mirror of https://github.com/django/django.git
56 lines
1.7 KiB
Python
56 lines
1.7 KiB
Python
"""
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Regression tests for proper working of ForeignKey(null=True).
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"""
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from django.db import models
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class SystemInfo(models.Model):
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system_name = models.CharField(max_length=32)
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class Forum(models.Model):
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system_info = models.ForeignKey(SystemInfo)
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forum_name = models.CharField(max_length=32)
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class Post(models.Model):
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forum = models.ForeignKey(Forum, null=True)
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title = models.CharField(max_length=32)
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def __unicode__(self):
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return self.title
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class Comment(models.Model):
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post = models.ForeignKey(Post, null=True)
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comment_text = models.CharField(max_length=250)
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def __unicode__(self):
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return self.comment_text
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__test__ = {'API_TESTS':"""
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>>> s = SystemInfo.objects.create(system_name='First forum')
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>>> f = Forum.objects.create(system_info=s, forum_name='First forum')
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>>> p = Post.objects.create(forum=f, title='First Post')
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>>> c1 = Comment.objects.create(post=p, comment_text='My first comment')
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>>> c2 = Comment.objects.create(comment_text='My second comment')
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# Starting from comment, make sure that a .select_related(...) with a specified
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# set of fields will properly LEFT JOIN multiple levels of NULLs (and the things
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# that come after the NULLs, or else data that should exist won't). Regression
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# test for #7369.
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>>> c = Comment.objects.select_related().get(id=1)
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>>> c.post
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<Post: First Post>
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>>> c = Comment.objects.select_related().get(id=2)
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>>> print c.post
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None
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>>> comments = Comment.objects.select_related('post__forum__system_info').all()
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>>> [(c.id, c.comment_text, c.post) for c in comments]
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[(1, u'My first comment', <Post: First Post>), (2, u'My second comment', None)]
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# Regression test for #7530, #7716.
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>>> Comment.objects.select_related('post').filter(post__isnull=True)[0].post is None
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True
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"""}
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