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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
|
