FreeOpcUa / python-opcua

            return results, cont

    def new_historized_event(self, source_id, ev_fields, period):

        with self._lock:

            _c_new = self._conn.cursor()

            self._datachanges_period[source_id] = period

            self._event_fields[source_id] = ev_fields

            table = self._get_table_name(source_id)

            columns = self._get_event_columns(ev_fields)

            # create a table for the event which will store fields generated by the source object's events

            # note that _Timestamp is for SQL query, _EventTypeName is for debugging, be careful not to create event

            # properties with these names

            try:

                _c_new.execute('CREATE TABLE "{tn}" (_Id INTEGER PRIMARY KEY NOT NULL, '

                               '_Timestamp TIMESTAMP, '

                               '_EventTypeName TEXT, '

                               '{co})'.format(tn=table, co=columns))

            except sqlite3.Error as e:

                self.logger.info('Historizing SQL Table Creation Error for events from %s: %s', source_id, e)

            self._conn.commit()

    def save_event(self, event):

        with self._lock:

        self._conn = sqlite3.connect(self._db_file, detect_types=sqlite3.PARSE_DECLTYPES, check_same_thread=False)

    def new_historized_node(self, node_id, period, count=0):

        with self._lock:

            _c_new = self._conn.cursor()

            table = self._get_table_name(node_id)

            self._datachanges_period[node_id] = period, count

            # create a table for the node which will store attributes of the DataValue object

            # note: Value/VariantType TEXT is only for human reading, the actual data is stored in VariantBinary column

            try:

                _c_new.execute('CREATE TABLE "{tn}" (_Id INTEGER PRIMARY KEY NOT NULL,'

                               ' ServerTimestamp TIMESTAMP,'

                               ' SourceTimestamp TIMESTAMP,'

                               ' StatusCode INTEGER,'

                               ' Value TEXT,'

                               ' VariantType TEXT,'

                               ' VariantBinary BLOB)'.format(tn=table))

            except sqlite3.Error as e:

                self.logger.info('Historizing SQL Table Creation Error for %s: %s', node_id, e)

            self._conn.commit()

    def save_node_value(self, node_id, datavalue):

        with self._lock: