擅长:python、mysql、java
<p>以下是文档中的相关部分:<a href="https://docs.djangoproject.com/en/dev/topics/db/managers/#modifying-initial-manager-querysets" rel="nofollow">"If you use custom ^{<cd1>} objects, take note that the first ^{<cd1>} Django encounters (in the order in which they're defined in the model) has a special status. Django interprets the first ^{<cd1>} defined in a class as the "default" ^{<cd1>}, and several parts of Django (including ^{<cd5>}) will use that ^{<cd1>} exclusively for that model. As a result, it's a good idea to be careful in your choice of default manager in order to avoid a situation where overriding ^{<cd7>} results in an inability to retrieve objects you'd like to work with"</a>。在</p>
<p>如果您看一下<a href="https://code.djangoproject.com/browser/django/trunk/django/shortcuts/__init__.py#L87" rel="nofollow">the way ^{<cd8>} is implemented</a>,它们使用模型的<code>_default_manager</code>属性,这就是Django如何引用遇到的第一个管理器。(据我所知,所有Django内部结构都是这样工作的,它们从不使用<code>Model.objects</code>等,因为您不应该假设默认的管理器恰好被称为<code>objects</code>)。在</p>