获取所有相关的 Django 模型对象 [英] Get all related Django model objects

问题描述

如何获取具有指向对象的 ForeignKey 的所有模型对象的列表?(类似于 DELETE CASCADE 之前 Django 管理中的删除确认页面).

How can I get a list of all the model objects that have a ForeignKey pointing to an object? (Something like the delete confirmation page in the Django admin before DELETE CASCADE).

我正在尝试提出一种合并数据库中重复对象的通用方法.基本上，我希望将 ForeignKeys 指向对象B"的所有对象更新为指向对象A"，这样我就可以删除B"而不会丢失任何重要的东西.

I'm trying to come up with a generic way of merging duplicate objects in the database. Basically I want all of the objects that have ForeignKeys points to object "B" to be updated to point to object "A" so I can then delete "B" without losing anything important.

感谢您的帮助！

推荐答案

Django <= 1.7

这为您提供了所有相关对象的属性名称:

Django <= 1.7

This gives you the property names for all related objects:

links = [rel.get_accessor_name() for rel in a._meta.get_all_related_objects()]

然后你可以使用这样的东西来获取所有相关的对象:

You can then use something like this to get all related objects:

for link in links:
    objects = getattr(a, link).all()
    for object in objects:
        # do something with related object instance

我花了一段时间试图弄清楚这一点，所以我可以在上面实现一种观察者模式"我的模型之一.希望有帮助.

I spent a while trying to figure this out so I could implement a kind of "Observer Pattern" on one of my models. Hope it's helpful.

使用_meta.get_fields():https://docs.djangoproject.com/en/1.10/ref/models/meta/#django.db.models.options.Options.get_fields(见反向在 _get_fields() 源代码中)

Use _meta.get_fields(): https://docs.djangoproject.com/en/1.10/ref/models/meta/#django.db.models.options.Options.get_fields (see reverse in the _get_fields() source also)

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