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d5c7f9efc3
Databases with update_can_self_select = False (MySQL for example) generated non-necessary queries when saving a multitable inherited model, and when the save resulted in update.
296 lines
11 KiB
Python
296 lines
11 KiB
Python
from __future__ import absolute_import
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from operator import attrgetter
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from django.core.exceptions import FieldError
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from django.test import TestCase
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from .models import (Chef, CommonInfo, ItalianRestaurant, ParkingLot, Place,
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Post, Restaurant, Student, StudentWorker, Supplier, Worker, MixinModel)
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class ModelInheritanceTests(TestCase):
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def test_abstract(self):
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# The Student and Worker models both have 'name' and 'age' fields on
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# them and inherit the __unicode__() method, just as with normal Python
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# subclassing. This is useful if you want to factor out common
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# information for programming purposes, but still completely
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# independent separate models at the database level.
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w1 = Worker.objects.create(name="Fred", age=35, job="Quarry worker")
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w2 = Worker.objects.create(name="Barney", age=34, job="Quarry worker")
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s = Student.objects.create(name="Pebbles", age=5, school_class="1B")
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self.assertEqual(unicode(w1), "Worker Fred")
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self.assertEqual(unicode(s), "Student Pebbles")
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# The children inherit the Meta class of their parents (if they don't
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# specify their own).
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self.assertQuerysetEqual(
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Worker.objects.values("name"), [
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{"name": "Barney"},
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{"name": "Fred"},
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],
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lambda o: o
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)
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# Since Student does not subclass CommonInfo's Meta, it has the effect
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# of completely overriding it. So ordering by name doesn't take place
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# for Students.
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self.assertEqual(Student._meta.ordering, [])
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# However, the CommonInfo class cannot be used as a normal model (it
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# doesn't exist as a model).
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self.assertRaises(AttributeError, lambda: CommonInfo.objects.all())
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# A StudentWorker which does not exist is both a Student and Worker
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# which does not exist.
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self.assertRaises(Student.DoesNotExist,
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StudentWorker.objects.get, pk=12321321
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)
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self.assertRaises(Worker.DoesNotExist,
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StudentWorker.objects.get, pk=12321321
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)
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# MultipleObjectsReturned is also inherited.
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# This is written out "long form", rather than using __init__/create()
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# because of a bug with diamond inheritance (#10808)
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sw1 = StudentWorker()
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sw1.name = "Wilma"
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sw1.age = 35
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sw1.save()
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sw2 = StudentWorker()
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sw2.name = "Betty"
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sw2.age = 24
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sw2.save()
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self.assertRaises(Student.MultipleObjectsReturned,
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StudentWorker.objects.get, pk__lt=sw2.pk + 100
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)
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self.assertRaises(Worker.MultipleObjectsReturned,
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StudentWorker.objects.get, pk__lt=sw2.pk + 100
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)
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def test_multiple_table(self):
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post = Post.objects.create(title="Lorem Ipsum")
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# The Post model has distinct accessors for the Comment and Link models.
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post.attached_comment_set.create(content="Save $ on V1agr@", is_spam=True)
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post.attached_link_set.create(
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content="The Web framework for perfections with deadlines.",
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url="http://www.djangoproject.com/"
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)
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# The Post model doesn't have an attribute called
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# 'attached_%(class)s_set'.
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self.assertRaises(AttributeError,
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getattr, post, "attached_%(class)s_set"
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)
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# The Place/Restaurant/ItalianRestaurant models all exist as
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# independent models. However, the subclasses also have transparent
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# access to the fields of their ancestors.
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# Create a couple of Places.
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p1 = Place.objects.create(name="Master Shakes", address="666 W. Jersey")
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p2 = Place.objects.create(name="Ace Harware", address="1013 N. Ashland")
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# Test constructor for Restaurant.
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r = Restaurant.objects.create(
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name="Demon Dogs",
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address="944 W. Fullerton",
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serves_hot_dogs=True,
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serves_pizza=False,
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rating=2
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)
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# Test the constructor for ItalianRestaurant.
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c = Chef.objects.create(name="Albert")
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ir = ItalianRestaurant.objects.create(
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name="Ristorante Miron",
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address="1234 W. Ash",
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serves_hot_dogs=False,
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serves_pizza=False,
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serves_gnocchi=True,
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rating=4,
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chef=c
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)
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self.assertQuerysetEqual(
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ItalianRestaurant.objects.filter(address="1234 W. Ash"), [
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"Ristorante Miron",
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],
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attrgetter("name")
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)
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ir.address = "1234 W. Elm"
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ir.save()
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self.assertQuerysetEqual(
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ItalianRestaurant.objects.filter(address="1234 W. Elm"), [
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"Ristorante Miron",
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],
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attrgetter("name")
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)
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# Make sure Restaurant and ItalianRestaurant have the right fields in
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# the right order.
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self.assertEqual(
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[f.name for f in Restaurant._meta.fields],
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["id", "name", "address", "place_ptr", "rating", "serves_hot_dogs", "serves_pizza", "chef"]
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)
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self.assertEqual(
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[f.name for f in ItalianRestaurant._meta.fields],
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["id", "name", "address", "place_ptr", "rating", "serves_hot_dogs", "serves_pizza", "chef", "restaurant_ptr", "serves_gnocchi"],
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)
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self.assertEqual(Restaurant._meta.ordering, ["-rating"])
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# Even though p.supplier for a Place 'p' (a parent of a Supplier), a
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# Restaurant object cannot access that reverse relation, since it's not
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# part of the Place-Supplier Hierarchy.
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self.assertQuerysetEqual(Place.objects.filter(supplier__name="foo"), [])
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self.assertRaises(FieldError,
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Restaurant.objects.filter, supplier__name="foo"
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)
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# Parent fields can be used directly in filters on the child model.
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self.assertQuerysetEqual(
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Restaurant.objects.filter(name="Demon Dogs"), [
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"Demon Dogs",
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],
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attrgetter("name")
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)
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self.assertQuerysetEqual(
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ItalianRestaurant.objects.filter(address="1234 W. Elm"), [
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"Ristorante Miron",
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],
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attrgetter("name")
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)
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# Filters against the parent model return objects of the parent's type.
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p = Place.objects.get(name="Demon Dogs")
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self.assertIs(type(p), Place)
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# Since the parent and child are linked by an automatically created
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# OneToOneField, you can get from the parent to the child by using the
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# child's name.
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self.assertEqual(
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p.restaurant, Restaurant.objects.get(name="Demon Dogs")
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)
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self.assertEqual(
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Place.objects.get(name="Ristorante Miron").restaurant.italianrestaurant,
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ItalianRestaurant.objects.get(name="Ristorante Miron")
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)
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self.assertEqual(
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Restaurant.objects.get(name="Ristorante Miron").italianrestaurant,
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ItalianRestaurant.objects.get(name="Ristorante Miron")
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)
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# This won't work because the Demon Dogs restaurant is not an Italian
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# restaurant.
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self.assertRaises(ItalianRestaurant.DoesNotExist,
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lambda: p.restaurant.italianrestaurant
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)
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# An ItalianRestaurant which does not exist is also a Place which does
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# not exist.
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self.assertRaises(Place.DoesNotExist,
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ItalianRestaurant.objects.get, name="The Noodle Void"
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)
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# MultipleObjectsReturned is also inherited.
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self.assertRaises(Place.MultipleObjectsReturned,
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Restaurant.objects.get, id__lt=12321
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)
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# Related objects work just as they normally do.
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s1 = Supplier.objects.create(name="Joe's Chickens", address="123 Sesame St")
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s1.customers = [r, ir]
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s2 = Supplier.objects.create(name="Luigi's Pasta", address="456 Sesame St")
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s2.customers = [ir]
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# This won't work because the Place we select is not a Restaurant (it's
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# a Supplier).
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p = Place.objects.get(name="Joe's Chickens")
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self.assertRaises(Restaurant.DoesNotExist,
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lambda: p.restaurant
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)
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self.assertEqual(p.supplier, s1)
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self.assertQuerysetEqual(
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ir.provider.order_by("-name"), [
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"Luigi's Pasta",
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"Joe's Chickens"
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],
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attrgetter("name")
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)
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self.assertQuerysetEqual(
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Restaurant.objects.filter(provider__name__contains="Chickens"), [
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"Ristorante Miron",
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"Demon Dogs",
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],
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attrgetter("name")
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)
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self.assertQuerysetEqual(
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ItalianRestaurant.objects.filter(provider__name__contains="Chickens"), [
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"Ristorante Miron",
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],
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attrgetter("name"),
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)
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park1 = ParkingLot.objects.create(
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name="Main St", address="111 Main St", main_site=s1
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)
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park2 = ParkingLot.objects.create(
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name="Well Lit", address="124 Sesame St", main_site=ir
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)
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self.assertEqual(
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Restaurant.objects.get(lot__name="Well Lit").name,
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"Ristorante Miron"
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)
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# The update() command can update fields in parent and child classes at
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# once (although it executed multiple SQL queries to do so).
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rows = Restaurant.objects.filter(
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serves_hot_dogs=True, name__contains="D"
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).update(
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name="Demon Puppies", serves_hot_dogs=False
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)
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self.assertEqual(rows, 1)
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r1 = Restaurant.objects.get(pk=r.pk)
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self.assertFalse(r1.serves_hot_dogs)
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self.assertEqual(r1.name, "Demon Puppies")
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# The values() command also works on fields from parent models.
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self.assertQuerysetEqual(
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ItalianRestaurant.objects.values("name", "rating"), [
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{"rating": 4, "name": "Ristorante Miron"}
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],
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lambda o: o
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)
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# select_related works with fields from the parent object as if they
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# were a normal part of the model.
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self.assertNumQueries(2,
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lambda: ItalianRestaurant.objects.all()[0].chef
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)
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self.assertNumQueries(1,
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lambda: ItalianRestaurant.objects.select_related("chef")[0].chef
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)
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def test_mixin_init(self):
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m = MixinModel()
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self.assertEqual(m.other_attr, 1)
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def test_update_query_counts(self):
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"""
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Test that update queries do not generate non-necessary queries.
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Refs #18304.
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"""
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c = Chef.objects.create(name="Albert")
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ir = ItalianRestaurant.objects.create(
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name="Ristorante Miron",
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address="1234 W. Ash",
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serves_hot_dogs=False,
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serves_pizza=False,
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serves_gnocchi=True,
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rating=4,
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chef=c
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)
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with self.assertNumQueries(6):
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ir.save()
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