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113 lines
3.0 KiB
Python
113 lines
3.0 KiB
Python
"""
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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 django.db import models
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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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class Restaurant(models.Model):
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place = models.OneToOneField(Place, models.CASCADE, 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, models.CASCADE)
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serves_cocktails = models.BooleanField(default=True)
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class UndergroundBar(models.Model):
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place = models.OneToOneField(Place, models.SET_NULL, null=True)
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serves_cocktails = models.BooleanField(default=True)
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class Waiter(models.Model):
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restaurant = models.ForeignKey(Restaurant, models.CASCADE)
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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 Favorites(models.Model):
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name = models.CharField(max_length=50)
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restaurants = models.ManyToManyField(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, models.CASCADE)
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name = models.CharField(max_length=50)
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class MultiModel(models.Model):
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link1 = models.OneToOneField(Place, models.CASCADE)
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link2 = models.OneToOneField(ManualPrimaryKey, models.CASCADE)
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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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class Target(models.Model):
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name = models.CharField(max_length=50, unique=True)
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class Pointer(models.Model):
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other = models.OneToOneField(Target, models.CASCADE, primary_key=True)
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class Pointer2(models.Model):
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other = models.OneToOneField(Target, models.CASCADE, related_name="second_pointer")
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class HiddenPointer(models.Model):
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target = models.OneToOneField(Target, models.CASCADE, related_name="hidden+")
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class ToFieldPointer(models.Model):
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target = models.OneToOneField(
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Target, models.CASCADE, to_field="name", primary_key=True
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)
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# Test related objects visibility.
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class SchoolManager(models.Manager):
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def get_queryset(self):
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return super().get_queryset().filter(is_public=True)
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class School(models.Model):
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is_public = models.BooleanField(default=False)
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objects = SchoolManager()
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class DirectorManager(models.Manager):
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def get_queryset(self):
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return super().get_queryset().filter(is_temp=False)
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class Director(models.Model):
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is_temp = models.BooleanField(default=False)
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school = models.OneToOneField(School, models.CASCADE)
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objects = DirectorManager()
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