Django ForeignKey中的循环依赖关系？ [英] Circular dependency in Django ForeignKey?

问题描述

我在Django中有两个模型：

I have two models in Django:

A:
  b = ForeignKey("B")

B:
  a = ForeignKey(A)

我想要这些ForeignKey是非NULL。

I want these ForeignKeys to be non-NULL.

但是，我无法创建对象，因为在我保存（）之前它们没有主键。但是如果没有其他对象PrimaryKey，我将无法保存。

However, I cannot create the objects because they don't have a PrimaryKey until I save(). But I cannot save without having the other objects PrimaryKey.

如何创建相互引用的A和B对象？
如果可能的话，我不想允许NULL。

How can I create an A and B object that refer to each other? I don't want to permit NULL if possible.

推荐答案

如果这确实是自举问题，而不是什么在正常使用期间会再次发生，您只需创建一个固定装置，即可使用一些初始数据来预先填充数据库。夹具处理代码包括数据库层的解决方法，以解决前向引用问题。

If this is really a bootstrapping problem and not something that will reoccur during normal usage, you could just create a fixture that will prepopulate your database with some initial data. The fixture-handling code includes workarounds at the database layer to resolve the forward-reference issue.

如果这不是自举问题，您将需要定期在新对象之间创建这些循环关系，您可能应该重新考虑您的架构-外键之一可能是不必要的。

If it's not a bootstrapping problem, and you're going to want to regularly create these circular relations among new objects, you should probably either reconsider your schema--one of the foreign keys is probably unnecessary.

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