步驟 2：測試與分類帳的連線

重要

支援結束通知：現有客戶將能夠使用 Amazon，QLDB直到 2025 年 7 月 31 日終止支援為止。有關更多詳細信息，請參閱將 Amazon QLDB 分類帳遷移到 Amazon Aurora 郵政. SQL

在此步驟中，您確認可以QLDB使用交易資料API端點連接到 Amazon 中的vehicle-registration分類帳。

若要測試與分類帳的連線

使用下列程式 (connect_to_ledger.py) 建立與vehicle-registration分類帳的資料階段作業連線。

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 logging import basicConfig, getLogger, INFO

from botocore.exceptions import ClientError

from pyqldb.driver.qldb_driver import QldbDriver
from pyqldbsamples.constants import Constants

logger = getLogger(__name__)
basicConfig(level=INFO)


def create_qldb_driver(ledger_name=Constants.LEDGER_NAME, region_name=None, endpoint_url=None, boto3_session=None):
    """
    Create a QLDB driver for executing transactions.

    :type ledger_name: str
    :param ledger_name: The QLDB ledger name.

    :type region_name: str
    :param region_name: See [1].

    :type endpoint_url: str
    :param endpoint_url: See [1].

    :type boto3_session: :py:class:`boto3.session.Session`
    :param boto3_session: The boto3 session to create the client with (see [1]).

    :rtype: :py:class:`pyqldb.driver.qldb_driver.QldbDriver`
    :return: A QLDB driver object.

    [1]: `Boto3 Session.client Reference <https://boto3.amazonaws.com/v1/documentation/api/latest/reference/core/session.html#boto3.session.Session.client>`.
    """
    qldb_driver = QldbDriver(ledger_name=ledger_name, region_name=region_name, endpoint_url=endpoint_url,
                             boto3_session=boto3_session)
    return qldb_driver


def main(ledger_name=Constants.LEDGER_NAME):
    """
    Connect to a given ledger using default settings.
    """
    try:
        with create_qldb_driver(ledger_name) as driver:
            logger.info('Listing table names ')
            for table in driver.list_tables():
                logger.info(table)
    except ClientError as ce:
        logger.exception('Unable to list tables.')
        raise ce


if __name__ == '__main__':
    main()

注意

若要在分類帳上執行資料交易，您必須建立QLDB驅動程式物件以連線至特定分類帳。這與您在上一個步驟中用來建立分類帳的qldb_client物件不同的用戶端物件。先前的用戶端僅用於執行中列出的管理API作業Amazon QLDB API 參考。
建立此動因物件時，您必須指定分類帳名稱。

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 logging import basicConfig, getLogger, INFO

from botocore.exceptions import ClientError

from pyqldb.driver.pooled_qldb_driver import PooledQldbDriver
from pyqldbsamples.constants import Constants

logger = getLogger(__name__)
basicConfig(level=INFO)


def create_qldb_driver(ledger_name=Constants.LEDGER_NAME, region_name=None, endpoint_url=None, boto3_session=None):
    """
    Create a QLDB driver for creating sessions.

    :type ledger_name: str
    :param ledger_name: The QLDB ledger name.

    :type region_name: str
    :param region_name: See [1].

    :type endpoint_url: str
    :param endpoint_url: See [1].

    :type boto3_session: :py:class:`boto3.session.Session`
    :param boto3_session: The boto3 session to create the client with (see [1]).

    :rtype: :py:class:`pyqldb.driver.pooled_qldb_driver.PooledQldbDriver`
    :return: A pooled QLDB driver object.

    [1]: `Boto3 Session.client Reference <https://boto3.amazonaws.com/v1/documentation/api/latest/reference/core/session.html#boto3.session.Session.client>`.
    """
    qldb_driver = PooledQldbDriver(ledger_name=ledger_name, region_name=region_name, endpoint_url=endpoint_url,
                                   boto3_session=boto3_session)
    return qldb_driver


def create_qldb_session():
    """
    Retrieve a QLDB session object.

    :rtype: :py:class:`pyqldb.session.pooled_qldb_session.PooledQldbSession`
    :return: A pooled QLDB session object.
    """
    qldb_session = pooled_qldb_driver.get_session()
    return qldb_session


pooled_qldb_driver = create_qldb_driver()


if __name__ == '__main__':
    """
    Connect to a session for a given ledger using default settings.
    """
    try:
        qldb_session = create_qldb_session()
        logger.info('Listing table names ')
        for table in qldb_session.list_tables():
            logger.info(table)
    except ClientError:
        logger.exception('Unable to create session.')

注意

若要在分類帳上執行資料交易，您必須建立QLDB驅動程式物件以連線至特定分類帳。這與您在上一個步驟中用來建立分類帳的qldb_client物件不同的用戶端物件。先前的用戶端僅用於執行中列出的管理API作業Amazon QLDB API 參考。
首先，建立集區的QLDB驅動程式物件。建立此動因時，您必須指定分類帳名稱。
然後，您可以從這個集區的驅動程式物件建立工作階段。

若要執行程式，請輸入下列命令。
```
python connect_to_ledger.py
```

若要在vehicle-registration分類帳中建立表格，請繼續執行步驟 3：建立資料表、索引和範例資料。

您的瀏覽器已停用或無法使用 Javascript。

您必須啟用 Javascript，才能使用 AWS 文件。請參閱您的瀏覽器說明頁以取得說明。

文件慣用形式

步驟 1：建立新分類帳

步驟 3：建立資料表、索引和範例資料