使用 Node 操作 Amazon DynamoDB 資料庫

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建立專案

建立專案。

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mkdir dynamodb-node-example
cd dynamodb-node-example

初始化專案。

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npm init

修改 package.json 檔。

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{
  "type": "module",
  ...
}

安裝依賴套件。

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npm i @aws-sdk/client-dynamodb

建立 examples/create-table.js 檔。

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import { CreateTableCommand, DynamoDBClient } from '@aws-sdk/client-dynamodb';

const client = new DynamoDBClient({
  endpoint: 'http://localhost:8000',
});

export const createTable = async () => {
  const command = new CreateTableCommand({
    TableName: "Drinks",
    AttributeDefinitions: [
      {
        AttributeName: "DrinkName",
        AttributeType: "S",
      },
    ],
    KeySchema: [
      {
        AttributeName: "DrinkName",
        KeyType: "HASH",
      },
    ],
    ProvisionedThroughput: {
      ReadCapacityUnits: 1,
      WriteCapacityUnits: 1,
    },
  });
  const response = await client.send(command);
  return response;
}

建立 examples/list-tables.js 檔。

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import { DynamoDBClient, ListTablesCommand } from '@aws-sdk/client-dynamodb';

const client = new DynamoDBClient({
  endpoint: 'http://localhost:8000',
});

export const listTables = async () => {
  const command = new ListTablesCommand({});
  const response = await client.send(command);
  console.log(response.TableNames.join('\n'));
  return response;
};

建立 examples/delete-table.js 檔。

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import { DeleteTableCommand, DynamoDBClient } from '@aws-sdk/client-dynamodb';

const client = new DynamoDBClient({
  endpoint: 'http://localhost:8000',
});

export const deleteTables = async () => {
  const command = new DeleteTableCommand({
    TableName: "Drinks",
  });
  const response = await client.send(command);
  return response;
};

建立 index.js 檔。

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import { createTable } from './examples/create-table.js';
import { deleteTables } from './examples/delete-table.js';
import { listTables } from './examples/list-tables.js';

await createTable();
await listTables();
await deleteTables();

執行腳本。

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aws-vault exec your-profile node index.js

輸出如下：

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Drinks

單元測試

新增 test/connect-handler.test.ts 檔。

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import { DynamoDBDocumentClient, PutCommand } from '@aws-sdk/lib-dynamodb';
import { mockClient } from 'aws-sdk-client-mock';
import { handler } from '../lambda/connect-handler';

const ddbMock = mockClient(DynamoDBDocumentClient);

beforeEach(() => {
  ddbMock.reset();
});

test('connect handler', async () => {
  const event = {
    requestContext: {
      connectionId: 'test',
    },
  };
  const result = await handler(event as any, {} as any, {} as any) as any;
  expect(result.statusCode as Number).toEqual(200);
  expect(ddbMock.calls()).toHaveLength(1);
  expect(ddbMock.commandCalls(PutCommand)[0].args[0].input).toEqual({
    TableName: process.env.TABLE_NAME,
    Item: {
      connectionId: 'test',
    },
  });
});

新增 test/disconnect-handler.test.ts 檔。

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import { DeleteCommand, DynamoDBDocumentClient } from '@aws-sdk/lib-dynamodb';
import { mockClient } from 'aws-sdk-client-mock';
import { handler } from '../lambda/disconnect-handler';

const ddbMock = mockClient(DynamoDBDocumentClient);

beforeEach(() => {
  ddbMock.reset();
});

test('disconnect handler', async () => {
  const event = {
    requestContext: {
      connectionId: 'test',
    },
  };
  const result = await handler(event as any, {} as any, {} as any) as any;
  expect(result.statusCode as Number).toEqual(200);
  expect(ddbMock.calls()).toHaveLength(1);
  expect(ddbMock.commandCalls(DeleteCommand)[0].args[0].input).toEqual({
    TableName: process.env.TABLE_NAME,
    Key: {
      connectionId: 'test',
    },
  });
});

執行測試。

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npm run test

程式碼

參考資料