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