from django.db import models


class Continent(models.Model):


    name =  models.CharField(max_length=255, unique=True)
    code =  models.CharField(max_length=255, unique=True, primary_key = False)
    class Meta:
        ordering = ['name']


class Country(models.Model):

    name = models.CharField(max_length=255, unique=True)
    capital = models.CharField(max_length=255, unique=True)
    code =  models.CharField(max_length=255, unique=True, primary_key = False)
    population = models.PositiveIntegerField(default = 0)
    area = models.PositiveIntegerField(default = 0)
    continent = models.ForeignKey('Continent', related_name = 'countries')
    class Meta:
        ordering = ['name']