ステップ 2: 台帳への接続をテストする

重要

サポート終了通知: 既存のお客様は、07/31/2025 のサポート終了QLDBまで Amazon を使用できます。詳細については、「Amazon Ledger QLDB を Amazon Aurora Postgre に移行するSQL」を参照してください。

このステップでは、トランザクションデータAPIエンドポイントQLDBを使用して Amazon のvehicle-registration台帳に接続できることを確認します。

台帳への接続をテストするには

1. 次のプログラム (ConnectToLedger.ts) を使用して、vehicle-registration 台帳へのデータセッション接続を作成します。

   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.
    */
   
   import { QldbDriver, RetryConfig  } from "amazon-qldb-driver-nodejs";
   import { ClientConfiguration } from "aws-sdk/clients/qldbsession";
   
   import { LEDGER_NAME } from "./qldb/Constants";
   import { error, log } from "./qldb/LogUtil";
   
   const qldbDriver: QldbDriver = createQldbDriver();
   
   /**
    * Create a driver for creating sessions.
    * @param ledgerName The name of the ledger to create the driver on.
    * @param serviceConfigurationOptions The configurations for the AWS SDK client that the driver uses.
    * @returns The driver for creating sessions.
    */
   export function createQldbDriver(
       ledgerName: string = LEDGER_NAME,
       serviceConfigurationOptions: ClientConfiguration = {}
   ): QldbDriver {
       const retryLimit = 4;
       const maxConcurrentTransactions = 10;
       //Use driver's default backoff function (and hence, no second parameter provided to RetryConfig)
       const retryConfig: RetryConfig = new RetryConfig(retryLimit);
       const qldbDriver: QldbDriver = new QldbDriver(ledgerName, serviceConfigurationOptions, maxConcurrentTransactions, retryConfig);
       return qldbDriver;
   }
   
   export function getQldbDriver(): QldbDriver {
       return qldbDriver;
   }
   
   /**
    * Connect to a session for a given ledger using default settings.
    * @returns Promise which fulfills with void.
    */
   const main = async function(): Promise<void> {
       try {
           log("Listing table names...");
           const tableNames: string[] = await qldbDriver.getTableNames();
           tableNames.forEach((tableName: string): void => {
               log(tableName);
           });
       } catch (e) {
           error(`Unable to create session: ${e}`);
       }
   }
   
   if (require.main === module) {
       main();
   }

   1.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.
    */
   
   import { QldbDriver  } from "amazon-qldb-driver-nodejs";
   import { ClientConfiguration } from "aws-sdk/clients/qldbsession";
   
   import { LEDGER_NAME } from "./qldb/Constants";
   import { error, log } from "./qldb/LogUtil";
   
   const qldbDriver: QldbDriver = createQldbDriver();
   
   /**
    * Create a driver for creating sessions.
    * @param ledgerName The name of the ledger to create the driver on.
    * @param serviceConfigurationOptions The configurations for the AWS SDK client that the driver uses.
    * @returns The driver for creating sessions.
    */
   export function createQldbDriver(
       ledgerName: string = LEDGER_NAME,
       serviceConfigurationOptions: ClientConfiguration = {}
   ): QldbDriver {
       const qldbDriver: QldbDriver = new QldbDriver(ledgerName, serviceConfigurationOptions);
       return qldbDriver;
   }
   
   export function getQldbDriver(): QldbDriver {
       return qldbDriver;
   }
   
   /**
    * Connect to a session for a given ledger using default settings.
    * @returns Promise which fulfills with void.
    */
   var main = async function(): Promise<void> {
       try {
           log("Listing table names...");
           const tableNames: string[] = await qldbDriver.getTableNames();
           tableNames.forEach((tableName: string): void => {
               log(tableName);
           });
       } catch (e) {
           error(`Unable to create session: ${e}`);
       } 
   }
   
   if (require.main === module) {
       main();
   }

   注記

   台帳でデータトランザクションを実行するには、指定された台帳に接続するQLDBドライバーオブジェクトを作成する必要があります。これは、前のステップで台帳の作成に使用した qldbClient オブジェクトとは異なるクライアントオブジェクトです。その以前のクライアントは、「」に記載されている管理APIオペレーションの実行にのみ使用されますAmazon QLDBAPIリファレンス。

2. トランスパイルされたプログラムを実行するには、次のコマンドを入力します。

   node dist/ConnectToLedger.js

vehicle-registration 台帳にテーブルを作成するには、「ステップ 3: テーブル、インデックス、およびサンプルデータを作成する」に進みます。