Question

In Django I have theses models:

class Artist(models.Model):
    name = models.CharField(max_length=128)
    born_place = models.ForeignKey(???)
    dead_place = models.ForeignKey(???)
    live_places = models.ManyToManyField(???)
    work_places = models.ManyToManyField(???)

class Country(models.Model):
    iso = models.CharField(max_length=2, primary_key=True)
    name = models.CharField(max_length=50)

class Region(models.Model):
    iso = models.CharField(max_length=2, blank=True)
    name = models.CharField(max_length=150)
    country = models.ForeignKey('Country')

class City(models.Model):
    name = models.CharField(max_length=150)
    region = models.ForeignKey('Region')

All the places (born_place, dead_place, live_places, work_places) can be a City or a Region or a Country. And a City should necessarily have a Region, and a Region should necessarily have a Country.

How can I achieve that?

Answer 1

You can also use model inheritance

class Territory(models.Model):
    name = models.CharField(max_length=150)

class Country(Territory):
    iso = models.CharField(max_length=2, primary_key=True)

class Region(Territory):
    iso = models.CharField(max_length=2, blank=True)
    country = models.ForeignKey('Country')

class City(Territory):
    region = models.ForeignKey('Region')

class Artist(models.Model):
    name = models.CharField(max_length=128)
    born_place = models.ForeignKey(Territory)
    dead_place = models.ForeignKey(Territory)
    live_places = models.ManyToManyField(Territory)
    work_places = models.ManyToManyField(Territory)

Best regards!