mirror of https://github.com/django/django.git
595 lines
26 KiB
Python
595 lines
26 KiB
Python
import threading
|
|
import time
|
|
from unittest import mock
|
|
|
|
from multiple_database.routers import TestRouter
|
|
|
|
from django.core.exceptions import FieldError
|
|
from django.db import (
|
|
DatabaseError, NotSupportedError, connection, connections, router,
|
|
transaction,
|
|
)
|
|
from django.test import (
|
|
TransactionTestCase, override_settings, skipIfDBFeature,
|
|
skipUnlessDBFeature,
|
|
)
|
|
from django.test.utils import CaptureQueriesContext
|
|
|
|
from .models import (
|
|
City, CityCountryProxy, Country, EUCity, EUCountry, Person, PersonProfile,
|
|
)
|
|
|
|
|
|
class SelectForUpdateTests(TransactionTestCase):
|
|
|
|
available_apps = ['select_for_update']
|
|
|
|
def setUp(self):
|
|
# This is executed in autocommit mode so that code in
|
|
# run_select_for_update can see this data.
|
|
self.country1 = Country.objects.create(name='Belgium')
|
|
self.country2 = Country.objects.create(name='France')
|
|
self.city1 = City.objects.create(name='Liberchies', country=self.country1)
|
|
self.city2 = City.objects.create(name='Samois-sur-Seine', country=self.country2)
|
|
self.person = Person.objects.create(name='Reinhardt', born=self.city1, died=self.city2)
|
|
self.person_profile = PersonProfile.objects.create(person=self.person)
|
|
|
|
# We need another database connection in transaction to test that one
|
|
# connection issuing a SELECT ... FOR UPDATE will block.
|
|
self.new_connection = connection.copy()
|
|
|
|
def tearDown(self):
|
|
try:
|
|
self.end_blocking_transaction()
|
|
except (DatabaseError, AttributeError):
|
|
pass
|
|
self.new_connection.close()
|
|
|
|
def start_blocking_transaction(self):
|
|
self.new_connection.set_autocommit(False)
|
|
# Start a blocking transaction. At some point,
|
|
# end_blocking_transaction() should be called.
|
|
self.cursor = self.new_connection.cursor()
|
|
sql = 'SELECT * FROM %(db_table)s %(for_update)s;' % {
|
|
'db_table': Person._meta.db_table,
|
|
'for_update': self.new_connection.ops.for_update_sql(),
|
|
}
|
|
self.cursor.execute(sql, ())
|
|
self.cursor.fetchone()
|
|
|
|
def end_blocking_transaction(self):
|
|
# Roll back the blocking transaction.
|
|
self.cursor.close()
|
|
self.new_connection.rollback()
|
|
self.new_connection.set_autocommit(True)
|
|
|
|
def has_for_update_sql(self, queries, **kwargs):
|
|
# Examine the SQL that was executed to determine whether it
|
|
# contains the 'SELECT..FOR UPDATE' stanza.
|
|
for_update_sql = connection.ops.for_update_sql(**kwargs)
|
|
return any(for_update_sql in query['sql'] for query in queries)
|
|
|
|
@skipUnlessDBFeature('has_select_for_update')
|
|
def test_for_update_sql_generated(self):
|
|
"""
|
|
The backend's FOR UPDATE variant appears in
|
|
generated SQL when select_for_update is invoked.
|
|
"""
|
|
with transaction.atomic(), CaptureQueriesContext(connection) as ctx:
|
|
list(Person.objects.all().select_for_update())
|
|
self.assertTrue(self.has_for_update_sql(ctx.captured_queries))
|
|
|
|
@skipUnlessDBFeature('has_select_for_update_nowait')
|
|
def test_for_update_sql_generated_nowait(self):
|
|
"""
|
|
The backend's FOR UPDATE NOWAIT variant appears in
|
|
generated SQL when select_for_update is invoked.
|
|
"""
|
|
with transaction.atomic(), CaptureQueriesContext(connection) as ctx:
|
|
list(Person.objects.all().select_for_update(nowait=True))
|
|
self.assertTrue(self.has_for_update_sql(ctx.captured_queries, nowait=True))
|
|
|
|
@skipUnlessDBFeature('has_select_for_update_skip_locked')
|
|
def test_for_update_sql_generated_skip_locked(self):
|
|
"""
|
|
The backend's FOR UPDATE SKIP LOCKED variant appears in
|
|
generated SQL when select_for_update is invoked.
|
|
"""
|
|
with transaction.atomic(), CaptureQueriesContext(connection) as ctx:
|
|
list(Person.objects.all().select_for_update(skip_locked=True))
|
|
self.assertTrue(self.has_for_update_sql(ctx.captured_queries, skip_locked=True))
|
|
|
|
@skipUnlessDBFeature('has_select_for_no_key_update')
|
|
def test_update_sql_generated_no_key(self):
|
|
"""
|
|
The backend's FOR NO KEY UPDATE variant appears in generated SQL when
|
|
select_for_update() is invoked.
|
|
"""
|
|
with transaction.atomic(), CaptureQueriesContext(connection) as ctx:
|
|
list(Person.objects.all().select_for_update(no_key=True))
|
|
self.assertIs(self.has_for_update_sql(ctx.captured_queries, no_key=True), True)
|
|
|
|
@skipUnlessDBFeature('has_select_for_update_of')
|
|
def test_for_update_sql_generated_of(self):
|
|
"""
|
|
The backend's FOR UPDATE OF variant appears in the generated SQL when
|
|
select_for_update() is invoked.
|
|
"""
|
|
with transaction.atomic(), CaptureQueriesContext(connection) as ctx:
|
|
list(Person.objects.select_related(
|
|
'born__country',
|
|
).select_for_update(
|
|
of=('born__country',),
|
|
).select_for_update(
|
|
of=('self', 'born__country')
|
|
))
|
|
features = connections['default'].features
|
|
if features.select_for_update_of_column:
|
|
expected = [
|
|
'select_for_update_person"."id',
|
|
'select_for_update_country"."entity_ptr_id',
|
|
]
|
|
else:
|
|
expected = ['select_for_update_person', 'select_for_update_country']
|
|
expected = [connection.ops.quote_name(value) for value in expected]
|
|
self.assertTrue(self.has_for_update_sql(ctx.captured_queries, of=expected))
|
|
|
|
@skipUnlessDBFeature('has_select_for_update_of')
|
|
def test_for_update_sql_model_inheritance_generated_of(self):
|
|
with transaction.atomic(), CaptureQueriesContext(connection) as ctx:
|
|
list(EUCountry.objects.select_for_update(of=('self',)))
|
|
if connection.features.select_for_update_of_column:
|
|
expected = ['select_for_update_eucountry"."country_ptr_id']
|
|
else:
|
|
expected = ['select_for_update_eucountry']
|
|
expected = [connection.ops.quote_name(value) for value in expected]
|
|
self.assertTrue(self.has_for_update_sql(ctx.captured_queries, of=expected))
|
|
|
|
@skipUnlessDBFeature('has_select_for_update_of')
|
|
def test_for_update_sql_model_inheritance_ptr_generated_of(self):
|
|
with transaction.atomic(), CaptureQueriesContext(connection) as ctx:
|
|
list(EUCountry.objects.select_for_update(of=('self', 'country_ptr',)))
|
|
if connection.features.select_for_update_of_column:
|
|
expected = [
|
|
'select_for_update_eucountry"."country_ptr_id',
|
|
'select_for_update_country"."entity_ptr_id',
|
|
]
|
|
else:
|
|
expected = ['select_for_update_eucountry', 'select_for_update_country']
|
|
expected = [connection.ops.quote_name(value) for value in expected]
|
|
self.assertTrue(self.has_for_update_sql(ctx.captured_queries, of=expected))
|
|
|
|
@skipUnlessDBFeature('has_select_for_update_of')
|
|
def test_for_update_sql_related_model_inheritance_generated_of(self):
|
|
with transaction.atomic(), CaptureQueriesContext(connection) as ctx:
|
|
list(EUCity.objects.select_related('country').select_for_update(
|
|
of=('self', 'country'),
|
|
))
|
|
if connection.features.select_for_update_of_column:
|
|
expected = [
|
|
'select_for_update_eucity"."id',
|
|
'select_for_update_eucountry"."country_ptr_id',
|
|
]
|
|
else:
|
|
expected = ['select_for_update_eucity', 'select_for_update_eucountry']
|
|
expected = [connection.ops.quote_name(value) for value in expected]
|
|
self.assertTrue(self.has_for_update_sql(ctx.captured_queries, of=expected))
|
|
|
|
@skipUnlessDBFeature('has_select_for_update_of')
|
|
def test_for_update_sql_model_inheritance_nested_ptr_generated_of(self):
|
|
with transaction.atomic(), CaptureQueriesContext(connection) as ctx:
|
|
list(EUCity.objects.select_related('country').select_for_update(
|
|
of=('self', 'country__country_ptr',),
|
|
))
|
|
if connection.features.select_for_update_of_column:
|
|
expected = [
|
|
'select_for_update_eucity"."id',
|
|
'select_for_update_country"."entity_ptr_id',
|
|
]
|
|
else:
|
|
expected = ['select_for_update_eucity', 'select_for_update_country']
|
|
expected = [connection.ops.quote_name(value) for value in expected]
|
|
self.assertTrue(self.has_for_update_sql(ctx.captured_queries, of=expected))
|
|
|
|
@skipUnlessDBFeature('has_select_for_update_of')
|
|
def test_for_update_sql_multilevel_model_inheritance_ptr_generated_of(self):
|
|
with transaction.atomic(), CaptureQueriesContext(connection) as ctx:
|
|
list(EUCountry.objects.select_for_update(
|
|
of=('country_ptr', 'country_ptr__entity_ptr'),
|
|
))
|
|
if connection.features.select_for_update_of_column:
|
|
expected = [
|
|
'select_for_update_country"."entity_ptr_id',
|
|
'select_for_update_entity"."id',
|
|
]
|
|
else:
|
|
expected = ['select_for_update_country', 'select_for_update_entity']
|
|
expected = [connection.ops.quote_name(value) for value in expected]
|
|
self.assertTrue(self.has_for_update_sql(ctx.captured_queries, of=expected))
|
|
|
|
@skipUnlessDBFeature('has_select_for_update_of')
|
|
def test_for_update_sql_model_proxy_generated_of(self):
|
|
with transaction.atomic(), CaptureQueriesContext(connection) as ctx:
|
|
list(CityCountryProxy.objects.select_related(
|
|
'country',
|
|
).select_for_update(
|
|
of=('country',),
|
|
))
|
|
if connection.features.select_for_update_of_column:
|
|
expected = ['select_for_update_country"."entity_ptr_id']
|
|
else:
|
|
expected = ['select_for_update_country']
|
|
expected = [connection.ops.quote_name(value) for value in expected]
|
|
self.assertTrue(self.has_for_update_sql(ctx.captured_queries, of=expected))
|
|
|
|
@skipUnlessDBFeature('has_select_for_update_of')
|
|
def test_for_update_of_followed_by_values(self):
|
|
with transaction.atomic():
|
|
values = list(Person.objects.select_for_update(of=('self',)).values('pk'))
|
|
self.assertEqual(values, [{'pk': self.person.pk}])
|
|
|
|
@skipUnlessDBFeature('has_select_for_update_of')
|
|
def test_for_update_of_followed_by_values_list(self):
|
|
with transaction.atomic():
|
|
values = list(Person.objects.select_for_update(of=('self',)).values_list('pk'))
|
|
self.assertEqual(values, [(self.person.pk,)])
|
|
|
|
@skipUnlessDBFeature('has_select_for_update_of')
|
|
def test_for_update_of_self_when_self_is_not_selected(self):
|
|
"""
|
|
select_for_update(of=['self']) when the only columns selected are from
|
|
related tables.
|
|
"""
|
|
with transaction.atomic():
|
|
values = list(Person.objects.select_related('born').select_for_update(of=('self',)).values('born__name'))
|
|
self.assertEqual(values, [{'born__name': self.city1.name}])
|
|
|
|
@skipUnlessDBFeature('has_select_for_update_nowait')
|
|
def test_nowait_raises_error_on_block(self):
|
|
"""
|
|
If nowait is specified, we expect an error to be raised rather
|
|
than blocking.
|
|
"""
|
|
self.start_blocking_transaction()
|
|
status = []
|
|
|
|
thread = threading.Thread(
|
|
target=self.run_select_for_update,
|
|
args=(status,),
|
|
kwargs={'nowait': True},
|
|
)
|
|
|
|
thread.start()
|
|
time.sleep(1)
|
|
thread.join()
|
|
self.end_blocking_transaction()
|
|
self.assertIsInstance(status[-1], DatabaseError)
|
|
|
|
@skipUnlessDBFeature('has_select_for_update_skip_locked')
|
|
def test_skip_locked_skips_locked_rows(self):
|
|
"""
|
|
If skip_locked is specified, the locked row is skipped resulting in
|
|
Person.DoesNotExist.
|
|
"""
|
|
self.start_blocking_transaction()
|
|
status = []
|
|
thread = threading.Thread(
|
|
target=self.run_select_for_update,
|
|
args=(status,),
|
|
kwargs={'skip_locked': True},
|
|
)
|
|
thread.start()
|
|
time.sleep(1)
|
|
thread.join()
|
|
self.end_blocking_transaction()
|
|
self.assertIsInstance(status[-1], Person.DoesNotExist)
|
|
|
|
@skipIfDBFeature('has_select_for_update_nowait')
|
|
@skipUnlessDBFeature('has_select_for_update')
|
|
def test_unsupported_nowait_raises_error(self):
|
|
"""
|
|
NotSupportedError is raised if a SELECT...FOR UPDATE NOWAIT is run on
|
|
a database backend that supports FOR UPDATE but not NOWAIT.
|
|
"""
|
|
with self.assertRaisesMessage(NotSupportedError, 'NOWAIT is not supported on this database backend.'):
|
|
with transaction.atomic():
|
|
Person.objects.select_for_update(nowait=True).get()
|
|
|
|
@skipIfDBFeature('has_select_for_update_skip_locked')
|
|
@skipUnlessDBFeature('has_select_for_update')
|
|
def test_unsupported_skip_locked_raises_error(self):
|
|
"""
|
|
NotSupportedError is raised if a SELECT...FOR UPDATE SKIP LOCKED is run
|
|
on a database backend that supports FOR UPDATE but not SKIP LOCKED.
|
|
"""
|
|
with self.assertRaisesMessage(NotSupportedError, 'SKIP LOCKED is not supported on this database backend.'):
|
|
with transaction.atomic():
|
|
Person.objects.select_for_update(skip_locked=True).get()
|
|
|
|
@skipIfDBFeature('has_select_for_update_of')
|
|
@skipUnlessDBFeature('has_select_for_update')
|
|
def test_unsupported_of_raises_error(self):
|
|
"""
|
|
NotSupportedError is raised if a SELECT...FOR UPDATE OF... is run on
|
|
a database backend that supports FOR UPDATE but not OF.
|
|
"""
|
|
msg = 'FOR UPDATE OF is not supported on this database backend.'
|
|
with self.assertRaisesMessage(NotSupportedError, msg):
|
|
with transaction.atomic():
|
|
Person.objects.select_for_update(of=('self',)).get()
|
|
|
|
@skipIfDBFeature('has_select_for_no_key_update')
|
|
@skipUnlessDBFeature('has_select_for_update')
|
|
def test_unsuported_no_key_raises_error(self):
|
|
"""
|
|
NotSupportedError is raised if a SELECT...FOR NO KEY UPDATE... is run
|
|
on a database backend that supports FOR UPDATE but not NO KEY.
|
|
"""
|
|
msg = 'FOR NO KEY UPDATE is not supported on this database backend.'
|
|
with self.assertRaisesMessage(NotSupportedError, msg):
|
|
with transaction.atomic():
|
|
Person.objects.select_for_update(no_key=True).get()
|
|
|
|
@skipUnlessDBFeature('has_select_for_update', 'has_select_for_update_of')
|
|
def test_unrelated_of_argument_raises_error(self):
|
|
"""
|
|
FieldError is raised if a non-relation field is specified in of=(...).
|
|
"""
|
|
msg = (
|
|
'Invalid field name(s) given in select_for_update(of=(...)): %s. '
|
|
'Only relational fields followed in the query are allowed. '
|
|
'Choices are: self, born, born__country, '
|
|
'born__country__entity_ptr.'
|
|
)
|
|
invalid_of = [
|
|
('nonexistent',),
|
|
('name',),
|
|
('born__nonexistent',),
|
|
('born__name',),
|
|
('born__nonexistent', 'born__name'),
|
|
]
|
|
for of in invalid_of:
|
|
with self.subTest(of=of):
|
|
with self.assertRaisesMessage(FieldError, msg % ', '.join(of)):
|
|
with transaction.atomic():
|
|
Person.objects.select_related('born__country').select_for_update(of=of).get()
|
|
|
|
@skipUnlessDBFeature('has_select_for_update', 'has_select_for_update_of')
|
|
def test_related_but_unselected_of_argument_raises_error(self):
|
|
"""
|
|
FieldError is raised if a relation field that is not followed in the
|
|
query is specified in of=(...).
|
|
"""
|
|
msg = (
|
|
'Invalid field name(s) given in select_for_update(of=(...)): %s. '
|
|
'Only relational fields followed in the query are allowed. '
|
|
'Choices are: self, born, profile.'
|
|
)
|
|
for name in ['born__country', 'died', 'died__country']:
|
|
with self.subTest(name=name):
|
|
with self.assertRaisesMessage(FieldError, msg % name):
|
|
with transaction.atomic():
|
|
Person.objects.select_related(
|
|
'born', 'profile',
|
|
).exclude(profile=None).select_for_update(of=(name,)).get()
|
|
|
|
@skipUnlessDBFeature('has_select_for_update', 'has_select_for_update_of')
|
|
def test_model_inheritance_of_argument_raises_error_ptr_in_choices(self):
|
|
msg = (
|
|
'Invalid field name(s) given in select_for_update(of=(...)): '
|
|
'name. Only relational fields followed in the query are allowed. '
|
|
'Choices are: self, %s.'
|
|
)
|
|
with self.assertRaisesMessage(
|
|
FieldError,
|
|
msg % 'country, country__country_ptr, country__country_ptr__entity_ptr',
|
|
):
|
|
with transaction.atomic():
|
|
EUCity.objects.select_related(
|
|
'country',
|
|
).select_for_update(of=('name',)).get()
|
|
with self.assertRaisesMessage(FieldError, msg % 'country_ptr, country_ptr__entity_ptr'):
|
|
with transaction.atomic():
|
|
EUCountry.objects.select_for_update(of=('name',)).get()
|
|
|
|
@skipUnlessDBFeature('has_select_for_update', 'has_select_for_update_of')
|
|
def test_model_proxy_of_argument_raises_error_proxy_field_in_choices(self):
|
|
msg = (
|
|
'Invalid field name(s) given in select_for_update(of=(...)): '
|
|
'name. Only relational fields followed in the query are allowed. '
|
|
'Choices are: self, country, country__entity_ptr.'
|
|
)
|
|
with self.assertRaisesMessage(FieldError, msg):
|
|
with transaction.atomic():
|
|
CityCountryProxy.objects.select_related(
|
|
'country',
|
|
).select_for_update(of=('name',)).get()
|
|
|
|
@skipUnlessDBFeature('has_select_for_update', 'has_select_for_update_of')
|
|
def test_reverse_one_to_one_of_arguments(self):
|
|
"""
|
|
Reverse OneToOneFields may be included in of=(...) as long as NULLs
|
|
are excluded because LEFT JOIN isn't allowed in SELECT FOR UPDATE.
|
|
"""
|
|
with transaction.atomic():
|
|
person = Person.objects.select_related(
|
|
'profile',
|
|
).exclude(profile=None).select_for_update(of=('profile',)).get()
|
|
self.assertEqual(person.profile, self.person_profile)
|
|
|
|
@skipUnlessDBFeature('has_select_for_update')
|
|
def test_for_update_after_from(self):
|
|
features_class = connections['default'].features.__class__
|
|
attribute_to_patch = "%s.%s.for_update_after_from" % (features_class.__module__, features_class.__name__)
|
|
with mock.patch(attribute_to_patch, return_value=True):
|
|
with transaction.atomic():
|
|
self.assertIn('FOR UPDATE WHERE', str(Person.objects.filter(name='foo').select_for_update().query))
|
|
|
|
@skipUnlessDBFeature('has_select_for_update')
|
|
def test_for_update_requires_transaction(self):
|
|
"""
|
|
A TransactionManagementError is raised
|
|
when a select_for_update query is executed outside of a transaction.
|
|
"""
|
|
msg = 'select_for_update cannot be used outside of a transaction.'
|
|
with self.assertRaisesMessage(transaction.TransactionManagementError, msg):
|
|
list(Person.objects.all().select_for_update())
|
|
|
|
@skipUnlessDBFeature('has_select_for_update')
|
|
def test_for_update_requires_transaction_only_in_execution(self):
|
|
"""
|
|
No TransactionManagementError is raised
|
|
when select_for_update is invoked outside of a transaction -
|
|
only when the query is executed.
|
|
"""
|
|
people = Person.objects.all().select_for_update()
|
|
msg = 'select_for_update cannot be used outside of a transaction.'
|
|
with self.assertRaisesMessage(transaction.TransactionManagementError, msg):
|
|
list(people)
|
|
|
|
@skipUnlessDBFeature('supports_select_for_update_with_limit')
|
|
def test_select_for_update_with_limit(self):
|
|
other = Person.objects.create(name='Grappeli', born=self.city1, died=self.city2)
|
|
with transaction.atomic():
|
|
qs = list(Person.objects.all().order_by('pk').select_for_update()[1:2])
|
|
self.assertEqual(qs[0], other)
|
|
|
|
@skipIfDBFeature('supports_select_for_update_with_limit')
|
|
def test_unsupported_select_for_update_with_limit(self):
|
|
msg = 'LIMIT/OFFSET is not supported with select_for_update on this database backend.'
|
|
with self.assertRaisesMessage(NotSupportedError, msg):
|
|
with transaction.atomic():
|
|
list(Person.objects.all().order_by('pk').select_for_update()[1:2])
|
|
|
|
def run_select_for_update(self, status, **kwargs):
|
|
"""
|
|
Utility method that runs a SELECT FOR UPDATE against all
|
|
Person instances. After the select_for_update, it attempts
|
|
to update the name of the only record, save, and commit.
|
|
|
|
This function expects to run in a separate thread.
|
|
"""
|
|
status.append('started')
|
|
try:
|
|
# We need to enter transaction management again, as this is done on
|
|
# per-thread basis
|
|
with transaction.atomic():
|
|
person = Person.objects.select_for_update(**kwargs).get()
|
|
person.name = 'Fred'
|
|
person.save()
|
|
except (DatabaseError, Person.DoesNotExist) as e:
|
|
status.append(e)
|
|
finally:
|
|
# This method is run in a separate thread. It uses its own
|
|
# database connection. Close it without waiting for the GC.
|
|
connection.close()
|
|
|
|
@skipUnlessDBFeature('has_select_for_update')
|
|
@skipUnlessDBFeature('supports_transactions')
|
|
def test_block(self):
|
|
"""
|
|
A thread running a select_for_update that accesses rows being touched
|
|
by a similar operation on another connection blocks correctly.
|
|
"""
|
|
# First, let's start the transaction in our thread.
|
|
self.start_blocking_transaction()
|
|
|
|
# Now, try it again using the ORM's select_for_update
|
|
# facility. Do this in a separate thread.
|
|
status = []
|
|
thread = threading.Thread(
|
|
target=self.run_select_for_update, args=(status,)
|
|
)
|
|
|
|
# The thread should immediately block, but we'll sleep
|
|
# for a bit to make sure.
|
|
thread.start()
|
|
sanity_count = 0
|
|
while len(status) != 1 and sanity_count < 10:
|
|
sanity_count += 1
|
|
time.sleep(1)
|
|
if sanity_count >= 10:
|
|
raise ValueError('Thread did not run and block')
|
|
|
|
# Check the person hasn't been updated. Since this isn't
|
|
# using FOR UPDATE, it won't block.
|
|
p = Person.objects.get(pk=self.person.pk)
|
|
self.assertEqual('Reinhardt', p.name)
|
|
|
|
# When we end our blocking transaction, our thread should
|
|
# be able to continue.
|
|
self.end_blocking_transaction()
|
|
thread.join(5.0)
|
|
|
|
# Check the thread has finished. Assuming it has, we should
|
|
# find that it has updated the person's name.
|
|
self.assertFalse(thread.is_alive())
|
|
|
|
# We must commit the transaction to ensure that MySQL gets a fresh read,
|
|
# since by default it runs in REPEATABLE READ mode
|
|
transaction.commit()
|
|
|
|
p = Person.objects.get(pk=self.person.pk)
|
|
self.assertEqual('Fred', p.name)
|
|
|
|
@skipUnlessDBFeature('has_select_for_update')
|
|
def test_raw_lock_not_available(self):
|
|
"""
|
|
Running a raw query which can't obtain a FOR UPDATE lock raises
|
|
the correct exception
|
|
"""
|
|
self.start_blocking_transaction()
|
|
|
|
def raw(status):
|
|
try:
|
|
list(
|
|
Person.objects.raw(
|
|
'SELECT * FROM %s %s' % (
|
|
Person._meta.db_table,
|
|
connection.ops.for_update_sql(nowait=True)
|
|
)
|
|
)
|
|
)
|
|
except DatabaseError as e:
|
|
status.append(e)
|
|
finally:
|
|
# This method is run in a separate thread. It uses its own
|
|
# database connection. Close it without waiting for the GC.
|
|
# Connection cannot be closed on Oracle because cursor is still
|
|
# open.
|
|
if connection.vendor != 'oracle':
|
|
connection.close()
|
|
|
|
status = []
|
|
thread = threading.Thread(target=raw, kwargs={'status': status})
|
|
thread.start()
|
|
time.sleep(1)
|
|
thread.join()
|
|
self.end_blocking_transaction()
|
|
self.assertIsInstance(status[-1], DatabaseError)
|
|
|
|
@skipUnlessDBFeature('has_select_for_update')
|
|
@override_settings(DATABASE_ROUTERS=[TestRouter()])
|
|
def test_select_for_update_on_multidb(self):
|
|
query = Person.objects.select_for_update()
|
|
self.assertEqual(router.db_for_write(Person), query.db)
|
|
|
|
@skipUnlessDBFeature('has_select_for_update')
|
|
def test_select_for_update_with_get(self):
|
|
with transaction.atomic():
|
|
person = Person.objects.select_for_update().get(name='Reinhardt')
|
|
self.assertEqual(person.name, 'Reinhardt')
|
|
|
|
def test_nowait_and_skip_locked(self):
|
|
with self.assertRaisesMessage(ValueError, 'The nowait option cannot be used with skip_locked.'):
|
|
Person.objects.select_for_update(nowait=True, skip_locked=True)
|
|
|
|
def test_ordered_select_for_update(self):
|
|
"""
|
|
Subqueries should respect ordering as an ORDER BY clause may be useful
|
|
to specify a row locking order to prevent deadlocks (#27193).
|
|
"""
|
|
with transaction.atomic():
|
|
qs = Person.objects.filter(id__in=Person.objects.order_by('-id').select_for_update())
|
|
self.assertIn('ORDER BY', str(qs.query))
|