"""

Regression tests for proper working of ForeignKey(null=True). Tests these bugs:

    * #7512: including a nullable foreign key reference in Meta ordering has

unexpected results

"""

from django.db import models

# The first two models represent a very simple null FK ordering case.

class Author(models.Model):

    name = models.CharField(max_length=150)

class Article(models.Model):

    title = models.CharField(max_length=150)

    author = models.ForeignKey(Author, models.SET_NULL, null=True)

    class Meta:

        ordering = ["author__name"]

# These following 4 models represent a far more complex ordering case.

class SystemInfo(models.Model):

    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)

class Comment(models.Model):

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

    comment_text = models.CharField(max_length=250)

    class Meta:

        ordering = ["post__forum__system_info__system_name", "comment_text"]