DynamoDB: Get Last Inserted Item (Guide w/ Code Examples)

DynamoDB has no table-wide insertion order. For items in one partition, store a sortable creation timestamp as sk and query in descending order. This retrieves the latest timestamp values, not the most recently modified items.

Install @aws-sdk/client-dynamodb and @aws-sdk/lib-dynamodb, use an ES module on a supported Node.js runtime, and configure an AWS Region and credentials. The examples use an existing Orders table with String keys pk and sk unless an index or timestamp key is described.

import { DynamoDBClient } from "@aws-sdk/client-dynamodb";
import { DynamoDBDocumentClient, QueryCommand } from "@aws-sdk/lib-dynamodb";

const ddb = DynamoDBDocumentClient.from(new DynamoDBClient({}));

const items = [];
let lastKey;
do {
  const page = await ddb.send(new QueryCommand({
    TableName: "Orders",
    KeyConditionExpression: "#pk = :pk",
    ExpressionAttributeNames: { "#pk": "pk" },
    ExpressionAttributeValues: { ":pk": "CUSTOMER#123" },
    ScanIndexForward: false,
    Limit: 1 - items.length,
    ExclusiveStartKey: lastKey,
  }));
  items.push(...(page.Items ?? []));
  lastKey = page.LastEvaluatedKey;
} while (items.length < 1 && lastKey && Object.keys(lastKey).length > 0);
console.log(items);

Use uniform UTC timestamps, with a tie-breaker when two items may share a timestamp. For latest items across customers, design an appropriate index; avoid a single hot global key at high write rates.

Reference: AWS Query API. For related access patterns, see DynamoDB query examples.