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TTL 使用 使用 更新 DynamoDB 項目 AWS SDK
下列程式碼範例示範如何更新項目的 TTL。
- Java
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- SDK 適用於 Java 2.x
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資料表中現有 DynamoDB 項目TTL的更新。
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);
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如需API詳細資訊,請參閱 參考 UpdateItem中的 。 AWS SDK for Java 2.x API
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- JavaScript
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- SDK 適用於 JavaScript (v3)
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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');
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如需API詳細資訊,請參閱 參考 UpdateItem中的 。 AWS SDK for JavaScript API
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- Python
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- SDK for Python (Boto3)
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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')
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如需API詳細資訊,請參閱 UpdateItem 中的 AWS SDK for Python (Boto3) API參考 。
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如需開發人員指南和程式碼範例的完整清單 AWS SDK,請參閱 搭配 使用 DynamoDB AWS SDK。本主題也包含有關入門的資訊,以及先前SDK版本的詳細資訊。
儲存EXIF和其他影像資訊
使用API閘道來叫用 Lambda 函數