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5643a3b51b
This prevents silent data loss. Thanks Aymeric Augustin for the initial patch and Loic Bistuer for the review.
64 lines
1.6 KiB
Python
64 lines
1.6 KiB
Python
"""
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10. One-to-one relationships
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To define a one-to-one relationship, use ``OneToOneField()``.
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In this example, a ``Place`` optionally can be a ``Restaurant``.
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"""
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from __future__ import unicode_literals
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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 Place(models.Model):
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name = models.CharField(max_length=50)
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address = models.CharField(max_length=80)
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def __str__(self):
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return "%s the place" % self.name
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@python_2_unicode_compatible
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class Restaurant(models.Model):
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place = models.OneToOneField(Place, primary_key=True)
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serves_hot_dogs = models.BooleanField(default=False)
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serves_pizza = models.BooleanField(default=False)
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def __str__(self):
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return "%s the restaurant" % self.place.name
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class Bar(models.Model):
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place = models.OneToOneField(Place, null=True)
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@python_2_unicode_compatible
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class Waiter(models.Model):
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restaurant = models.ForeignKey(Restaurant)
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name = models.CharField(max_length=50)
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def __str__(self):
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return "%s the waiter at %s" % (self.name, self.restaurant)
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class ManualPrimaryKey(models.Model):
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primary_key = models.CharField(max_length=10, primary_key=True)
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name = models.CharField(max_length=50)
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class RelatedModel(models.Model):
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link = models.OneToOneField(ManualPrimaryKey)
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name = models.CharField(max_length=50)
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@python_2_unicode_compatible
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class MultiModel(models.Model):
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link1 = models.OneToOneField(Place)
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link2 = models.OneToOneField(ManualPrimaryKey)
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name = models.CharField(max_length=50)
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def __str__(self):
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return "Multimodel %s" % self.name
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