Étape 6 : Afficher l'historique des révisions d'un document

Important

Avis de fin de support : les clients existants pourront utiliser Amazon QLDB jusqu'à la fin du support le 31 juillet 2025. Pour plus de détails, consultez Migrer un Amazon QLDB Ledger vers Amazon Aurora SQL Postgre.

Après avoir modifié les données d'immatriculation d'un véhicule à l'étape précédente, vous pouvez consulter l'historique de tous ses propriétaires enregistrés et tout autre champ mis à jour. Au cours de cette étape, vous recherchez l'historique des révisions d'un document dans le VehicleRegistration tableau de votre vehicle-registration grand livre.

Pour consulter l'historique des révisions

Utilisez le programme suivant (query_history.py) pour interroger l'historique des révisions du VehicleRegistration document avec VIN1N4AL11D75C109151.

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.')

Note

Vous pouvez consulter l'historique des révisions d'un document en interrogeant la syntaxe intégrée Fonction d'historique ci-dessous.
```
SELECT * FROM history( table_name [, `start-time` [, `end-time` ] ] ) AS h
[ WHERE h.metadata.id = 'id' ]
```
L'heure de début et l'heure de fin sont toutes deux facultatives. Ce sont des valeurs littérales d'Amazon Ion qui peuvent être indiquées par des backticks (). `...` Pour en savoir plus, veuillez consulter la section Interroger Ion avec PartiQL sur Amazon QLDB.
Il est recommandé de qualifier une requête d'historique à la fois par une plage de dates (heure de début et heure de fin) et par un identifiant de document (metadata.id). QLDBtraite les SELECT requêtes dans les transactions, qui sont soumises à un délai d'expiration des transactions.

QLDBl'historique est indexé par numéro de document, et vous ne pouvez pas créer d'index d'historique supplémentaire pour le moment. Les requêtes d'historique qui incluent une heure de début et une heure de fin bénéficient de la qualification par plage de dates.

Pour exécuter le programme, saisissez la commande suivante.
```
python query_history.py
```

Pour vérifier cryptographiquement une révision de document dans le vehicle-registration registre, passez à. Étape 7 : Vérifier un document dans un registre

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Conventions de rédaction

Étape 5 : Modifier les documents

Étape 7 : vérifier un document