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from django.db import models
class Entity(models.Model):
pass
class Country(Entity):
name = models.CharField(max_length=30)
class EUCountry(Country):
join_date = models.DateField()
class City(models.Model):
name = models.CharField(max_length=30)
country = models.ForeignKey(Country, models.CASCADE)
class EUCity(models.Model):
name = models.CharField(max_length=30)
country = models.ForeignKey(EUCountry, models.CASCADE)
class CountryProxy(Country):
class Meta:
proxy = True
class CountryProxyProxy(CountryProxy):
class Meta:
proxy = True
class CityCountryProxy(models.Model):
country = models.ForeignKey(CountryProxyProxy, models.CASCADE)
class Person(models.Model):
name = models.CharField(max_length=30)
born = models.ForeignKey(City, models.CASCADE, related_name='+')
died = models.ForeignKey(City, models.CASCADE, related_name='+')
class PersonProfile(models.Model):
person = models.OneToOneField(Person, models.CASCADE, related_name='profile')
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