def test_students_cached(self, db):
"""students property is cached to avoid redundant queries."""
e = factories.RelationshipFactory.create().elder
with utils.assert_num_queries(1):
list(e.students)
list(e.students)
def test_students_cached(self, db):
"""students property is cached to avoid redundant queries."""
e = factories.RelationshipFactory.create().elder
with utils.assert_num_queries(1):
list(e.students)
list(e.students)
def test_get_user_select_related(db):
"""get_user method returns user with profile pre-selected."""
profile = factories.ProfileFactory.create()
backend = auth_backend.EmailBackend()
user = backend.get_user(profile.user.id)
with utils.assert_num_queries(0):
user.profile
def test_get_user_select_related(db):
"""get_user method returns user with profile pre-selected."""
profile = factories.ProfileFactory.create()
backend = auth_backend.EmailBackend()
user = backend.get_user(profile.user.id)
with utils.assert_num_queries(0):
user.profile
def test_authenticate_select_related(db):
"""authenticate method returns user with profile pre-selected."""
factories.ProfileFactory.create(user__email='*****@*****.**',
user__password='******')
backend = auth_backend.EmailBackend()
user = backend.authenticate(username='******', password='******')
with utils.assert_num_queries(0):
user.profile
def test_authenticate_select_related(db):
"""authenticate method returns user with profile pre-selected."""
factories.ProfileFactory.create(
user__email='*****@*****.**', user__password='******')
backend = auth_backend.EmailBackend()
user = backend.authenticate(username='******', password='******')
with utils.assert_num_queries(0):
user.profile
def test_prefetch_elders(self, db):
"""Can prefetch elders to avoid N queries."""
# A and B demonstrate that relationship lists are ordered by name
r1b = factories.RelationshipFactory.create(from_profile__name='B')
r1a = factories.RelationshipFactory.create(to_profile=r1b.student,
from_profile__name='A')
r2 = factories.RelationshipFactory.create()
# one query for profiles and one for elder relationships
with utils.assert_num_queries(2):
qs = model.Profile.objects.prefetch_elders()
assert set(tuple(p.elders) for p in qs) == {(r1a.elder, r1b.elder),
(r2.elder, ), ()}
def test_prefetch_relationships(self, db):
"""Can prefetch students and elders in a single query."""
r1 = factories.RelationshipFactory.create()
r2 = factories.RelationshipFactory.create()
# one query for profiles and one for relationships
with utils.assert_num_queries(2):
# order_by call demonstrates persistence after a clone
qs = model.Profile.objects.prefetch_relationships().order_by(
'name')
assert set(tuple(p.students) for p in qs) == {(r1.student, ),
(r2.student, ), ()}
assert set(tuple(p.elders) for p in qs) == {(r1.elder, ),
(r2.elder, ), ()}
def test_prefetch_students(self, db):
"""Can prefetch students to avoid N queries."""
# A and B demonstrate that relationship lists are ordered by name
r1b = factories.RelationshipFactory.create(to_profile__name='B')
r1a = factories.RelationshipFactory.create(
from_profile=r1b.elder, to_profile__name='A')
r2 = factories.RelationshipFactory.create()
# one query for profiles and one for student relationships
with utils.assert_num_queries(2):
qs = model.Profile.objects.prefetch_students()
assert set(
tuple(p.students) for p in qs
) == {(r1a.student, r1b.student), (r2.student,), ()}
def test_prefetch_with_already_populated_result_cache(self, db):
"""Can prefetch on an already-populated queryset."""
r1 = factories.RelationshipFactory.create()
r2 = factories.RelationshipFactory.create()
qs = model.Profile.objects.all()
# populate its result cache
len(qs)
# set it to prefetch without triggering a clone
qs._prefetch_elders = True
# just one query for elder relationships
with utils.assert_num_queries(1):
assert set(tuple(p.elders) for p in qs) == {(r1.elder, ),
(r2.elder, ), ()}
def test_prefetch_relationships(self, db):
"""Can prefetch students and elders in a single query."""
r1 = factories.RelationshipFactory.create()
r2 = factories.RelationshipFactory.create()
# one query for profiles and one for relationships
with utils.assert_num_queries(2):
# order_by call demonstrates persistence after a clone
qs = model.Profile.objects.prefetch_relationships().order_by('name')
assert set(
tuple(p.students) for p in qs
) == {(r1.student,), (r2.student,), ()}
assert set(
tuple(p.elders) for p in qs
) == {(r1.elder,), (r2.elder,), ()}
def test_prefetch_with_already_populated_result_cache(self, db):
"""Can prefetch on an already-populated queryset."""
r1 = factories.RelationshipFactory.create()
r2 = factories.RelationshipFactory.create()
qs = model.Profile.objects.all()
# populate its result cache
len(qs)
# set it to prefetch without triggering a clone
qs._prefetch_elders = True
# just one query for elder relationships
with utils.assert_num_queries(1):
assert set(
tuple(p.elders) for p in qs
) == {(r1.elder,), (r2.elder,), ()}
