Django开发OpenAI聊天机器人时出现Field 'id'类型错误求助

问题 #

开发OpenAI聊天机器人时，实现用户聊天记录保存功能触发TypeError，提示Field 'id' expected a number but got <SimpleLazyObject: <django.contrib.auth.models.AnonymousUser object at 0x0000025FE3733310>>，报错出现在chats = Chat.objects.filter(user=request.user)代码行。

报错堆栈 #

Traceback (most recent call last):
  File "C:\Users\Nathan A\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\db\models\fields\__init__.py", line 2053, in get_prep_value       
    return int(value)
           ^^^^^^^^^^
TypeError: int() argument must be a string, a bytes-like object or a real number, not 'SimpleLazyObject'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "C:\Users\Nathan A\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\core\handlers\exception.py", line 55, in inner
    response = get_response(request)
               ^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Nathan A\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\core\handlers\base.py", line 197, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Nathan A\Downloads\finalproject\finalproject\django_chatbot\chatbot\views.py", line 29, in chatbot
    chats = Chat.objects.filter(user=request.user)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Nathan A\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\db\models\manager.py", line 87, in manager_method
    return getattr(self.get_queryset(), name)(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Nathan A\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\db\models\query.py", line 1436, in filter
    return self._filter_or_exclude(False, args, kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Nathan A\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\db\models\query.py", line 1454, in _filter_or_exclude
    clone._filter_or_exclude_inplace(negate, args, kwargs)
  File "C:\Users\Nathan A\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\db\models\query.py", line 1461, in _filter_or_exclude_inplace     
    self._query.add_q(Q(*args, **kwargs))
  File "C:\Users\Nathan A\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\db\models\sql\query.py", line 1534, in add_q
    clause, _ = self._add_q(q_object, self.used_aliases)
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Nathan A\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\db\models\sql\query.py", line 1565, in _add_q
    child_clause, needed_inner = self.build_filter(
                                 ^^^^^^^^^^^^^^^^^^
  File "C:\Users\Nathan A\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\db\models\sql\query.py", line 1480, in build_filter
    condition = self.build_lookup(lookups, col, value)
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Nathan A\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\db\models\sql\query.py", line 1307, in build_lookup
    lookup = lookup_class(lhs, rhs)
             ^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Nathan A\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\db\models\lookups.py", line 27, in __init__
    self.rhs = self.get_prep_lookup()
               ^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Nathan A\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\db\models\fields\related_lookups.py", line 166, in get_prep_lookup    self.rhs = target_field.get_prep_value(self.rhs)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Nathan A\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\db\models\fields\__init__.py", line 2055, in get_prep_value       
    raise e.__class__(
TypeError: Field 'id' expected a number but got <SimpleLazyObject: <django.contrib.auth.models.AnonymousUser object at 0x0000025FE3733310>>.

视图代码 #

def chatbot(request):
    chats = Chat.objects.filter(user=request.user)

    if request.method == 'POST':
        message = request.POST.get('message')
        response = ask_openai(message)

        chat = Chat(user=request.user, message=message, response=response, created_at=timezone.now())
        chat.save()
        return JsonResponse({'message': message, 'response': response})
    return render(request, 'index.html', {'chats': chats})

原因分析 #

错误根源是当前请求的用户是匿名用户（AnonymousUser）：

• Django中，未登录用户的request.user是由SimpleLazyObject包装的AnonymousUser对象，该对象没有有效的数字类型id；
• Chat模型的user字段是关联到User模型的外键，查询或创建时需要对应存在的用户id（数字类型），因此传入匿名用户对象会触发类型错误。

解决方案 #

方案1：强制用户登录后访问视图 #

使用Django内置的login_required装饰器，确保只有已认证用户才能访问该视图，未登录用户会被重定向到登录页面。

修改视图代码：

from django.contrib.auth.decorators import login_required

@login_required
def chatbot(request):
    chats = Chat.objects.filter(user=request.user)

    if request.method == 'POST':
        message = request.POST.get('message')
        response = ask_openai(message)

        chat = Chat(user=request.user, message=message, response=response, created_at=timezone.now())
        chat.save()
        return JsonResponse({'message': message, 'response': response})
    return render(request, 'index.html', {'chats': chats})

方案2：支持匿名用户存储聊天记录（可选） #

如果需要允许匿名用户使用功能，需调整Chat模型和视图逻辑：

1. 修改Chat模型，允许user字段为空：

from django.db import models
from django.contrib.auth.models import User

class Chat(models.Model):
    user = models.ForeignKey(User, on_delete=models.SET_NULL, null=True, blank=True)
    session_key = models.CharField(max_length=40, blank=True)  # 用session标识匿名用户
    message = models.TextField()
    response = models.TextField()
    created_at = models.DateTimeField(auto_now_add=True)

2. 调整视图代码，区分登录用户和匿名用户：

def chatbot(request):
    # 过滤聊天记录：登录用户用user，匿名用户用session_key
    if request.user.is_authenticated:
        chats = Chat.objects.filter(user=request.user)
    else:
        # 确保session已创建
        if not request.session.session_key:
            request.session.create()
        chats = Chat.objects.filter(session_key=request.session.session_key)

    if request.method == 'POST':
        message = request.POST.get('message')
        response = ask_openai(message)

        # 创建聊天记录
        chat_data = {
            'message': message,
            'response': response
        }
        if request.user.is_authenticated:
            chat_data['user'] = request.user
        else:
            if not request.session.session_key:
                request.session.create()
            chat_data['session_key'] = request.session.session_key

        chat = Chat.objects.create(**chat_data)
        return JsonResponse({'message': message, 'response': response})
    return render(request, 'index.html', {'chats': chats})

内容的提问来源于stack exchange，提问作者Memetendo64