Python django.db.connections.all() Examples

def _nodb_connection(self):
        nodb_connection = super()._nodb_connection
        try:
            nodb_connection.ensure_connection()
        except (Database.DatabaseError, WrappedDatabaseError):
            warnings.warn(
                "Normally Django will use a connection to the 'postgres' database "
                "to avoid running initialization queries against the production "
                "database when it's not needed (for example, when running tests). "
                "Django was unable to create a connection to the 'postgres' database "
                "and will use the first PostgreSQL database instead.",
                RuntimeWarning
            )
            for connection in connections.all():
                if connection.vendor == 'postgresql' and connection.settings_dict['NAME'] != 'postgres':
                    return self.__class__(
                        {**self.settings_dict, 'NAME': connection.settings_dict['NAME']},
                        alias=self.alias,
                        allow_thread_sharing=False,
                    )
        return nodb_connection 

def ready(self):
        # Connections may already exist before we are called.
        for conn in connections.all():
            if conn.vendor == 'postgresql':
                conn.introspection.data_types_reverse.update({
                    3802: 'django.contrib.postgresql.fields.JSONField',
                    3904: 'django.contrib.postgresql.fields.IntegerRangeField',
                    3906: 'django.contrib.postgresql.fields.FloatRangeField',
                    3910: 'django.contrib.postgresql.fields.DateTimeRangeField',
                    3912: 'django.contrib.postgresql.fields.DateRangeField',
                    3926: 'django.contrib.postgresql.fields.BigIntegerRangeField',
                })
                if conn.connection is not None:
                    register_type_handlers(conn)
        connection_created.connect(register_type_handlers)
        CharField.register_lookup(Unaccent)
        TextField.register_lookup(Unaccent)
        CharField.register_lookup(SearchLookup)
        TextField.register_lookup(SearchLookup)
        CharField.register_lookup(TrigramSimilar)
        TextField.register_lookup(TrigramSimilar) 

def __init__(self, *args, **kwargs):
        # Call super first, so the MiddlewareMixin's __init__ does its thing.
        super(QueryCountMiddleware, self).__init__(*args, **kwargs)

        if settings.DEBUG:
            self.request_path = None
            self.stats = {"request": {}, "response": {}}
            self.dbs = [c.alias for c in connections.all()]
            self.queries = Counter()
            self._reset_stats()

            self._start_time = None
            self._end_time = None
            self.host = None  # The HTTP_HOST pulled from the request

            # colorizing methods
            self.white = termcolors.make_style(opts=('bold',), fg='white')
            self.red = termcolors.make_style(opts=('bold',), fg='red')
            self.yellow = termcolors.make_style(opts=('bold',), fg='yellow')
            self.green = termcolors.make_style(fg='green')

            # query type detection regex
            # TODO: make stats classification regex more robust
            self.threshold = QC_SETTINGS['THRESHOLDS'] 

def _count_queries(self, which):
        for c in connections.all():
            for q in c.queries:
                if not self._ignore_sql(q):
                    if q.get('sql') and self.READ_QUERY_REGEX.search(q['sql']) is not None:
                        self.stats[which][c.alias]['reads'] += 1
                    else:
                        self.stats[which][c.alias]['writes'] += 1
                    self.stats[which][c.alias]['total'] += 1
                    self.queries[q['sql']] += 1

            # We'll show the worst offender; i.e. the query with the most duplicates
            duplicates = self.queries.most_common(1)
            if duplicates:
                sql, count = duplicates[0]
                self.stats[which][c.alias]['duplicates'] = count
            else:
                self.stats[which][c.alias]['duplicates'] = 0 

def update_connections_time_zone(**kwargs):
    if kwargs['setting'] == 'TIME_ZONE':
        # Reset process time zone
        if hasattr(time, 'tzset'):
            if kwargs['value']:
                os.environ['TZ'] = kwargs['value']
            else:
                os.environ.pop('TZ', None)
            time.tzset()

        # Reset local time zone cache
        timezone.get_default_timezone.cache_clear()

    # Reset the database connections' time zone
    if kwargs['setting'] in {'TIME_ZONE', 'USE_TZ'}:
        for conn in connections.all():
            try:
                del conn.timezone
            except AttributeError:
                pass
            try:
                del conn.timezone_name
            except AttributeError:
                pass
            conn.ensure_timezone() 

def prepare_task_execution():
        """

        Clearing of old database connections for CONN_MAX_AGE option (database connection settings)

        """
        if not TaskUtils.is_celery_worker():
            return

        try:
            if TaskUtils.__connection_initialization_finished:
                close_old_connections()
            else:
                for conn in connections.all():
                    conn.close()
                    TaskUtils.__connection_initialization_finished = True
        except Exception:
            pass 

def _post_teardown(self):
        """ Performs any post-test things. This includes:

            * Putting back the original ROOT_URLCONF if it was changed.
            * Force closing the connection, so that the next test gets
              a clean cursor.
        """
        self._fixture_teardown()
        self._urlconf_teardown()
        # Some DB cursors include SQL statements as part of cursor
        # creation. If you have a test that does rollback, the effect
        # of these statements is lost, which can effect the operation
        # of tests (e.g., losing a timezone setting causing objects to
        # be created with the wrong time).
        # To make sure this doesn't happen, get a clean connection at the
        # start of every test.
        for conn in connections.all():
            conn.close() 

def update_connections_time_zone(**kwargs):
    if kwargs['setting'] == 'TIME_ZONE':
        # Reset process time zone
        if hasattr(time, 'tzset'):
            if kwargs['value']:
                os.environ['TZ'] = kwargs['value']
            else:
                os.environ.pop('TZ', None)
            time.tzset()

        # Reset local time zone cache
        timezone.get_default_timezone.cache_clear()

    # Reset the database connections' time zone
    if kwargs['setting'] in {'TIME_ZONE', 'USE_TZ'}:
        for conn in connections.all():
            try:
                del conn.timezone
            except AttributeError:
                pass
            try:
                del conn.timezone_name
            except AttributeError:
                pass
            conn.ensure_timezone() 

def update_connections_time_zone(**kwargs):
    if kwargs['setting'] == 'TIME_ZONE':
        # Reset process time zone
        if hasattr(time, 'tzset'):
            if kwargs['value']:
                os.environ['TZ'] = kwargs['value']
            else:
                os.environ.pop('TZ', None)
            time.tzset()

        # Reset local time zone cache
        timezone.get_default_timezone.cache_clear()

    # Reset the database connections' time zone
    if kwargs['setting'] in {'TIME_ZONE', 'USE_TZ'}:
        for conn in connections.all():
            try:
                del conn.timezone
            except AttributeError:
                pass
            try:
                del conn.timezone_name
            except AttributeError:
                pass
            conn.ensure_timezone() 

def update_connections_time_zone(**kwargs):
    if kwargs['setting'] == 'TIME_ZONE':
        # Reset process time zone
        if hasattr(time, 'tzset'):
            if kwargs['value']:
                os.environ['TZ'] = kwargs['value']
            else:
                os.environ.pop('TZ', None)
            time.tzset()

        # Reset local time zone cache
        timezone.get_default_timezone.cache_clear()

    # Reset the database connections' time zone
    if kwargs['setting'] in {'TIME_ZONE', 'USE_TZ'}:
        for conn in connections.all():
            try:
                del conn.timezone
            except AttributeError:
                pass
            try:
                del conn.timezone_name
            except AttributeError:
                pass
            conn.ensure_timezone() 

def ensure_sql_instrumented():
    global sql_instrumented
    if sql_instrumented:
        return
    sql_instrumented = True

    if django.VERSION >= (2, 0):
        for connection in connections.all():
            install_db_execute_hook(connection=connection)
        connection_created.connect(install_db_execute_hook)
        logger.debug("Installed DB connection created signal handler")
    else:

        CursorWrapper.execute = execute_wrapper(CursorWrapper.execute)
        CursorWrapper.executemany = executemany_wrapper(CursorWrapper.executemany)

        logger.debug("Monkey patched SQL") 

def _post_teardown(self):
        """Performs any post-test things. This includes:

        * Flushing the contents of the database, to leave a clean slate. If
          the class has an 'available_apps' attribute, post_migrate isn't fired.
        * Force-closing the connection, so the next test gets a clean cursor.
        """
        try:
            self._fixture_teardown()
            super(TransactionTestCase, self)._post_teardown()
            if self._should_reload_connections():
                # Some DB cursors include SQL statements as part of cursor
                # creation. If you have a test that does a rollback, the effect
                # of these statements is lost, which can affect the operation of
                # tests (e.g., losing a timezone setting causing objects to be
                # created with the wrong time). To make sure this doesn't
                # happen, get a clean connection at the start of every test.
                for conn in connections.all():
                    conn.close()
        finally:
            if self.available_apps is not None:
                apps.unset_available_apps()
                setting_changed.send(sender=settings._wrapped.__class__,
                                     setting='INSTALLED_APPS',
                                     value=settings.INSTALLED_APPS,
                                     enter=False) 

def enable_instrumentation(self):
        # This is thread-safe because database connections are thread-local.
        for connection in connections.all():
            wrap_cursor(connection, self) 

def _tearDownClassInternal(cls):
        # There may not be a 'server_thread' attribute if setUpClass() for some
        # reasons has raised an exception.
        if hasattr(cls, 'server_thread'):
            # Terminate the live server's thread
            cls.server_thread.terminate()
            cls.server_thread.join()

        # Restore sqlite in-memory database connections' non-shareability
        for conn in connections.all():
            if conn.vendor == 'sqlite' and conn.is_in_memory_db(conn.settings_dict['NAME']):
                conn.allow_thread_sharing = False 

def disable_instrumentation(self):
        for connection in connections.all():
            unwrap_cursor(connection) 

def __mmc_get_queries(self, queries=0):
        for db in connections.all():
            queries += len(db.queries)
        return queries 

def get_debug_promise(self):
        if not self.debug_promise:
            self.debug_promise = Promise.all(self.promises)
            self.promises = []
        return self.debug_promise.then(self.on_resolve_all_promises) 

def skipUnlessDBFeature(*features):
    """
    Skip a test unless a database has all the named features.
    """
    return _deferredSkip(
        lambda: not all(getattr(connection.features, feature, False) for feature in features),
        "Database doesn't support feature(s): %s" % ", ".join(features)
    ) 

def connections_support_transactions():
    """
    Returns True if all connections support transactions.
    """
    return all(conn.features.supports_transactions
               for conn in connections.all()) 

def skipUnlessDBFeature(*features):
    """
    Skip a test unless a database has all the named features.
    """
    return _deferredSkip(
        lambda: not all(getattr(connection.features, feature, False) for feature in features),
        "Database doesn't support feature(s): %s" % ", ".join(features)
    ) 

def _databases_names(cls, include_mirrors=True):
        # If the test case has a multi_db=True flag, act on all databases,
        # including mirrors or not. Otherwise, just on the default DB.
        if getattr(cls, 'multi_db', False):
            return [alias for alias in connections
                    if include_mirrors or not connections[alias].settings_dict['TEST']['MIRROR']]
        else:
            return [DEFAULT_DB_ALIAS] 

def update_connections_time_zone(**kwargs):
    if kwargs['setting'] == 'TIME_ZONE':
        # Reset process time zone
        if hasattr(time, 'tzset'):
            if kwargs['value']:
                os.environ['TZ'] = kwargs['value']
            else:
                os.environ.pop('TZ', None)
            time.tzset()

        # Reset local time zone cache
        timezone.get_default_timezone.cache_clear()

    # Reset the database connections' time zone
    if kwargs['setting'] in {'TIME_ZONE', 'USE_TZ'}:
        for conn in connections.all():
            try:
                del conn.timezone
            except AttributeError:
                pass
            try:
                del conn.timezone_name
            except AttributeError:
                pass
            tz_sql = conn.ops.set_time_zone_sql()
            if tz_sql:
                with conn.cursor() as cursor:
                    cursor.execute(tz_sql, [conn.timezone_name]) 

def tearDownClass(cls):
        # There may not be a 'server_thread' attribute if setUpClass() for some
        # reasons has raised an exception.
        if hasattr(cls, 'server_thread'):
            # Terminate the live server's thread
            cls.server_thread.join()

        # Restore sqlite connections' non-sharability
        for conn in connections.all():
            if (conn.settings_dict['ENGINE'].rsplit('.', 1)[-1] in ('sqlite3', 'spatialite')
                and conn.settings_dict['NAME'] == ':memory:'):
                conn.allow_thread_sharing = False

        super(LiveServerTestCase, cls).tearDownClass() 

def _fixture_teardown(self):
        # Roll back any pending transactions in order to avoid a deadlock
        # during flush when TEST_MIRROR is used (#18984).
        for conn in connections.all():
            conn.rollback_unless_managed()

        for db in self._databases_names(include_mirrors=False):
            call_command('flush', verbosity=0, interactive=False, database=db,
                         skip_validation=True, reset_sequences=False) 

def _databases_names(self, include_mirrors=True):
        # If the test case has a multi_db=True flag, act on all databases,
        # including mirrors or not. Otherwise, just on the default DB.
        if getattr(self, 'multi_db', False):
            return [alias for alias in connections
                    if include_mirrors or not connections[alias].settings_dict['TEST_MIRROR']]
        else:
            return [DEFAULT_DB_ALIAS] 

def update_connections_time_zone(**kwargs):
    if kwargs['setting'] == 'TIME_ZONE':
        # Reset process time zone
        if hasattr(time, 'tzset'):
            if kwargs['value']:
                os.environ['TZ'] = kwargs['value']
            else:
                os.environ.pop('TZ', None)
            time.tzset()

        # Reset local time zone cache
        timezone._localtime = None

    # Reset the database connections' time zone
    if kwargs['setting'] == 'USE_TZ' and settings.TIME_ZONE != 'UTC':
        USE_TZ, TIME_ZONE = kwargs['value'], settings.TIME_ZONE
    elif kwargs['setting'] == 'TIME_ZONE' and not settings.USE_TZ:
        USE_TZ, TIME_ZONE = settings.USE_TZ, kwargs['value']
    else:
        # no need to change the database connnections' time zones
        return
    tz = 'UTC' if USE_TZ else TIME_ZONE
    for conn in connections.all():
        conn.settings_dict['TIME_ZONE'] = tz
        tz_sql = conn.ops.set_time_zone_sql()
        if tz_sql:
            conn.cursor().execute(tz_sql, [tz]) 

def patch_db():
    for conn in connections.all():
        module = importlib.import_module(conn.__module__)
        _patch_conn(getattr(module, conn.__class__.__name__)) 

def _tearDownClassInternal(cls):
        # There may not be a 'server_thread' attribute if setUpClass() for some
        # reasons has raised an exception.
        if hasattr(cls, 'server_thread'):
            # Terminate the live server's thread
            cls.server_thread.terminate()

        # Restore sqlite in-memory database connections' non-shareability
        for conn in connections.all():
            if conn.vendor == 'sqlite' and conn.is_in_memory_db():
                conn.allow_thread_sharing = False 

def setUpClass(cls):
        super(LiveServerTestCase, cls).setUpClass()
        connections_override = {}
        for conn in connections.all():
            # If using in-memory sqlite databases, pass the connections to
            # the server thread.
            if conn.vendor == 'sqlite' and conn.is_in_memory_db():
                # Explicitly enable thread-shareability for this connection
                conn.allow_thread_sharing = True
                connections_override[conn.alias] = conn

        cls._live_server_modified_settings = modify_settings(
            ALLOWED_HOSTS={'append': cls.host},
        )
        cls._live_server_modified_settings.enable()
        cls.server_thread = cls._create_server_thread(connections_override)
        cls.server_thread.daemon = True
        cls.server_thread.start()

        # Wait for the live server to be ready
        cls.server_thread.is_ready.wait()
        if cls.server_thread.error:
            # Clean up behind ourselves, since tearDownClass won't get called in
            # case of errors.
            cls._tearDownClassInternal()
            raise cls.server_thread.error 

def connections_support_transactions():
    """
    Returns True if all connections support transactions.
    """
    return all(conn.features.supports_transactions
               for conn in connections.all())