""" Regression tests for proper working of ForeignKey(null=True). """ from django.db import models class SystemDetails(models.Model): details = models.TextField() class SystemInfo(models.Model): system_details = models.ForeignKey(SystemDetails, models.CASCADE) system_name = models.CharField(max_length=32) class Forum(models.Model): system_info = models.ForeignKey(SystemInfo, models.CASCADE) forum_name = models.CharField(max_length=32) class Post(models.Model): forum = models.ForeignKey(Forum, models.SET_NULL, null=True) title = models.CharField(max_length=32) def __str__(self): return self.title class Comment(models.Model): post = models.ForeignKey(Post, models.SET_NULL, null=True) comment_text = models.CharField(max_length=250) class Meta: ordering = ('comment_text',) # Ticket 15823 class Item(models.Model): title = models.CharField(max_length=100) class PropertyValue(models.Model): label = models.CharField(max_length=100) class Property(models.Model): item = models.ForeignKey(Item, models.CASCADE, related_name='props') key = models.CharField(max_length=100) value = models.ForeignKey(PropertyValue, models.SET_NULL, null=True)