Aktualisieren Sie ein DynamoDB-Element mit einer TTL mithilfe eines SDK AWS

Die folgenden Codebeispiele zeigen, wie die TTL eines Elements aktualisiert wird.

Java

SDK für Java 2.x

Aktualisieren Sie TTL für ein vorhandenes DynamoDB-Element in einer Tabelle.

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);

• Einzelheiten zur API finden Sie unter UpdateItemAPI-Referenz.AWS SDK for Java 2.x

JavaScript

SDK für JavaScript (v3)

// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
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');

• Einzelheiten zur API finden Sie UpdateItemin der AWS SDK for JavaScript API-Referenz.

Python

SDK für Python (Boto3)

# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
# SPDX-License-Identifier: Apache-2.0
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')

• Einzelheiten zur API finden Sie UpdateItemin AWS SDK for Python (Boto3) API Reference.

Eine vollständige Liste der AWS SDK-Entwicklerhandbücher und Codebeispiele finden Sie unter. DynamoDB mit einem SDK verwenden AWS Dieses Thema enthält auch Informationen zu den ersten Schritten und Details zu früheren SDK-Versionen.