使用Djongo连接Django与MongoDB执行makemigrations时出错求助

问题 #

使用 Django 4.1.13 + Djongo 1.3.6 + MongoDB 7.0.3 搭建动态网站，配置数据库连接后执行 python manage.py makemigrations 命令时触发以下错误：

数据库配置（settings.py） #

DATABASES = { 'default': { 'ENGINE': 'djongo', 'NAME': 'Cake_Bakery', 'CLIENT':{'host':'localhost','port':27017} } }

报错信息 #

(cake) PS D:\Cake Eccomerce\cake\Cake_Bakery> python manage.py makemigrations
    System check identified some issues:

    WARNINGS:
    ?: (urls.W002) Your URL pattern '/products' [name='products'] has a route beginning with a '/'.             Remove this slash as it is unnecessary. If this pattern is targeted in an include(), ensure the include() pattern has a trailing '/'.
     No changes detected
    Traceback (most recent call last):
    File "D:\Cake Eccomerce\cake\Cake_Bakery\manage.py", line 22, in <module>
    main()
     File "D:\Cake Eccomerce\cake\Cake_Bakery\manage.py", line 18, in main
    execute_from_command_line(sys.argv)
     File "D:\Cake Eccomerce\cake\Lib\site-packages\django\core\management\__init__.py", line 446,   in execute_from_command_line
    utility.execute()
  File "D:\Cake Eccomerce\cake\Lib\site-packages\django\core\management\__init__.py", line 440, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "D:\Cake Eccomerce\cake\Lib\site-packages\django\core\management\base.py", line 415, in run_from_argv
    connections.close_all()
  File "D:\Cake Eccomerce\cake\Lib\site-packages\django\utils\connection.py", line 85, in close_all
    conn.close()
  File "D:\Cake Eccomerce\cake\Lib\site-packages\django\utils\asyncio.py", line 26, in inner
    return func(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^
  File "D:\Cake Eccomerce\cake\Lib\site-packages\django\db\backends\base\base.py", line 358, in    close
    self._close()
  File "D:\Cake Eccomerce\cake\Lib\site-packages\djongo\base.py", line 208, in _close
    if self.connection:
  File "D:\Cake Eccomerce\cake\Lib\site-packages\pymongo\database.py", line 1337, in __bool__
    raise NotImplementedError(
NotImplementedError: Database objects do not implement truth value testing or bool(). Please compare with None instead: database is not None
(cake) PS D:\Cake Eccomerce\cake\Cake_Bakery>

解决方案 #

错误根源是 Djongo 1.3.6 的代码中直接对 self.connection 做布尔判断，但 MongoDB 7.0.3 配套的 pymongo 版本已不再允许对 Database 对象进行布尔值测试，必须显式与 None 比较。修复步骤如下：

• 找到虚拟环境中 Djongo 的 base.py 文件，路径示例：D:\Cake Eccomerce\cake\Lib\site-packages\djongo\base.py
• 打开文件定位到第 208 行的代码：if self.connection:
• 将该行修改为：if self.connection is not None:
• 保存文件后重新执行 python manage.py makemigrations

额外提示 #

控制台同时抛出了 URL 路由警告，建议同步修复 urls.py 中的路由规则：将以 / 开头的路由（如 '/products'）改为不带开头斜杠的形式（如 'products'），避免后续路由匹配异常。

内容的提问来源于stack exchange，提问作者user19000614