我可以创建将不会持久保存在数据库中的Django模型吗？ [英] Can I create django model, which will be not persisted in database?

问题描述

有问题的情况：
我可以创建将不会持久保存在数据库中的Django模型（models.Model）吗？

As asked in question: Can I create django model(models.Model), which will be not persisted in database?

原因是我想要在我的django管理员中使用它来基于forms.ModelForm

The reason is I want use it in my django admin to build custom form basing on forms.ModelForm

推荐答案

您可以覆盖模型的 save（）方法来防止保存到数据库，并使用 managed = False 来防止Django创建适当的表：

You can override the model's save() method to prevent saving to the database, and use managed = False to prevent Django from creating the appropriate tables:

class NonPersistantModel(models.Model):
    def save(self, *args, **kwargs):
        pass

    class Meta:
        managed = False

当批量操作尝试保存该模型的实例时，这将引发错误，因为将不使用 save 方法，并且该表将不存在。在您的用例中（如果您只想使用模型来构建 ModelForm ），应该没问题。

Note that this will raise an error when a bulk operation tries to save instances of this model, as the save method wouldn't be used and the table wouldn't exist. In your use-case (if you only want to use the model to build a ModelForm) that shouldn't be a problem.

但是，我强烈建议您将表单构建为 forms.Form 的子类。模型是数据库表的抽象，普通形式可以完成生成的 ModelForm 可以做的一切，甚至更多。

However, I would strongly recommend building your form as a subclass of forms.Form. Models are abstractions for your database tables, and plain forms are capable of anything a generated ModelForm can do, and more.

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