212 lines
7.7 KiB
Python
212 lines
7.7 KiB
Python
"""
|
|
PostgreSQL database backend for Django.
|
|
|
|
Requires psycopg 2: http://initd.org/projects/psycopg2
|
|
"""
|
|
|
|
from django.conf import settings
|
|
from django.db.backends import (BaseDatabaseFeatures, BaseDatabaseWrapper,
|
|
BaseDatabaseValidation)
|
|
from django.db.backends.postgresql_psycopg2.operations import DatabaseOperations
|
|
from django.db.backends.postgresql_psycopg2.client import DatabaseClient
|
|
from django.db.backends.postgresql_psycopg2.creation import DatabaseCreation
|
|
from django.db.backends.postgresql_psycopg2.version import get_version
|
|
from django.db.backends.postgresql_psycopg2.introspection import DatabaseIntrospection
|
|
from django.db.backends.postgresql_psycopg2.schema import DatabaseSchemaEditor
|
|
from django.db.utils import InterfaceError
|
|
from django.utils.encoding import force_str
|
|
from django.utils.functional import cached_property
|
|
from django.utils.safestring import SafeText, SafeBytes
|
|
from django.utils.timezone import utc
|
|
|
|
try:
|
|
import psycopg2 as Database
|
|
import psycopg2.extensions
|
|
except ImportError as e:
|
|
from django.core.exceptions import ImproperlyConfigured
|
|
raise ImproperlyConfigured("Error loading psycopg2 module: %s" % e)
|
|
|
|
DatabaseError = Database.DatabaseError
|
|
IntegrityError = Database.IntegrityError
|
|
|
|
psycopg2.extensions.register_type(psycopg2.extensions.UNICODE)
|
|
psycopg2.extensions.register_type(psycopg2.extensions.UNICODEARRAY)
|
|
psycopg2.extensions.register_adapter(SafeBytes, psycopg2.extensions.QuotedString)
|
|
psycopg2.extensions.register_adapter(SafeText, psycopg2.extensions.QuotedString)
|
|
|
|
|
|
def utc_tzinfo_factory(offset):
|
|
if offset != 0:
|
|
raise AssertionError("database connection isn't set to UTC")
|
|
return utc
|
|
|
|
|
|
class DatabaseFeatures(BaseDatabaseFeatures):
|
|
needs_datetime_string_cast = False
|
|
can_return_id_from_insert = True
|
|
has_real_datatype = True
|
|
can_defer_constraint_checks = True
|
|
has_select_for_update = True
|
|
has_select_for_update_nowait = True
|
|
has_bulk_insert = True
|
|
uses_savepoints = True
|
|
can_release_savepoints = True
|
|
supports_tablespaces = True
|
|
supports_transactions = True
|
|
can_introspect_ip_address_field = True
|
|
can_introspect_small_integer_field = True
|
|
can_distinct_on_fields = True
|
|
can_rollback_ddl = True
|
|
supports_combined_alters = True
|
|
nulls_order_largest = True
|
|
closed_cursor_error_class = InterfaceError
|
|
has_case_insensitive_like = False
|
|
requires_sqlparse_for_splitting = False
|
|
|
|
|
|
class DatabaseWrapper(BaseDatabaseWrapper):
|
|
vendor = 'postgresql'
|
|
operators = {
|
|
'exact': '= %s',
|
|
'iexact': '= UPPER(%s)',
|
|
'contains': 'LIKE %s',
|
|
'icontains': 'LIKE UPPER(%s)',
|
|
'regex': '~ %s',
|
|
'iregex': '~* %s',
|
|
'gt': '> %s',
|
|
'gte': '>= %s',
|
|
'lt': '< %s',
|
|
'lte': '<= %s',
|
|
'startswith': 'LIKE %s',
|
|
'endswith': 'LIKE %s',
|
|
'istartswith': 'LIKE UPPER(%s)',
|
|
'iendswith': 'LIKE UPPER(%s)',
|
|
}
|
|
|
|
pattern_ops = {
|
|
'startswith': "LIKE %s || '%%%%'",
|
|
'istartswith': "LIKE UPPER(%s) || '%%%%'",
|
|
}
|
|
|
|
Database = Database
|
|
|
|
def __init__(self, *args, **kwargs):
|
|
super(DatabaseWrapper, self).__init__(*args, **kwargs)
|
|
|
|
opts = self.settings_dict["OPTIONS"]
|
|
RC = psycopg2.extensions.ISOLATION_LEVEL_READ_COMMITTED
|
|
self.isolation_level = opts.get('isolation_level', RC)
|
|
|
|
self.features = DatabaseFeatures(self)
|
|
self.ops = DatabaseOperations(self)
|
|
self.client = DatabaseClient(self)
|
|
self.creation = DatabaseCreation(self)
|
|
self.introspection = DatabaseIntrospection(self)
|
|
self.validation = BaseDatabaseValidation(self)
|
|
|
|
def get_connection_params(self):
|
|
settings_dict = self.settings_dict
|
|
# None may be used to connect to the default 'postgres' db
|
|
if settings_dict['NAME'] == '':
|
|
from django.core.exceptions import ImproperlyConfigured
|
|
raise ImproperlyConfigured(
|
|
"settings.DATABASES is improperly configured. "
|
|
"Please supply the NAME value.")
|
|
conn_params = {
|
|
'database': settings_dict['NAME'] or 'postgres',
|
|
}
|
|
conn_params.update(settings_dict['OPTIONS'])
|
|
if 'autocommit' in conn_params:
|
|
del conn_params['autocommit']
|
|
if 'isolation_level' in conn_params:
|
|
del conn_params['isolation_level']
|
|
if settings_dict['USER']:
|
|
conn_params['user'] = settings_dict['USER']
|
|
if settings_dict['PASSWORD']:
|
|
conn_params['password'] = force_str(settings_dict['PASSWORD'])
|
|
if settings_dict['HOST']:
|
|
conn_params['host'] = settings_dict['HOST']
|
|
if settings_dict['PORT']:
|
|
conn_params['port'] = settings_dict['PORT']
|
|
return conn_params
|
|
|
|
def get_new_connection(self, conn_params):
|
|
return Database.connect(**conn_params)
|
|
|
|
def init_connection_state(self):
|
|
settings_dict = self.settings_dict
|
|
self.connection.set_client_encoding('UTF8')
|
|
tz = 'UTC' if settings.USE_TZ else settings_dict.get('TIME_ZONE')
|
|
if tz:
|
|
try:
|
|
get_parameter_status = self.connection.get_parameter_status
|
|
except AttributeError:
|
|
# psycopg2 < 2.0.12 doesn't have get_parameter_status
|
|
conn_tz = None
|
|
else:
|
|
conn_tz = get_parameter_status('TimeZone')
|
|
|
|
if conn_tz != tz:
|
|
cursor = self.connection.cursor()
|
|
try:
|
|
cursor.execute(self.ops.set_time_zone_sql(), [tz])
|
|
finally:
|
|
cursor.close()
|
|
# Commit after setting the time zone (see #17062)
|
|
if not self.get_autocommit():
|
|
self.connection.commit()
|
|
|
|
def create_cursor(self):
|
|
cursor = self.connection.cursor()
|
|
cursor.tzinfo_factory = utc_tzinfo_factory if settings.USE_TZ else None
|
|
return cursor
|
|
|
|
def _set_isolation_level(self, isolation_level):
|
|
assert isolation_level in range(1, 5) # Use set_autocommit for level = 0
|
|
if self.psycopg2_version >= (2, 4, 2):
|
|
self.connection.set_session(isolation_level=isolation_level)
|
|
else:
|
|
self.connection.set_isolation_level(isolation_level)
|
|
|
|
def _set_autocommit(self, autocommit):
|
|
with self.wrap_database_errors:
|
|
if self.psycopg2_version >= (2, 4, 2):
|
|
self.connection.autocommit = autocommit
|
|
else:
|
|
if autocommit:
|
|
level = psycopg2.extensions.ISOLATION_LEVEL_AUTOCOMMIT
|
|
else:
|
|
level = self.isolation_level
|
|
self.connection.set_isolation_level(level)
|
|
|
|
def check_constraints(self, table_names=None):
|
|
"""
|
|
To check constraints, we set constraints to immediate. Then, when, we're done we must ensure they
|
|
are returned to deferred.
|
|
"""
|
|
self.cursor().execute('SET CONSTRAINTS ALL IMMEDIATE')
|
|
self.cursor().execute('SET CONSTRAINTS ALL DEFERRED')
|
|
|
|
def is_usable(self):
|
|
try:
|
|
# Use a psycopg cursor directly, bypassing Django's utilities.
|
|
self.connection.cursor().execute("SELECT 1")
|
|
except Database.Error:
|
|
return False
|
|
else:
|
|
return True
|
|
|
|
def schema_editor(self, *args, **kwargs):
|
|
"Returns a new instance of this backend's SchemaEditor"
|
|
return DatabaseSchemaEditor(self, *args, **kwargs)
|
|
|
|
@cached_property
|
|
def psycopg2_version(self):
|
|
version = psycopg2.__version__.split(' ', 1)[0]
|
|
return tuple(int(v) for v in version.split('.'))
|
|
|
|
@cached_property
|
|
def pg_version(self):
|
|
with self.temporary_connection():
|
|
return get_version(self.connection)
|