1 """

     2 Regression tests for proper working of ForeignKey(null=True).

     3 """

     4 

     5 from django.db import models

     6 

     7 class SystemDetails(models.Model):

     8     details = models.TextField()

     9 

    10 class SystemInfo(models.Model):

    11     system_details = models.ForeignKey(SystemDetails)

    12     system_name = models.CharField(max_length=32)

    13 

    14 class Forum(models.Model):

    15     system_info = models.ForeignKey(SystemInfo)

    16     forum_name = models.CharField(max_length=32)

    17 

    18 class Post(models.Model):

    19     forum = models.ForeignKey(Forum, null=True)

    20     title = models.CharField(max_length=32)

    21 

    22     def __unicode__(self):

    23         return self.title

    24 

    25 class Comment(models.Model):

    26     post = models.ForeignKey(Post, null=True)

    27     comment_text = models.CharField(max_length=250)

    28 

    29     class Meta:

    30         ordering = ('comment_text',)

    31 

    32     def __unicode__(self):

    33         return self.comment_text