如何建模以下关系:
class Country(models.Model):
# The capital city of this country
capital = models.ForeignKey(City)
## other country stuff
class City(models.Model):
# The country where this city lies in
country = models.ForeignKey(Country)
## other city stuff
这显然不能编译。(城市在国家的定义中未定义)。有什么建议么?