related.py 文件源码

def _check_unique(self, **kwargs):
        return [
            checks.Warning(
                'Setting unique=True on a ForeignKey has the same effect as using a OneToOneField.',
                hint='ForeignKey(unique=True) is usually better served by a OneToOneField.',
                obj=self,
                id='fields.W342',
            )
        ] if self.unique else []