Schritt 2: Testen Sie die Konnektivität zum Ledger

Wichtig

Hinweis zum Ende des Supports: Bestandskunden können Amazon QLDB bis zum Ende des Supports am 31.07.2025 nutzen. Weitere Informationen finden Sie unter Migrieren eines Amazon QLDB Ledgers zu Amazon Aurora SQL Postgre.

In diesem Schritt überprüfen Sie, ob Sie über den Transaktionsdatenendpunkt eine Verbindung zum vehicle-registration Ledger in Amazon QLDB herstellen können. API

So testen Sie die Verbindung zum Ledger

1. Verwenden Sie das folgende Programm (ConnectToLedger.ts), um eine Datensitzungsverbindung mit dem Ledger vehicle-registration zu erstellen.

   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();
   }

   Anmerkung

   Um Datentransaktionen in Ihrem Ledger auszuführen, müssen Sie ein QLDB Treiberobjekt erstellen, um eine Verbindung zu einem bestimmten Ledger herzustellen. Dies ist ein anderes Client-Objekt als das qldbClient-Objekt, das Sie im vorherigen Schritt zum Erstellen des Ledgers verwendet haben. Dieser vorherige Client wird nur verwendet, um die in der aufgeführten API Verwaltungsvorgänge auszuführen. QLDBAPIAmazon-Referenz

2. Geben Sie den folgenden Befehl ein, um das transpilierte Programm auszuführen.

   node dist/ConnectToLedger.js

Fahren Sie zum Erstellen von Tabellen im vehicle-registration-Ledger mit Schritt 3: Erstellen Sie Tabellen, Indizes und Beispieldaten fort.