Django：为什么在ForeignKey定义中在模型周围使用引号 [英] Django: Why are quotes around the model in a ForeignKey definition

问题描述

我想知道这两个外键定义之间的区别。

I want to know what the difference between these two foreignkey definitions are.

(1) MyFKField = models.ForeignKey('MyModel')
(2) MyFKField = models.ForeignKey(MyModel)

我了解（我认为...）（1） MyModel 需要在同一文件中定义，而另一个需要导入，但是我不确定原因/

I understand (I think...) that (1) MyModel needs to be defined in that same file and the other needs to be imported, but I'm unsure of the reason/benifits of doing it either way.

我浏览了Django文档，但找不到任何东西，我也不知道这是问的正确地方，所以

I had a look through the Django docs but couldnt find anything, and Im also not sure if this is the right place to ask, so apologies if not.

干杯

推荐答案

Django文档指出您要在（1）中使用字符串：

Django docs states that you would use a string to (1):

• 您想要递归关系（例如- model.ForeignKey（'self'））


• 用于引用可能尚未定义的模型（用于循环
  
• 在另一个应用程序中引用模型的快捷方式（例如- model.ForeignKey（'app.mymodel'））

• You want a recursive relationship (eg - model.ForeignKey('self'))
• For referring to a model that is possibly not defined yet (for cyclic relationships).
• A shortcut to refer to a model in another application (eg - model.ForeignKey('app.mymodel'))

但是通常，直接指定模型类很容易知道它来自（2）的位置。

But in general, specifying the model class directly is clear where it's coming from (2).

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