NodeJS DynamoDB Cheat Sheet (straight to the point!)

nodejs-dynamodb-cheat-sheet.js

// Simplified from https://github.com/dabit3/dynamodb-documentclient-cheat-sheet

/**
 * DynamoDB.DocumentClient
 */
const dynamoDbClient = new AWS.DynamoDB.DocumentClient({
  region: 'ap-southeast-1',
  convertEmptyValues: true,
  httpOptions: {
    connectTimeout: 1000, // 1s
    timeout: 100, // 100ms
  },
})

/**
 * Query
 */
const params = {
  TableName: 'table-name',
  IndexName: 'optional-gsi-name',
  Limit: 10,
  ScanIndexForward: false, // order sk in desc order
  KeyConditionExpression: 'pk = :pk and begins_with(gsi2sk, :gsi2sk)',
  ExpressionAttributeValues: { ':pk': 'pk-value', ':gsi2sk': 'sk-value' },
}

const data = await dynamoDbClient.query(params).promise()
const items = data.Items

/**
 * Get
 */
const params = {
  TableName: 'table-name',
  Key: {
    pk: 'pk-value',
    sk: 'sk-value',
  },
}

const data = await dynamoDbClient.get(params).promise()
const item = data.Item

/**
 * Update
 */
const params = {
  TableName: 'table-name',
  Key: { pk: 'pk-value', sk: 'sk-value' },
  UpdateExpression: 'set someAttrName = :someAttrName',
  ExpressionAttributeValues: { ':someAttrName': 'new-attr-value' },
}

await dynamoDbClient.update(item).promise()

/**
 * Update (if attr name is a DynamoDB reserved keyword)
 *
 * Set an alias "#someAttrName" to the actual key name ":someAttrName".
 * DynamoDB will automatically translate it accordingly.
 */
const params = {
  TableName: 'table-name',
  Key: { pk: 'pk-value', sk: 'sk-value' },
  UpdateExpression: 'set #someAttrName = :someAttrName',
  KeyConditionExpression: { '#someAttrName': ':someAttrName' },
  ExpressionAttributeNames: { '#someAttrName': 'someAttrName' },
  ExpressionAttributeValues: { ':someAttrName': 'new-attr-value' },
}

await dynamoDbClient.update(item).promise()

/**
 * BatchGet
 */
const params = {
  RequestItems: {
    'table-name': {
      Keys: [
        { pk: 'pk-value', sk: 'sk-value-1' },
        { pk: 'pk-value', sk: 'sk-value-2' },
      ],
    },
  },
}

const data = await dynamoDbClient.batchGet(params).promise()
const items = data.Responses['table-name']