如何在 Django 会话模型中设置自定义字段？

Question

我已经根据this 延长了 Django 中的会话。总之，我添加了一个名为account_id 的字段来保存会话所属用户的用户ID。

一切正常，除了我添加的自定义字段account_id 没有在登录时设置。这样做：

from django.contrib import auth
from MyApp.models import CustomSession

def login(request):
    username = request.POST['username']
    password = request.POST['password']
    user = auth.authenticate(username=username, password=password)
    if user is not None:
        try:
            auth.login(request, user)
            session_key = request.session.session_key
            # CODE HERE
            if session_key is not None:
                return HttpResponse(json.dumps({'status': 'Success'}))
            else:
                return HttpResponse(json.dumps({'status': 'Fail'}))

我已尝试将以下内容发送到CODE HERE。但是，它们都不起作用：

1. request.session.model.account_id = user.id

2. session = CustomSession.objects.get(pk=session_key)
   session.account_id = user.id
   session.modified = True
   

3. request.session.account_id = user.id
4. request.session[account_id] = user.id

在每次尝试中，account_id 在数据库中都是NULL。

我在这里错过了什么？

Answer 1

您错过了 CustomSession 是一个模型的事实；您需要保存实例，而不是像在版本 2 中那样对其设置“修改”。

session = CustomSession.objects.get(pk=session_key)
session.account_id = user.id
session.save()

Answer 2

如果您想在会话表中提供自定义名称或创建自定义字段，您可以按照以下步骤操作。

定义自定义会话后端：

my_project
    my_project/
        settings.py
        session_backend.py
        ...
    user/
        models.py
        ...

from django.contrib.sessions.backends.db import SessionStore as DBStore
import user


class SessionStore(DBStore):

    @classmethod
    def get_model_class(cls):
        return user.models.MySession

    def create_model_instance(self, data):
        """
        overriding the function to save the changes to db using `session["user_id"] = user.id` .
        This will create the model instance with the custom field values. 
        When you add more field to the custom session model you have to update the function 
        to handle those fields as well.
        """
        obj = super().create_model_instance(data)
        try:
            user_id = data.get('user_id')
        except (ValueError, TypeError):
            user_id = None

        obj.user_id = user_id
        return obj

然后在settings.py 中导入您的自定义类

SESSION_ENGINE = "my_project.session_backend"

在应用程序的models.py 中定义自定义模型，例如user

from django.contrib.sessions.models import Session


class MySession(Session):
    # you can also add custom field if required like this user column which can be the FK to the user table 
    user = models.ForeignKey('user', on_delete=models.CASCADE) 

    class Meta:
        app_label = "user"
        db_table = "my_session"

现在运行以下命令进行迁移

python manage.py makemigrations
python manage.py migrate

完成:)