DynamoDB and Node.js - Complete Cheat Sheet

DynamoDB-and-Node.js

### Setup

const AWS = require("aws-sdk") // Or use `import` syntax for Typescript and newer ES versions

const dynamoDB = new AWS.DynamoDB({
  region: "us-east-1"
})

// Or

const documentClient = new AWS.DynamoDB.DocumentClient({
  region: "us-east-1"
})

## Get All Items / Scan in DynamoDB
dynamoDB
  .scan({
    TableName: "my-table",
  })
  .promise()
  .then(data => console.log(data.Items))
  .catch(console.error)

## Get Item
dynamoDB
  .get({
    TableName: "my-table",
    Key: {
      id: "123", // id is the Partition Key, '123' is the value of it
    },
  })
  .promise()
  .then(data => console.log(data.Item))
  .catch(console.error)

## Put Item aka Write/Create
dynamoDB
  .put({
    Item: {
      id: "12346",
      name: "John Doe",
      email: "john@doe.io",
    },
    TableName: "my-table",
  })
  .promise()
  .then(data => console.log(data.Attributes))
  .catch(console.error)

## Query for a Set of Items
dynamoDB
  .query({
    TableName: 'my-table',
    KeyConditionExpression: 'id = :hashKey and date > :rangeKey'
    ExpressionAttributeValues: {
      ':hashKey': '123',
      ':rangeKey': 20150101
    }
  })
  .promise()
  .then(data => console.log(data.Items))
  .catch(console.error);

## Query (and Scan) DynamoDB Pagination
const getAll = async () => {
  let result, accumulated, ExclusiveStartKey;
  do {
    result = await DynamoDB.query({
      TableName: argv.table,
      ExclusiveStartKey,
      Limit: 100,
      KeyConditionExpression: 'id = :hashKey and date > :rangeKey'
      ExpressionAttributeValues: {
        ':hashKey': '123',
        ':rangeKey': 20150101
      },
    }).promise();

    ExclusiveStartKey = result.LastEvaluatedKey;
    accumulated = [...accumulated, ...result.Items];
  } while (result.Items.length || result.LastEvaluatedKey);

  return accumulated;
};
getAll()
  .then(console.log)
  .catch(console.error);