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"""
Many-to-one relationships
To define a many-to-one relationship, use ``ForeignKey()``.
"""
from __future__ import unicode_literals
from django.db import models
from django.utils.encoding import python_2_unicode_compatible
@python_2_unicode_compatible
class Reporter(models.Model):
first_name = models.CharField(max_length=30)
last_name = models.CharField(max_length=30)
email = models.EmailField()
def __str__(self):
return "%s %s" % (self.first_name, self.last_name)
@python_2_unicode_compatible
class Article(models.Model):
headline = models.CharField(max_length=100)
pub_date = models.DateField()
reporter = models.ForeignKey(Reporter, models.CASCADE)
def __str__(self):
return self.headline
class Meta:
ordering = ('headline',)
# If ticket #1578 ever slips back in, these models will not be able to be
# created (the field names being lower-cased versions of their opposite
# classes is important here).
class First(models.Model):
second = models.IntegerField()
class Second(models.Model):
first = models.ForeignKey(First, models.CASCADE, related_name='the_first')
# Protect against repetition of #1839, #2415 and #2536.
class Third(models.Model):
name = models.CharField(max_length=20)
third = models.ForeignKey('self', models.SET_NULL, null=True, related_name='child_set')
class Parent(models.Model):
name = models.CharField(max_length=20, unique=True)
bestchild = models.ForeignKey('Child', models.SET_NULL, null=True, related_name='favored_by')
class Child(models.Model):
name = models.CharField(max_length=20)
parent = models.ForeignKey(Parent, models.CASCADE)
class ToFieldChild(models.Model):
parent = models.ForeignKey(Parent, models.CASCADE, to_field='name')
# Multiple paths to the same model (#7110, #7125)
@python_2_unicode_compatible
class Category(models.Model):
name = models.CharField(max_length=20)
def __str__(self):
return self.name
class Record(models.Model):
category = models.ForeignKey(Category, models.CASCADE)
@python_2_unicode_compatible
class Relation(models.Model):
left = models.ForeignKey(Record, models.CASCADE, related_name='left_set')
right = models.ForeignKey(Record, models.CASCADE, related_name='right_set')
def __str__(self):
return "%s - %s" % (self.left.category.name, self.right.category.name)
# Test related objects visibility.
class SchoolManager(models.Manager):
def get_queryset(self):
return super(SchoolManager, self).get_queryset().filter(is_public=True)
class School(models.Model):
is_public = models.BooleanField(default=False)
objects = SchoolManager()
class Student(models.Model):
school = models.ForeignKey(School, models.CASCADE)
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