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37 lines
1004 B
Python
37 lines
1004 B
Python
"""
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20. Multiple many-to-many relationships between the same two tables
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In this example, an ``Article`` can have many "primary" ``Category`` objects
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and many "secondary" ``Category`` objects.
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Set ``related_name`` to designate what the reverse relationship is called.
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"""
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from django.db import models
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from django.utils.encoding import python_2_unicode_compatible
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@python_2_unicode_compatible
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class Category(models.Model):
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name = models.CharField(max_length=20)
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class Meta:
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ordering = ('name',)
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def __str__(self):
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return self.name
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@python_2_unicode_compatible
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class Article(models.Model):
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headline = models.CharField(max_length=50)
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pub_date = models.DateTimeField()
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primary_categories = models.ManyToManyField(Category, related_name='primary_article_set')
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secondary_categories = models.ManyToManyField(Category, related_name='secondary_article_set')
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class Meta:
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ordering = ('pub_date',)
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def __str__(self):
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return self.headline
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