Fetch last item of the aws dynamodb table

Question

So I wanted to fetch the last item/row of my dynamodb table but i am not finding resources. My primary key is id having series of incremented numbers such as 1,2,3... for each row respectively.

This is my function.

async function readMessage(){
   const params = {
        TableName: table,
    };
    return dynamo.getItem(params).promise();
}

I am not sure as to what i should be adding in my params.

Answer 1

DynamoDB has two types of primary keys:

• Partition key – A simple primary key, composed of one attribute known as the partition key.

• Partition key and sort key – Referred to as a composite primary key, this type of key is composed of two attributes. The first attribute is the partition key, and the second attribute is the sort key.

When fetching an item by partition key, you need to specify the exact partition key. You cannot fetch the max/min partition key.

Instead, you may want to create a sort key with a timestamp (or the ID if it's a sequential number) and use the sort key to fetch the last item.

Check out the AWS docs on Choosing the Right Partition Key for more info.