Fixed #24335 -- Bumped required psycopg2 version to 2.4.5 (2.5 for contrib.postgres).

"""

from django.conf import settings

from django.core.exceptions import ImproperlyConfigured

from django.db.backends.base.base import BaseDatabaseWrapper

from django.db.backends.base.validation import BaseDatabaseValidation

from django.utils.encoding import force_str

    import psycopg2.extensions

    import psycopg2.extras

except ImportError as e:

    from django.core.exceptions import ImproperlyConfigured

    raise ImproperlyConfigured("Error loading psycopg2 module: %s" % e)

def psycopg2_version():

    version = psycopg2.__version__.split(' ', 1)[0]

    return tuple(int(v) for v in version.split('.') if v.isdigit())

PSYCOPG2_VERSION = psycopg2_version()

if PSYCOPG2_VERSION < (2, 4, 5):

    raise ImproperlyConfigured("psycopg2_version 2.4.5 or newer is required; you have %s" % psycopg2.__version__)

# Some of these import psycopg2, so import them after checking if it's installed.

from .client import DatabaseClient                          # isort:skip

from .creation import DatabaseCreation                      # isort:skip

        # - after connecting to the database in order to obtain the database's

        #   default when no value is explicitly specified in options.

        # - before calling _set_autocommit() because if autocommit is on, that

        #   will set connection.isolation_level to ISOLATION_LEVEL_AUTOCOMMIT;

        #   and if autocommit is off, on psycopg2 < 2.4.2, _set_autocommit()

        #   needs self.isolation_level.

        #   will set connection.isolation_level to ISOLATION_LEVEL_AUTOCOMMIT.

        options = self.settings_dict['OPTIONS']

        try:

            self.isolation_level = options['isolation_level']

        except KeyError:

            self.isolation_level = connection.isolation_level

        else:

            # Set the isolation level to the value from OPTIONS. This isn't

            # needed on psycopg2 < 2.4.2 because it happens as a side-effect

            # of _set_autocommit(False).

            if (self.isolation_level != connection.isolation_level and

                    self.psycopg2_version >= (2, 4, 2)):

            # Set the isolation level to the value from OPTIONS.

            if self.isolation_level != connection.isolation_level:

                connection.set_session(isolation_level=self.isolation_level)

        return connection

        self.connection.set_client_encoding('UTF8')

        tz = self.settings_dict['TIME_ZONE']

        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')

        conn_tz = self.connection.get_parameter_status('TimeZone')

        if conn_tz != tz:

            cursor = self.connection.cursor()

    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):

        """

    @cached_property

    def psycopg2_version(self):

        version = psycopg2.__version__.split(' ', 1)[0]

        return tuple(int(v) for v in version.split('.') if v.isdigit())

        return PSYCOPG2_VERSION

    @cached_property

    def pg_version(self):

``django.contrib.postgres``

===========================

.. module:: django.contrib.postgres

    :synopsis: PostgreSQL-specific fields and features

.. versionadded:: 1.8

PostgreSQL has a number of features which are not shared by the other databases

Django supports. This optional module contains model fields and form fields for

a number of PostgreSQL specific data types.

Psycopg2 2.5 or higher is required.

.. note::

    Django is, and will continue to be, a database-agnostic web framework. We

    would encourage those writing reusable applications for the Django

PostgreSQL notes

================

Django supports PostgreSQL 9.0 and higher. It requires the use of Psycopg2

2.0.9 or higher.

Django supports PostgreSQL 9.0 and higher. It requires the use of `psycopg2`_

2.4.5 or higher (or 2.5+ if you want to use :mod:`django.contrib.postgres`).

.. _psycopg2: http://initd.org/psycopg/

If you're on Windows, check out the unofficial `compiled Windows version`_

of psycopg2.

This also includes dropping support for PostGIS 1.3 and 1.4 as these versions

are not supported on versions of PostgreSQL later than 8.4.

Django also now requires the use of Psycopg2 version 2.0.9 or higher.

Django also now requires the use of Psycopg2 version 2.4.5 or higher (or 2.5+

if you want to use :mod:`django.contrib.postgres`).

Support for MySQL versions older than 5.5

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

            self.assertIn('::text', do.lookup_cast(lookup))

    def test_correct_extraction_psycopg2_version(self):

        from django.db.backends.postgresql_psycopg2.base import DatabaseWrapper

        from django.db.backends.postgresql_psycopg2.base import psycopg2_version

        version_path = 'django.db.backends.postgresql_psycopg2.base.Database.__version__'

        with mock.patch(version_path, '2.6.9'):

            self.assertEqual(DatabaseWrapper.psycopg2_version.__get__(self), (2, 6, 9))

            self.assertEqual(psycopg2_version(), (2, 6, 9))

        with mock.patch(version_path, '2.5.dev0'):

            self.assertEqual(DatabaseWrapper.psycopg2_version.__get__(self), (2, 5))

            self.assertEqual(psycopg2_version(), (2, 5))

class DateQuotingTest(TestCase):