ステップ 5: 台帳内のドキュメントを変更する

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。

これで、操作するデータを取得できたので、Amazon のvehicle-registration台帳のドキュメントに変更を加えることができますQLDB。このステップでは、次のコード例は、データ操作言語 (DML) ステートメントを実行する方法を示しています。これらのステートメントは、ある車両の主所有者を更新し、別の車両に第二所有者を追加します。

ドキュメントに変更を加えるには

次のプログラム (TransferVehicleOwnership.ts) を使用して、台帳内の VIN1N4AL11D75C109151で車両の主要所有者を更新します。


/*
 * 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, Result, TransactionExecutor } from "amazon-qldb-driver-nodejs";
import { dom } from "ion-js";

import { getQldbDriver } from "./ConnectToLedger";
import { PERSON, VEHICLE } from "./model/SampleData";
import { PERSON_TABLE_NAME } from "./qldb/Constants";
import { error, log } from "./qldb/LogUtil";
import { getDocumentId } from "./qldb/Util";

/**
 * Query a driver's information using the given ID.
 * @param txn The {@linkcode TransactionExecutor} for lambda execute.
 * @param documentId The unique ID of a document in the Person table.
 * @returns Promise which fulfills with an Ion value containing the person.
 */
export async function findPersonFromDocumentId(txn: TransactionExecutor, documentId: string): Promise<dom.Value> {
    const query: string = "SELECT p.* FROM Person AS p BY pid WHERE pid = ?";

    let personId: dom.Value;
    await txn.execute(query, documentId).then((result: Result) => {
        const resultList: dom.Value[] = result.getResultList();
        if (resultList.length === 0) {
            throw new Error(`Unable to find person with ID: ${documentId}.`);
        }
        personId = resultList[0];
    });
    return personId;
}

/**
 * Find the primary owner for the given VIN.
 * @param txn The {@linkcode TransactionExecutor} for lambda execute.
 * @param vin The VIN to find primary owner for.
 * @returns Promise which fulfills with an Ion value containing the primary owner.
 */
export async function findPrimaryOwnerForVehicle(txn: TransactionExecutor, vin: string): Promise<dom.Value> {
    log(`Finding primary owner for vehicle with VIN: ${vin}`);
    const query: string = "SELECT Owners.PrimaryOwner.PersonId FROM VehicleRegistration AS v WHERE v.VIN = ?";

    let documentId: string = undefined;
    await txn.execute(query, vin).then((result: Result) => {
        const resultList: dom.Value[] = result.getResultList();
        if (resultList.length === 0) {
            throw new Error(`Unable to retrieve document ID using ${vin}.`);
        }
        const PersonIdValue: dom.Value = resultList[0].get("PersonId");
        if (PersonIdValue === null) {
            throw new Error(`Expected field name PersonId not found.`);
        }
        documentId = PersonIdValue.stringValue();
    });
    return findPersonFromDocumentId(txn, documentId);
}

/**
 * Update the primary owner for a vehicle using the given VIN.
 * @param txn The {@linkcode TransactionExecutor} for lambda execute.
 * @param vin The VIN for the vehicle to operate on.
 * @param documentId New PersonId for the primary owner.
 * @returns Promise which fulfills with void.
 */
async function updateVehicleRegistration(txn: TransactionExecutor, vin: string, documentId: string): Promise<void> {
    const statement: string = "UPDATE VehicleRegistration AS r SET r.Owners.PrimaryOwner.PersonId = ? WHERE r.VIN = ?";

    log(`Updating the primary owner for vehicle with VIN: ${vin}...`);
    await txn.execute(statement, documentId, vin).then((result: Result) => {
        const resultList: dom.Value[] = result.getResultList();
        if (resultList.length === 0) {
            throw new Error("Unable to transfer vehicle, could not find registration.");
        }
        log(`Successfully transferred vehicle with VIN ${vin} to new owner.`);
    });
}

/**
 * Validate the current owner of the given vehicle and transfer its ownership to a new owner in a single transaction.
 * @param txn The {@linkcode TransactionExecutor} for lambda execute.
 * @param vin The VIN of the vehicle to transfer ownership of.
 * @param currentOwner The GovId of the current owner of the vehicle.
 * @param newOwner The GovId of the new owner of the vehicle.
 */
export async function validateAndUpdateRegistration(
    txn: TransactionExecutor,
    vin: string,
    currentOwner: string,
    newOwner: string
): Promise<void> {
    const primaryOwner: dom.Value = await findPrimaryOwnerForVehicle(txn, vin);
    const govIdValue: dom.Value = primaryOwner.get("GovId");
    if (govIdValue !== null && govIdValue.stringValue() !== currentOwner) {
        log("Incorrect primary owner identified for vehicle, unable to transfer.");
    }
    else {
        const documentId: string = await getDocumentId(txn, PERSON_TABLE_NAME, "GovId", newOwner);
        await updateVehicleRegistration(txn, vin, documentId);
        log("Successfully transferred vehicle ownership!");
    }
}

/**
 * Find primary owner for a particular vehicle's VIN.
 * Transfer to another primary owner for a particular vehicle's VIN.
 * @returns Promise which fulfills with void.
 */
const main = async function(): Promise<void> {
    try {
        const qldbDriver: QldbDriver = getQldbDriver();

        const vin: string = VEHICLE[0].VIN;
        const previousOwnerGovId: string = PERSON[0].GovId;
        const newPrimaryOwnerGovId: string = PERSON[1].GovId;

        await qldbDriver.executeLambda(async (txn: TransactionExecutor) => {
            await validateAndUpdateRegistration(txn, vin, previousOwnerGovId,  newPrimaryOwnerGovId);
        });
    } catch (e) {
        error(`Unable to connect and run queries: ${e}`);
    }
}

if (require.main === module) {
    main();
}

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/TransferVehicleOwnership.js
```

次のプログラム (AddSecondaryOwner.ts) を使用して、台帳VINKM8SRDHF6EU074761のでセカンダリ所有者を車両に追加します。


/*
 * 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, Result, TransactionExecutor } from "amazon-qldb-driver-nodejs";
import { dom } from "ion-js";

import { getQldbDriver } from "./ConnectToLedger";
import { PERSON, VEHICLE_REGISTRATION } from "./model/SampleData";
import { PERSON_TABLE_NAME } from "./qldb/Constants";
import { error, log } from "./qldb/LogUtil";
import { getDocumentId } from "./qldb/Util";
import { prettyPrintResultList } from "./ScanTable";

/**
 * Add a secondary owner into 'VehicleRegistration' table for a particular VIN.
 * @param txn The {@linkcode TransactionExecutor} for lambda execute.
 * @param vin VIN of the vehicle to query.
 * @param secondaryOwnerId The secondary owner's person ID.
 * @returns Promise which fulfills with void.
 */
export async function addSecondaryOwner(
    txn: TransactionExecutor, 
    vin: string, 
    secondaryOwnerId: string
): Promise<void> {
    log(`Inserting secondary owner for vehicle with VIN: ${vin}`);
    const query: string =
        `FROM VehicleRegistration AS v WHERE v.VIN = ? INSERT INTO v.Owners.SecondaryOwners VALUE ?`;

    const personToInsert = {PersonId: secondaryOwnerId};
    await txn.execute(query, vin, personToInsert).then(async (result: Result) => {
        const resultList: dom.Value[] = result.getResultList();
        log("VehicleRegistration Document IDs which had secondary owners added: ");
        prettyPrintResultList(resultList);
    });
}

/**
 * Query for a document ID with a government ID.
 * @param txn The {@linkcode TransactionExecutor} for lambda execute.
 * @param governmentId The government ID to query with.
 * @returns Promise which fulfills with the document ID as a string.
 */
export async function getDocumentIdByGovId(txn: TransactionExecutor, governmentId: string): Promise<string> {
    const documentId: string = await getDocumentId(txn, PERSON_TABLE_NAME, "GovId", governmentId);
    return documentId;
}

/**
 * Check whether a driver has already been registered for the given VIN.
 * @param txn The {@linkcode TransactionExecutor} for lambda execute.
 * @param vin VIN of the vehicle to query.
 * @param secondaryOwnerId The secondary owner's person ID.
 * @returns Promise which fulfills with a boolean.
 */
export async function isSecondaryOwnerForVehicle(
    txn: TransactionExecutor,
    vin: string,
    secondaryOwnerId: string
): Promise<boolean> {
    log(`Finding secondary owners for vehicle with VIN: ${vin}`);
    const query: string = "SELECT Owners.SecondaryOwners FROM VehicleRegistration AS v WHERE v.VIN = ?";

    let doesExist: boolean = false;

    await txn.execute(query, vin).then((result: Result) => {
        const resultList: dom.Value[] = result.getResultList();

        resultList.forEach((value: dom.Value) => {
            const secondaryOwnersList: dom.Value[] = value.get("SecondaryOwners").elements();

            secondaryOwnersList.forEach((secondaryOwner) => {
                const personId: dom.Value = secondaryOwner.get("PersonId");
                if (personId !== null &&  personId.stringValue() === secondaryOwnerId) {
                    doesExist = true;
                }
            });
        });
    });
    return doesExist;
}

/**
 * Finds and adds secondary owners for a vehicle.
 * @returns Promise which fulfills with void.
 */
const main = async function(): Promise<void> {
    try {
        const qldbDriver: QldbDriver = getQldbDriver();
        const vin: string = VEHICLE_REGISTRATION[1].VIN;
        const govId: string = PERSON[0].GovId;

        await qldbDriver.executeLambda(async (txn: TransactionExecutor) => {
            const documentId: string = await getDocumentIdByGovId(txn, govId);

            if (await isSecondaryOwnerForVehicle(txn, vin, documentId)) {
                log(`Person with ID ${documentId} has already been added as a secondary owner of this vehicle.`);
            } else {
                await addSecondaryOwner(txn, vin, documentId);
            }
        });

        log("Secondary owners successfully updated.");
    } catch (e) {
        error(`Unable to add secondary owner: ${e}`);
    } 
}

if (require.main === module) {
    main();
}

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/AddSecondaryOwner.js
```

これらの変更を vehicle-registration 台帳で確認するには、「ステップ 6: ドキュメントのリビジョン履歴を表示する」を参照してください。

ブラウザで JavaScript が無効になっているか、使用できません。

AWS ドキュメントを使用するには、JavaScript を有効にする必要があります。手順については、使用するブラウザのヘルプページを参照してください。

ドキュメントの表記規則

ステップ 4: テーブルのクエリを実行する

ステップ 6: リビジョン履歴を表示する