Fixed #6433 -- Handle some varied PostgreSQL version strings (beta versions and

import re

from django.db.backends import BaseDatabaseOperations

server_version_re = re.compile(r'PostgreSQL (\d{1,2})\.(\d{1,2})\.?(\d{1,2})?')

# This DatabaseOperations class lives in here instead of base.py because it's

# used by both the 'postgresql' and 'postgresql_psycopg2' backends.

            from django.db import connection

            cursor = connection.cursor()

            cursor.execute("SELECT version()")

            self._postgres_version = [int(val) for val in cursor.fetchone()[0].split()[1].split('.')]

            version_string = cursor.fetchone()[0]

            m = server_version_re.match(version_string)

            if not m:

                raise Exception('Unable to determine PostgreSQL version from version() function string: %r' % version_string)

            self._postgres_version = [int(val) for val in m.groups() if val]

        return self._postgres_version

    postgres_version = property(_get_postgres_version)