Las traducciones son generadas a través de traducción automática. En caso de conflicto entre la traducción y la version original de inglés, prevalecerá la version en inglés. # Paso 6: ver el historial de revisiones de un documento **importante** Aviso de fin del soporte: los clientes actuales podrán utilizar Amazon QLDB hasta que finalice el soporte, el 31 de julio de 2025. Para obtener más información, consulte [Migración de un registro de Amazon QLDB a Amazon Aurora](https://aws.amazon.com/blogs/database/migrate-an-amazon-qldb-ledger-to-amazon-aurora-postgresql/) PostgreSQL. Tras modificar los datos de registro de un vehículo en el paso anterior, puede consultar el historial de todos sus propietarios registrados y cualquier otro campo actualizado. En este paso, consulta el historial de revisiones de un documento de la tabla `VehicleRegistration` del libro mayor `vehicle-registration`. **Para ver el historial de revisiones** 1. Utilice el siguiente programa (`query_history.py`) para consultar el historial de revisiones del documento `VehicleRegistration` con el VIN `1N4AL11D75C109151`. ------ #### [ 3.x ] ``` # Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved. # SPDX-License-Identifier: MIT-0 # # Permission is hereby granted, free of charge, to any person obtaining a copy of this # software and associated documentation files (the "Software"), to deal in the Software # without restriction, including without limitation the rights to use, copy, modify, # merge, publish, distribute, sublicense, and/or sell copies of the Software, and to # permit persons to whom the Software is furnished to do so. # # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, # INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A # PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT # HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE # SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. # # This code expects that you have AWS credentials setup per: # https://boto3.amazonaws.com/v1/documentation/api/latest/guide/quickstart.html from datetime import datetime, timedelta from logging import basicConfig, getLogger, INFO from pyqldbsamples.model.sample_data import print_result, get_document_ids, SampleData from pyqldbsamples.constants import Constants from pyqldbsamples.connect_to_ledger import create_qldb_driver logger = getLogger(__name__) basicConfig(level=INFO) def format_date_time(date_time): """ Format the given date time to a string. :type date_time: :py:class:`datetime.datetime` :param date_time: The date time to format. :rtype: str :return: The formatted date time. """ return date_time.strftime('`%Y-%m-%dT%H:%M:%S.%fZ`') def previous_primary_owners(driver, vin): """ Find previous primary owners for the given VIN in a single transaction. In this example, query the `VehicleRegistration` history table to find all previous primary owners for a VIN. :type driver: :py:class:`pyqldb.driver.qldb_driver.QldbDriver` :param driver: An instance of the QldbDriver class. :type vin: str :param vin: VIN to find previous primary owners for. """ person_ids = driver.execute_lambda(lambda executor: get_document_ids(executor, Constants.VEHICLE_REGISTRATION_TABLE_NAME, 'VIN', vin)) todays_date = datetime.utcnow() - timedelta(seconds=1) three_months_ago = todays_date - timedelta(days=90) query = 'SELECT data.Owners.PrimaryOwner, metadata.version FROM history({}, {}, {}) AS h WHERE h.metadata.id = ?'.\ format(Constants.VEHICLE_REGISTRATION_TABLE_NAME, format_date_time(three_months_ago), format_date_time(todays_date)) for ids in person_ids: logger.info("Querying the 'VehicleRegistration' table's history using VIN: {}.".format(vin)) cursor = driver.execute_lambda(lambda executor: executor.execute_statement(query, ids)) if not (print_result(cursor)) > 0: logger.info('No modification history found within the given time frame for document ID: {}'.format(ids)) def main(ledger_name=Constants.LEDGER_NAME): """ Query a table's history for a particular set of documents. """ try: with create_qldb_driver(ledger_name) as driver: vin = SampleData.VEHICLE_REGISTRATION[0]['VIN'] previous_primary_owners(driver, vin) logger.info('Successfully queried history.') except Exception as e: logger.exception('Unable to query history to find previous owners.') raise e if __name__ == '__main__': main() ``` ------ #### [ 2.x ] ``` # Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved. # SPDX-License-Identifier: MIT-0 # # Permission is hereby granted, free of charge, to any person obtaining a copy of this # software and associated documentation files (the "Software"), to deal in the Software # without restriction, including without limitation the rights to use, copy, modify, # merge, publish, distribute, sublicense, and/or sell copies of the Software, and to # permit persons to whom the Software is furnished to do so. # # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, # INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A # PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT # HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE # SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. # # This code expects that you have AWS credentials setup per: # https://boto3.amazonaws.com/v1/documentation/api/latest/guide/quickstart.html from datetime import datetime, timedelta from logging import basicConfig, getLogger, INFO from pyqldbsamples.model.sample_data import print_result, get_document_ids, SampleData from pyqldbsamples.constants import Constants from pyqldbsamples.connect_to_ledger import create_qldb_session logger = getLogger(__name__) basicConfig(level=INFO) def format_date_time(date_time): """ Format the given date time to a string. :type date_time: :py:class:`datetime.datetime` :param date_time: The date time to format. :rtype: str :return: The formatted date time. """ return date_time.strftime('`%Y-%m-%dT%H:%M:%S.%fZ`') def previous_primary_owners(transaction_executor, vin): """ Find previous primary owners for the given VIN in a single transaction. In this example, query the `VehicleRegistration` history table to find all previous primary owners for a VIN. :type transaction_executor: :py:class:`pyqldb.execution.executor.Executor` :param transaction_executor: An Executor object allowing for execution of statements within a transaction. :type vin: str :param vin: VIN to find previous primary owners for. """ person_ids = get_document_ids(transaction_executor, Constants.VEHICLE_REGISTRATION_TABLE_NAME, 'VIN', vin) todays_date = datetime.utcnow() - timedelta(seconds=1) three_months_ago = todays_date - timedelta(days=90) query = 'SELECT data.Owners.PrimaryOwner, metadata.version FROM history({}, {}, {}) AS h WHERE h.metadata.id = ?'.\ format(Constants.VEHICLE_REGISTRATION_TABLE_NAME, format_date_time(three_months_ago), format_date_time(todays_date)) for ids in person_ids: logger.info("Querying the 'VehicleRegistration' table's history using VIN: {}.".format(vin)) cursor = transaction_executor.execute_statement(query, ids) if not (print_result(cursor)) > 0: logger.info('No modification history found within the given time frame for document ID: {}'.format(ids)) if __name__ == '__main__': """ Query a table's history for a particular set of documents. """ try: with create_qldb_session() as session: vin = SampleData.VEHICLE_REGISTRATION[0]['VIN'] session.execute_lambda(lambda lambda_executor: previous_primary_owners(lambda_executor, vin), lambda retry_attempt: logger.info('Retrying due to OCC conflict...')) logger.info('Successfully queried history.') except Exception: logger.exception('Unable to query history to find previous owners.') ``` ------ **nota** Puede ver el historial de revisiones de un documento consultando la [Función de historial](working.history.md#working.history.function) integrada en la siguiente sintaxis. ``` SELECT * FROM history( table_name [, `start-time` [, `end-time` ] ] ) AS h [ WHERE h.metadata.id = 'id' ] ``` Tanto la *hora de inicio* como la hora de *finalización* son opcionales. Son valores literales de Amazon Ion que se pueden indicar con acentos graves (``...``). Para obtener más información, consulte [Consulta de Ion con PartiQL en Amazon QLDB](ql-reference.query.md). Como práctica recomendada, califique una consulta de historial con un intervalo de fechas (*hora de inicio* y *hora de finalización*) y un identificador de documento (`metadata.id`). QLDB procesa las consultas `SELECT` en las transacciones, que están sujetas a un [límite de tiempo de espera de las transacciones](limits.md#limits.fixed). El historial de QLDB se indexa por ID de documento y no se pueden crear índices de historial adicionales en este momento. Las consultas de historial que incluyen una hora de inicio y una hora de finalización se benefician de la calificación por intervalo de fechas. 1. Para ejecutar el programa, introduzca el siguiente comando. ``` python query_history.py ``` Para verificar criptográficamente la revisión de un documento en el libro mayor `vehicle-registration`, continúe con [Paso 7: verificar un documento en un libro mayor](getting-started.python.step-7.md).