1 """

     2 PostgreSQL database backend for Django.

     3 

     4 Requires psycopg 2: http://initd.org/projects/psycopg2

     5 """

     6 

     7 from django.db.backends import BaseDatabaseWrapper, BaseDatabaseFeatures

     8 from django.db.backends.postgresql.operations import DatabaseOperations as PostgresqlDatabaseOperations

     9 from django.utils.safestring import SafeUnicode

    10 try:

    11     import psycopg2 as Database

    12     import psycopg2.extensions

    13 except ImportError, e:

    14     from django.core.exceptions import ImproperlyConfigured

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

    16 

    17 DatabaseError = Database.DatabaseError

    18 IntegrityError = Database.IntegrityError

    19 

    20 psycopg2.extensions.register_type(psycopg2.extensions.UNICODE)

    21 psycopg2.extensions.register_adapter(SafeUnicode, psycopg2.extensions.QuotedString)

    22 

    23 class DatabaseFeatures(BaseDatabaseFeatures):

    24     needs_datetime_string_cast = False

    25 

    26 class DatabaseOperations(PostgresqlDatabaseOperations):

    27     def last_executed_query(self, cursor, sql, params):

    28         # With psycopg2, cursor objects have a "query" attribute that is the

    29         # exact query sent to the database. See docs here:

    30         # http://www.initd.org/tracker/psycopg/wiki/psycopg2_documentation#postgresql-status-message-and-executed-query

    31         return cursor.query

    32 

    33 class DatabaseWrapper(BaseDatabaseWrapper):

    34     features = DatabaseFeatures()

    35     ops = DatabaseOperations()

    36     operators = {

    37         'exact': '= %s',

    38         'iexact': 'ILIKE %s',

    39         'contains': 'LIKE %s',

    40         'icontains': 'ILIKE %s',

    41         'regex': '~ %s',

    42         'iregex': '~* %s',

    43         'gt': '> %s',

    44         'gte': '>= %s',

    45         'lt': '< %s',

    46         'lte': '<= %s',

    47         'startswith': 'LIKE %s',

    48         'endswith': 'LIKE %s',

    49         'istartswith': 'ILIKE %s',

    50         'iendswith': 'ILIKE %s',

    51     }

    52 

    53     def _cursor(self, settings):

    54         set_tz = False

    55         if self.connection is None:

    56             set_tz = True

    57             if settings.DATABASE_NAME == '':

    58                 from django.core.exceptions import ImproperlyConfigured

    59                 raise ImproperlyConfigured("You need to specify DATABASE_NAME in your Django settings file.")

    60             conn_string = "dbname=%s" % settings.DATABASE_NAME

    61             if settings.DATABASE_USER:

    62                 conn_string = "user=%s %s" % (settings.DATABASE_USER, conn_string)

    63             if settings.DATABASE_PASSWORD:

    64                 conn_string += " password='%s'" % settings.DATABASE_PASSWORD

    65             if settings.DATABASE_HOST:

    66                 conn_string += " host=%s" % settings.DATABASE_HOST

    67             if settings.DATABASE_PORT:

    68                 conn_string += " port=%s" % settings.DATABASE_PORT

    69             self.connection = Database.connect(conn_string, **self.options)

    70             self.connection.set_isolation_level(1) # make transactions transparent to all cursors

    71             self.connection.set_client_encoding('UTF8')

    72         cursor = self.connection.cursor()

    73         cursor.tzinfo_factory = None

    74         if set_tz:

    75             cursor.execute("SET TIME ZONE %s", [settings.TIME_ZONE])

    76         return cursor