Using DynamoDB

DynamoDB is a fully managed NoSQL database service offered by AWS. It's designed for high-performance, low-latency applications that need to scale seamlessly.

Adding your DynamoDB table to CDK

To create your DynamoDB table, you need to define a CDK construct for it.

Our recommendation is to use the Table construct from aws-cdk-lib/aws-dynamodb.

import { Stack, StackProps } from 'aws-cdk-lib';
import { Construct } from 'constructs';
import { NodejsFunction, OutputFormat } from 'aws-cdk-lib/aws-lambda-nodejs';
import { AttributeType, BillingMode, Table } from "aws-cdk-lib/aws-dynamodb";

export class AppStack extends Stack {
  constructor(scope: Construct, id: string, props?: StackProps) {
    super(scope, id, props);

    // const myLambdaFunction = ...

    const myTable = new Table(this, id, {
      partitionKey: { name: "id", type: AttributeType.STRING },
      billingMode: BillingMode.PAY_PER_REQUEST
    });

    // since the table name is created dynamically, 
    // you may want to pass it to your lambda as environment variable:
    // myLambdaFunction.addEnvironment("MY_TABLE_NAME", myTable.tableName);
  }
}

Recommended settings for this construct can be found on our CDK snippet page.

Writing a repository

To interact with DynamoDB, we recommend using @aws-sdk/lib-dynamodb. This library simplifies the process by removing the need to manually marshal and unmarshal DynamoDB attribute values.

If you prefer, you can even use the default repository implementation from @backpack/amazon-dynamodb, which streamlines common DynamoDB operations:

import { DynamoDBClient } from "@aws-sdk/client-dynamodb";
import { DynamoDBDocumentClient } from "@aws-sdk/lib-dynamodb";
import { DynamoDbRepository } from "@backpack/amazon-dynamodb";

// Create a client
const client = DynamoDBDocumentClient.from(new DynamoDBClient());

// Define a repository
const booksRepository = new DynamoDbRepository<Book>(
  client,
  { tableName: 'Books' }
);

// Retrieve an item by ID
const book = await booksRepository.getItemById({ isbn: "9789027439642" });

Check out @backpack/amazon-dynamodb to learn more. Or have a look at the Bookstore REST API demo.