Django：列出模型的所有反向关系 [英] Django: list all reverse relations of a model

问题描述

我想要我的django应用程序提供任何模型的字段的列表（这将有助于GUI构建本身）。

I would like my django application to serve a list of any model's fields (this will help the GUI build itself).

想像一下这个类步骤的所有字段可能位于项目中，我有我的理由:-)）

Imagine the classes (ignore the fact that all field of Steps could be in Item, I have my reasons :-) )

class Item(models.Model):
    name = models.CharField(max_length=100)
    description = models.TextField()

class Steps(models.Model):
    item = models.OneToOneField('Item', related_name='steps')
    design = models.BooleanField(default=False)
    prototype = models.BooleanField(default=False)
    production = models.BooleanField(default=False)

现在，当我想列出一个模型的字段：

Now, when I want to list a model's fields:

def get_fields(model):
    return model._meta.fields + model._meta.many_to_many

但我也想得到相关一对一外键列表到我的模型。在我的情况下， Item.steps 不会在该列表中。

But I would also like to get the list of "related" one-to-one foreign keys to my models. In my case Item.steps would not be in that list.

我发现 model._meta.get_all_field_names 确实包含所有相关的字段。

I have found that model._meta.get_all_field_names does include all the related fields.

但是当我调用 Item._meta.get_field_by_name（'steps'）时，它返回一个持有 RelatedObject ，它不会立即告诉我这是否是一个单一的关系或一对多（我想列出只有一个对 - 一个关系）。

But when I call Item._meta.get_field_by_name('steps') it returns a tuple holding a RelatedObject, which does not tell me instantly whether this is a single relation or a one-to-many (I want to list only reversed one-to-one relations).

此外，我可以使用这一段代码：

Also, I can use this bit of code:

from django.db.models.fields.related import SingleRelatedObjectDescriptor
reversed_f_keys = [attr for attr in Item.__dict__.values() \
                  if isinstance(attr, SingleRelatedObjectDescriptor)]

但我不太满意。

欢迎任何帮助，想法和提示！

Any help, idea, tips are welcome!

干杯

推荐答案

这是改变了（在1.8我认为）和奥利维尔的答案不再工作了。根据 docs ，新的方法是

This was changed (in 1.8 I think) and Olivier's answer doesn't work anymore. According to the docs, the new way is

[f for f in User._meta.get_fields()
    if f.auto_created and not f.concrete]

这包括一对一，一对一和多对多。

This includes one-to-one, many-to-one, and many-to-many.

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