"""
PostgreSQL database backend for Django.
Requires psycopg 2: http://initd.org/projects/psycopg2
"""
import sys
from django.db import utils
from django.db.backends import *
from django.db.backends.signals import connection_created
from django.db.backends.postgresql.operations import DatabaseOperations
from django.db.backends.postgresql.client import DatabaseClient
from django.db.backends.postgresql.creation import DatabaseCreation
from django.db.backends.postgresql.version import get_version
from django.db.backends.postgresql_psycopg2.introspection import DatabaseIntrospection
from django.utils.safestring import SafeUnicode,SafeString
try:
import psycopg2 as Database
import psycopg2.extensions
except ImportError, 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_adapter(SafeString, psycopg2.extensions.QuotedString)
psycopg2.extensions.register_adapter(SafeUnicode, psycopg2.extensions.QuotedString)
class CursorWrapper(object):
"""
A thin wrapper around psycopg2's normal cursor class so that we can catch
particular exception instances and reraise them with the right types.
"""
def __init__(self, cursor):
self.cursor = cursor
def execute(self, query, args=None):
try:
return self.cursor.execute(query, args)
except Database.IntegrityError, e:
raise utils.IntegrityError, utils.IntegrityError(*tuple(e)), sys.exc_info()[2]
except Database.DatabaseError, e:
raise utils.DatabaseError, utils.DatabaseError(*tuple(e)), sys.exc_info()[2]
def executemany(self, query, args):
try:
return self.cursor.executemany(query, args)
except Database.IntegrityError, e:
raise utils.IntegrityError, utils.IntegrityError(*tuple(e)), sys.exc_info()[2]
except Database.DatabaseError, e:
raise utils.DatabaseError, utils.DatabaseError(*tuple(e)), sys.exc_info()[2]
def __getattr__(self, attr):
if attr in self.__dict__:
return self.__dict__[attr]
else:
return getattr(self.cursor, attr)
def __iter__(self):
return iter(self.cursor)
class DatabaseFeatures(BaseDatabaseFeatures):
needs_datetime_string_cast = False
can_return_id_from_insert = False
class DatabaseOperations(PostgresqlDatabaseOperations):
def last_executed_query(self, cursor, sql, params):
# With psycopg2, cursor objects have a "query" attribute that is the
# exact query sent to the database. See docs here:
# http://www.initd.org/tracker/psycopg/wiki/psycopg2_documentation#postgresql-status-message-and-executed-query
return cursor.query
def return_insert_id(self):
return "RETURNING %s", ()
class DatabaseWrapper(BaseDatabaseWrapper):
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)',
}
def __init__(self, *args, **kwargs):
super(DatabaseWrapper, self).__init__(*args, **kwargs)
self.features = DatabaseFeatures()
autocommit = self.settings_dict["OPTIONS"].get('autocommit', False)
self.features.uses_autocommit = autocommit
self._set_isolation_level(int(not autocommit))
self.ops = DatabaseOperations(self)
self.client = DatabaseClient(self)
self.creation = DatabaseCreation(self)
self.introspection = DatabaseIntrospection(self)
self.validation = BaseDatabaseValidation(self)
def _cursor(self):
new_connection = False
set_tz = False
settings_dict = self.settings_dict
if self.connection is None:
new_connection = True
set_tz = settings_dict.get('TIME_ZONE')
if settings_dict['NAME'] == '':
from django.core.exceptions import ImproperlyConfigured
raise ImproperlyConfigured("You need to specify NAME in your Django settings file.")
conn_params = {
'database': settings_dict['NAME'],
}
conn_params.update(settings_dict['OPTIONS'])
if 'autocommit' in conn_params:
del conn_params['autocommit']
if settings_dict['USER']:
conn_params['user'] = settings_dict['USER']
if settings_dict['PASSWORD']:
conn_params['password'] = settings_dict['PASSWORD']
if settings_dict['HOST']:
conn_params['host'] = settings_dict['HOST']
if settings_dict['PORT']:
conn_params['port'] = settings_dict['PORT']
self.connection = Database.connect(**conn_params)
self.connection.set_client_encoding('UTF8')
self.connection.set_isolation_level(self.isolation_level)
connection_created.send(sender=self.__class__)
cursor = self.connection.cursor()
cursor.tzinfo_factory = None
if new_connection:
if set_tz:
cursor.execute("SET TIME ZONE %s", [settings_dict['TIME_ZONE']])
if not hasattr(self, '_version'):
self.__class__._version = get_version(cursor)
if self._version[0:2] < (8, 0):
# No savepoint support for earlier version of PostgreSQL.
self.features.uses_savepoints = False
if self.features.uses_autocommit:
if self._version[0:2] < (8, 2):
# FIXME: Needs extra code to do reliable model insert
# handling, so we forbid it for now.
from django.core.exceptions import ImproperlyConfigured
raise ImproperlyConfigured("You cannot use autocommit=True with PostgreSQL prior to 8.2 at the moment.")
else:
# FIXME: Eventually we're enable this by default for
# versions that support it, but, right now, that's hard to
# do without breaking other things (#10509).
self.features.can_return_id_from_insert = True
return CursorWrapper(cursor)
def _enter_transaction_management(self, managed):
"""
Switch the isolation level when needing transaction support, so that
the same transaction is visible across all the queries.
"""
if self.features.uses_autocommit and managed and not self.isolation_level:
self._set_isolation_level(1)
def _leave_transaction_management(self, managed):
"""
If the normal operating mode is "autocommit", switch back to that when
leaving transaction management.
"""
if self.features.uses_autocommit and not managed and self.isolation_level:
self._set_isolation_level(0)
def _set_isolation_level(self, level):
"""
Do all the related feature configurations for changing isolation
levels. This doesn't touch the uses_autocommit feature, since that
controls the movement *between* isolation levels.
"""
assert level in (0, 1)
try:
if self.connection is not None:
self.connection.set_isolation_level(level)
finally:
self.isolation_level = level
self.features.uses_savepoints = bool(level)
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