None
qlookup1 = Q(first__username=username) & Q(second__username=other_username)
qlookup2 = Q(first__username=other_username) & Q(second__username=username)
qs = self.get_queryset().filter(qlookup1 | qlookup2).distinct()
if qs.count() == 1:
return qs.first(), False
elif qs.count() > 1:
return qs.order_by('timestamp').first(), False
else:
Klass = user.__class__
user2 = Klass.objects.get(username=other_username)
if user != user2:
obj = self.model(
first=user,
second=user2
)
obj.save()
return obj, True
return None, False
class Thread(models.Model):
first = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE, related_name='chat_thread_first')
second = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE, related_name='chat_thread_second')
updated = models.DateTimeField(auto_now=True)
timestamp = models.DateTimeField(auto_now_add=True)
thread_notification = models.IntegerField(default=0)
objects = ThreadManager()
在我的模型线程中,我希望得到对象线程的通知,所以我的视图如下
def new_notification_thread(request):
thread_notifier = Thread.objects.filter(pk=1)
thread_notifier.thread_notification += 1
thread_notifier.save()
return JsonResponse(serializers.serialize('json', [thread_notifier]), safe=False)
问题是当我运行代码时
Thread matching query does not exist.
有人知道发生了什么事吗
出现此错误是因为与id=1关联的项目不存在/已删除。因此,当您尝试访问不存在的项目时,会显示错误。尝试访问现有id,您应该可以继续
好的,不要使用
filter
方法来避免F()表达式。而是执行以下操作:它不会给你查询集,所以你可以直接访问所有属性。 下面是:
但当项目超过1个时,必须使用筛选方法。
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