django源码分析----Related继承结构

在django中关联关系大概可以分成many-to-one(foriegnkey)、one-to-one、many-to-many 这三种、它们有如下的类结构

class RelatedField(Field):
class ForeignObject(RelatedField):
class ForeignKey(ForeignObject):
class OneToOneField(ForeignKey):
class ManyToManyField(RelatedField):

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