Actualización de un elemento de DynamoDB con un TTL mediante un AWS SDK

En los siguientes ejemplos de código, se muestra cómo actualizar el TTL de un elemento.

Java

SDK para Java 2.x

Actualice el TTL en un elemento de DynamoDB existente en una tabla.

import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.dynamodb.DynamoDbClient;
import software.amazon.awssdk.services.dynamodb.model.AttributeValue;
import software.amazon.awssdk.services.dynamodb.model.DynamoDbException;
import software.amazon.awssdk.services.dynamodb.model.ResourceNotFoundException;
import software.amazon.awssdk.services.dynamodb.model.UpdateItemRequest;
import software.amazon.awssdk.services.dynamodb.model.UpdateItemResponse;
import software.amazon.awssdk.utils.ImmutableMap;

import java.util.Map;
import java.util.Optional;

        // Get current time in epoch second format
        final long currentTime = System.currentTimeMillis() / 1000;
        // Calculate expiration time 90 days from now in epoch second format
        final long expireDate = currentTime + (90 * 24 * 60 * 60);
        // An expression that defines one or more attributes to be updated, the action to be performed on them, and new values for them.
        final String updateExpression = "SET updatedAt=:c, expireAt=:e";

        final ImmutableMap<String, AttributeValue> keyMap =
                ImmutableMap.of("primaryKey", AttributeValue.fromS(primaryKey),
                        "sortKey", AttributeValue.fromS(sortKey));
        final Map<String, AttributeValue> expressionAttributeValues = ImmutableMap.of(
                ":c", AttributeValue.builder().s(String.valueOf(currentTime)).build(),
                ":e", AttributeValue.builder().s(String.valueOf(expireDate)).build()
        );

        final UpdateItemRequest request = UpdateItemRequest.builder()
                .tableName(tableName)
                .key(keyMap)
                .updateExpression(updateExpression)
                .expressionAttributeValues(expressionAttributeValues)
                .build();
        try (DynamoDbClient ddb = DynamoDbClient.builder()
                .region(region)
                .build()) {
            final UpdateItemResponse response = ddb.updateItem(request);
            System.out.println(tableName + " UpdateItem operation with TTL successful. Request id is "
                    + response.responseMetadata().requestId());
        } catch (ResourceNotFoundException e) {
            System.err.format("Error: The Amazon DynamoDB table \"%s\" can't be found.\n", tableName);
            System.exit(1);
        } catch (DynamoDbException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }
        System.exit(0);

• Para obtener información sobre la API, consulte UpdateItem en la referencia de la API de AWS SDK for Java 2.x.

JavaScript

SDK para JavaScript (v3)

import { DynamoDBClient, UpdateItemCommand } from "@aws-sdk/client-dynamodb";
import { marshall, unmarshall } from "@aws-sdk/util-dynamodb";

async function updateDynamoDBItem(tableName, region, partitionKey, sortKey) {
    const client = new DynamoDBClient({
        region: region,
        endpoint: `https://dynamodb.${region}.amazonaws.com`
    });

    const currentTime = Math.floor(Date.now() / 1000);
    const expireAt = Math.floor((Date.now() + 90 * 24 * 60 * 60 * 1000) / 1000);

    const params = {
        TableName: tableName,
        Key: marshall({
            partitionKey: partitionKey,
            sortKey: sortKey
        }),
        UpdateExpression: "SET updatedAt = :c, expireAt = :e",
        ExpressionAttributeValues: marshall({
            ":c": currentTime,
            ":e": expireAt
        }),
    };

    try {
        const data = await client.send(new UpdateItemCommand(params));
        const responseData = unmarshall(data.Attributes);
        console.log("Item updated successfully: %s", responseData);
        return responseData;
    } catch (err) {
        console.error("Error updating item:", err);
        throw err;
    }
}

//enter your values here
updateDynamoDBItem('your-table-name', 'us-east-1', 'your-partition-key-value', 'your-sort-key-value');

• Para obtener información sobre la API, consulte UpdateItem en la referencia de la API de AWS SDK for JavaScript.

Python

SDK para Python (Boto3)

import boto3
from datetime import datetime, timedelta

def update_dynamodb_item(table_name, region, primary_key, sort_key):
    """
    Update an existing DynamoDB item with a TTL.
    :param table_name: Name of the DynamoDB table
    :param region: AWS Region of the table - example `us-east-1`
    :param primary_key: one attribute known as the partition key.
    :param sort_key: Also known as a range attribute.
    :return: Void (nothing)
    """
    try:
        # Create the DynamoDB resource.
        dynamodb = boto3.resource('dynamodb', region_name=region)
        table = dynamodb.Table(table_name)

        # Get the current time in epoch second format
        current_time = int(datetime.now().timestamp())

        # Calculate the expireAt time (90 days from now) in epoch second format
        expire_at = int((datetime.now() + timedelta(days=90)).timestamp())

        table.update_item(
            Key={
                'partitionKey': primary_key,
                'sortKey': sort_key
            },
            UpdateExpression="set updatedAt=:c, expireAt=:e",
            ExpressionAttributeValues={
                ':c': current_time,
                ':e': expire_at
            },
        )

        print("Item updated successfully.")
    except Exception as e:
        print(f"Error updating item: {e}")


# Replace with your own values
update_dynamodb_item('your-table-name', 'us-west-2', 'your-partition-key-value', 'your-sort-key-value')

• Para obtener información la API, consulte UpdateItem en la referencia de la API de AWS SDK para Python (Boto3).

Para obtener una lista completa de las guías para desarrolladores del AWS SDK y ejemplos de código, consulte Uso de DynamoDB con un SDK de AWS. En este tema también se incluye información sobre cómo comenzar a utilizar el SDK y detalles sobre sus versiones anteriores.