from django.contrib.gis.db import models class SimpleModel(models.Model): class Meta: abstract = True class Location(SimpleModel): point = models.PointField() def __str__(self): return self.point.wkt class City(SimpleModel): name = models.CharField(max_length=50) state = models.CharField(max_length=2) location = models.ForeignKey(Location, models.CASCADE) def __str__(self): return self.name class AugmentedLocation(Location): extra_text = models.TextField(blank=True) class DirectoryEntry(SimpleModel): listing_text = models.CharField(max_length=50) location = models.ForeignKey(AugmentedLocation, models.CASCADE) class Parcel(SimpleModel): name = models.CharField(max_length=30) city = models.ForeignKey(City, models.CASCADE) center1 = models.PointField() # Throwing a curveball w/`db_column` here. center2 = models.PointField(srid=2276, db_column='mycenter') border1 = models.PolygonField() border2 = models.PolygonField(srid=2276) def __str__(self): return self.name class Author(SimpleModel): name = models.CharField(max_length=100) dob = models.DateField() class Article(SimpleModel): title = models.CharField(max_length=100) author = models.ForeignKey(Author, models.CASCADE, unique=True) class Book(SimpleModel): title = models.CharField(max_length=100) author = models.ForeignKey(Author, models.SET_NULL, related_name='books', null=True) class Event(SimpleModel): name = models.CharField(max_length=100) when = models.DateTimeField()