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mirror of https://github.com/django/django.git synced 2024-12-22 17:16:24 +00:00
django/tests/select_related_regress/tests.py
Nick Pope 847f46e9bf
Removed redundant QuerySet.all() calls in docs and tests.
Most QuerySet methods are mapped onto the Manager and, in general,
it isn't necessary to call .all() on the manager.
2022-02-22 10:29:38 +01:00

258 lines
9.6 KiB
Python

from django.test import TestCase
from .models import (
A,
B,
Building,
C,
Chick,
Child,
Class,
Client,
ClientStatus,
Connection,
Country,
Device,
Enrollment,
Hen,
Item,
Organizer,
Person,
Port,
SpecialClient,
State,
Student,
TUser,
)
class SelectRelatedRegressTests(TestCase):
def test_regression_7110(self):
"""
Regression test for bug #7110.
When using select_related(), we must query the
Device and Building tables using two different aliases (each) in order to
differentiate the start and end Connection fields. The net result is that
both the "connections = ..." queries here should give the same results
without pulling in more than the absolute minimum number of tables
(history has shown that it's easy to make a mistake in the implementation
and include some unnecessary bonus joins).
"""
b = Building.objects.create(name="101")
dev1 = Device.objects.create(name="router", building=b)
dev2 = Device.objects.create(name="switch", building=b)
dev3 = Device.objects.create(name="server", building=b)
port1 = Port.objects.create(port_number="4", device=dev1)
port2 = Port.objects.create(port_number="7", device=dev2)
port3 = Port.objects.create(port_number="1", device=dev3)
c1 = Connection.objects.create(start=port1, end=port2)
c2 = Connection.objects.create(start=port2, end=port3)
connections = Connection.objects.filter(
start__device__building=b, end__device__building=b
).order_by("id")
self.assertEqual(
[(c.id, str(c.start), str(c.end)) for c in connections],
[(c1.id, "router/4", "switch/7"), (c2.id, "switch/7", "server/1")],
)
connections = (
Connection.objects.filter(
start__device__building=b, end__device__building=b
)
.select_related()
.order_by("id")
)
self.assertEqual(
[(c.id, str(c.start), str(c.end)) for c in connections],
[(c1.id, "router/4", "switch/7"), (c2.id, "switch/7", "server/1")],
)
# This final query should only have seven tables (port, device and building
# twice each, plus connection once). Thus, 6 joins plus the FROM table.
self.assertEqual(str(connections.query).count(" JOIN "), 6)
def test_regression_8106(self):
"""
Regression test for bug #8106.
Same sort of problem as the previous test, but this time there are
more extra tables to pull in as part of the select_related() and some
of them could potentially clash (so need to be kept separate).
"""
us = TUser.objects.create(name="std")
usp = Person.objects.create(user=us)
uo = TUser.objects.create(name="org")
uop = Person.objects.create(user=uo)
s = Student.objects.create(person=usp)
o = Organizer.objects.create(person=uop)
c = Class.objects.create(org=o)
Enrollment.objects.create(std=s, cls=c)
e_related = Enrollment.objects.select_related()[0]
self.assertEqual(e_related.std.person.user.name, "std")
self.assertEqual(e_related.cls.org.person.user.name, "org")
def test_regression_8036(self):
"""
Regression test for bug #8036
the first related model in the tests below
("state") is empty and we try to select the more remotely related
state__country. The regression here was not skipping the empty column results
for country before getting status.
"""
Country.objects.create(name="Australia")
active = ClientStatus.objects.create(name="active")
client = Client.objects.create(name="client", status=active)
self.assertEqual(client.status, active)
self.assertEqual(Client.objects.select_related()[0].status, active)
self.assertEqual(Client.objects.select_related("state")[0].status, active)
self.assertEqual(
Client.objects.select_related("state", "status")[0].status, active
)
self.assertEqual(
Client.objects.select_related("state__country")[0].status, active
)
self.assertEqual(
Client.objects.select_related("state__country", "status")[0].status, active
)
self.assertEqual(Client.objects.select_related("status")[0].status, active)
def test_multi_table_inheritance(self):
"""Exercising select_related() with multi-table model inheritance."""
c1 = Child.objects.create(name="child1", value=42)
i1 = Item.objects.create(name="item1", child=c1)
i2 = Item.objects.create(name="item2")
self.assertSequenceEqual(
Item.objects.select_related("child").order_by("name"),
[i1, i2],
)
def test_regression_12851(self):
"""
Regression for #12851
Deferred fields are used correctly if you select_related a subset
of fields.
"""
australia = Country.objects.create(name="Australia")
active = ClientStatus.objects.create(name="active")
wa = State.objects.create(name="Western Australia", country=australia)
Client.objects.create(name="Brian Burke", state=wa, status=active)
burke = (
Client.objects.select_related("state")
.defer("state__name")
.get(name="Brian Burke")
)
self.assertEqual(burke.name, "Brian Burke")
self.assertEqual(burke.state.name, "Western Australia")
# Still works if we're dealing with an inherited class
SpecialClient.objects.create(
name="Troy Buswell", state=wa, status=active, value=42
)
troy = (
SpecialClient.objects.select_related("state")
.defer("state__name")
.get(name="Troy Buswell")
)
self.assertEqual(troy.name, "Troy Buswell")
self.assertEqual(troy.value, 42)
self.assertEqual(troy.state.name, "Western Australia")
# Still works if we defer an attribute on the inherited class
troy = (
SpecialClient.objects.select_related("state")
.defer("value", "state__name")
.get(name="Troy Buswell")
)
self.assertEqual(troy.name, "Troy Buswell")
self.assertEqual(troy.value, 42)
self.assertEqual(troy.state.name, "Western Australia")
# Also works if you use only, rather than defer
troy = (
SpecialClient.objects.select_related("state")
.only("name", "state")
.get(name="Troy Buswell")
)
self.assertEqual(troy.name, "Troy Buswell")
self.assertEqual(troy.value, 42)
self.assertEqual(troy.state.name, "Western Australia")
def test_null_join_promotion(self):
australia = Country.objects.create(name="Australia")
active = ClientStatus.objects.create(name="active")
wa = State.objects.create(name="Western Australia", country=australia)
bob = Client.objects.create(name="Bob", status=active)
jack = Client.objects.create(name="Jack", status=active, state=wa)
qs = Client.objects.filter(state=wa).select_related("state")
with self.assertNumQueries(1):
self.assertEqual(list(qs), [jack])
self.assertEqual(qs[0].state, wa)
# The select_related join wasn't promoted as there was already an
# existing (even if trimmed) inner join to state.
self.assertNotIn("LEFT OUTER", str(qs.query))
qs = Client.objects.select_related("state").order_by("name")
with self.assertNumQueries(1):
self.assertEqual(list(qs), [bob, jack])
self.assertIs(qs[0].state, None)
self.assertEqual(qs[1].state, wa)
# The select_related join was promoted as there is already an
# existing join.
self.assertIn("LEFT OUTER", str(qs.query))
def test_regression_19870(self):
hen = Hen.objects.create(name="Hen")
Chick.objects.create(name="Chick", mother=hen)
self.assertEqual(Chick.objects.all()[0].mother.name, "Hen")
self.assertEqual(Chick.objects.select_related()[0].mother.name, "Hen")
def test_regression_10733(self):
a = A.objects.create(name="a", lots_of_text="lots_of_text_a", a_field="a_field")
b = B.objects.create(name="b", lots_of_text="lots_of_text_b", b_field="b_field")
c = C.objects.create(
name="c", lots_of_text="lots_of_text_c", is_published=True, c_a=a, c_b=b
)
results = C.objects.only(
"name",
"lots_of_text",
"c_a",
"c_b",
"c_b__lots_of_text",
"c_a__name",
"c_b__name",
).select_related()
self.assertSequenceEqual(results, [c])
with self.assertNumQueries(0):
qs_c = results[0]
self.assertEqual(qs_c.name, "c")
self.assertEqual(qs_c.lots_of_text, "lots_of_text_c")
self.assertEqual(qs_c.c_b.lots_of_text, "lots_of_text_b")
self.assertEqual(qs_c.c_a.name, "a")
self.assertEqual(qs_c.c_b.name, "b")
def test_regression_22508(self):
building = Building.objects.create(name="101")
device = Device.objects.create(name="router", building=building)
Port.objects.create(port_number="1", device=device)
device = Device.objects.get()
port = device.port_set.select_related("device__building").get()
with self.assertNumQueries(0):
port.device.building