Pagination with SDK in DynamoDB - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to fetch the first page of items from a DynamoDB table using the SDK.

DynamoDB

const params = { TableName: 'Users', Limit: [1] };
const data = await dynamoDbClient.scan(params).promise();

Drag options to blanks, or click blank then click option'

Anull

B100

C0

D10

Attempts:

3 left

💡 Hint

Common Mistakes

Setting Limit to 0 returns no items.

Using null for Limit causes an error.

The Limit parameter controls how many items are returned per page. Setting it to 10 fetches the first 10 items.

2fill in blank

medium

Complete the code to continue fetching the next page using the LastEvaluatedKey.

DynamoDB

const params = { TableName: 'Users', Limit: 10, ExclusiveStartKey: [1] };
const data = await dynamoDbClient.scan(params).promise();

Drag options to blanks, or click blank then click option'

Anull

Bdata.LastEvaluatedKey

Cundefined

D{}

Attempts:

3 left

💡 Hint

Common Mistakes

Passing null or undefined causes DynamoDB to start from the beginning.

Using an empty object {} does not work as a start key.

The ExclusiveStartKey tells DynamoDB where to start the next page. Use data.LastEvaluatedKey from the previous response.

3fill in blank

hard

Fix the error in the code to correctly check if there are more pages to fetch.

DynamoDB

if (data.[1]) {
  // fetch next page
}

Drag options to blanks, or click blank then click option'

AMoreResults

BNextPageKey

CLastEvaluatedKey

DHasNext

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect property names like NextPageKey or HasNext.

Checking for a boolean instead of the key object.

The DynamoDB SDK uses LastEvaluatedKey to indicate if more pages exist.

4fill in blank

hard

Fill both blanks to correctly set up the scan parameters for paginated fetching.

DynamoDB

const params = { TableName: 'Orders', Limit: [1], ExclusiveStartKey: [2] };
const data = await dynamoDbClient.scan(params).promise();

Drag options to blanks, or click blank then click option'

A20

Bdata.LastEvaluatedKey

Cnull

D10

Attempts:

3 left

💡 Hint

Common Mistakes

Using data.LastEvaluatedKey on the first page causes errors.

Setting Limit too high or zero.

Set Limit to 20 to fetch 20 items per page. Use null for ExclusiveStartKey on the first page.

5fill in blank

hard

Fill all three blanks to build a loop that fetches all pages from a DynamoDB table.

DynamoDB

let lastKey = [1];
do {
  const params = { TableName: 'Products', Limit: [2], ExclusiveStartKey: lastKey };
  const data = await dynamoDbClient.scan(params).promise();
  // process data.Items
  lastKey = data.[3];
} while (lastKey);

Drag options to blanks, or click blank then click option'

Anull

B50

CLastEvaluatedKey

Dundefined

Attempts:

3 left

💡 Hint

Common Mistakes

Starting lastKey as undefined causes errors.

Not updating lastKey inside the loop.

Using wrong property name for the next key.

Initialize lastKey as null to start from the beginning. Set Limit to 50 items per page. Update lastKey with data.LastEvaluatedKey to continue paging.