Aggiornamento di un elemento DynamoDB con un TTL con un SDK AWS - Amazon DynamoDB

Aggiornamento di un elemento DynamoDB con un TTL con un SDK AWS

Gli esempi di codice seguenti mostrano come aggiornare il valore TTL di un elemento.

Java
SDK per Java 2.x

Per aggiornare il TTL su un elemento DynamoDB esistente in una tabella.

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 java.util.HashMap; import java.util.Map; import java.util.Optional; public UpdateItemResponse updateItemWithTTL( final String tableName, final String primaryKeyValue, final String sortKeyValue) { // 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 + (DAYS_TO_EXPIRE * SECONDS_PER_DAY); // Create the key map for the item to update final Map<String, AttributeValue> keyMap = new HashMap<>(); keyMap.put(PRIMARY_KEY_ATTR, AttributeValue.builder().s(primaryKeyValue).build()); keyMap.put(SORT_KEY_ATTR, AttributeValue.builder().s(sortKeyValue).build()); // Create the expression attribute values final Map<String, AttributeValue> expressionAttributeValues = new HashMap<>(); expressionAttributeValues.put( ":c", AttributeValue.builder().n(String.valueOf(currentTime)).build()); expressionAttributeValues.put( ":e", AttributeValue.builder().n(String.valueOf(expireDate)).build()); final UpdateItemRequest request = UpdateItemRequest.builder() .tableName(tableName) .key(keyMap) .updateExpression(UPDATE_EXPRESSION) .expressionAttributeValues(expressionAttributeValues) .build(); try { final UpdateItemResponse response = dynamoDbClient.updateItem(request); System.out.println(String.format(SUCCESS_MESSAGE, tableName)); return response; } catch (ResourceNotFoundException e) { System.err.format(TABLE_NOT_FOUND_ERROR, tableName); throw e; } catch (DynamoDbException e) { System.err.println(e.getMessage()); throw e; } }
  • Per informazioni dettagliate sulle API, consulta UpdateItem nella Documentazione di riferimento API AWS SDK for Java 2.x.

JavaScript
SDK per JavaScript (v3)
import { DynamoDBClient, UpdateItemCommand } from "@aws-sdk/client-dynamodb"; import { marshall, unmarshall } from "@aws-sdk/util-dynamodb"; export const updateItem = async (tableName, partitionKey, sortKey, region = 'us-east-1') => { 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; } } // Example usage (commented out for testing) // updateItem('your-table-name', 'your-partition-key-value', 'your-sort-key-value');
  • Per informazioni dettagliate sulle API, consulta UpdateItem nella Documentazione di riferimento API AWS SDK per JavaScript.

Python
SDK per Python (Boto3)
from datetime import datetime, timedelta import boto3 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" )
  • Per informazioni dettagliate sull'API, consulta UpdateItem nella Documentazione di riferimento delle API SDK AWS per Python (Boto3).

Per un elenco completo delle guide per gli sviluppatori di SDK AWS ed esempi di codice, consulta la sezione Utilizzo di DynamoDB con un SDK AWS. Questo argomento include anche informazioni su come iniziare e dettagli sulle versioni precedenti dell'SDK.