通过 DynamoDB 触发器调用 Lambda 函数 - Amazon DynamoDB
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通过 DynamoDB 触发器调用 Lambda 函数

以下代码示例演示了如何实现一个 Lambda 函数,该函数接收通过接收来自 DynamoDB 流的记录而触发的事件。该函数检索 DynamoDB 有效负载,并记录下记录内容。

.NET
Amazon SDK for .NET
注意

在 GitHub 上查看更多内容。在无服务器示例存储库中查找完整示例,并了解如何进行设置和运行。

通过 .NET 将 DynamoDB 事件与 Lambda 结合使用。

// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved. // SPDX-License-Identifier: Apache-2.0 using System.Text.Json; using System.Text; using Amazon.Lambda.Core; using Amazon.Lambda.DynamoDBEvents; // Assembly attribute to enable the Lambda function's JSON input to be converted into a .NET class. [assembly: LambdaSerializer(typeof(Amazon.Lambda.Serialization.SystemTextJson.DefaultLambdaJsonSerializer))] namespace AWSLambda_DDB; public class Function { public void FunctionHandler(DynamoDBEvent dynamoEvent, ILambdaContext context) { context.Logger.LogInformation($"Beginning to process {dynamoEvent.Records.Count} records..."); foreach (var record in dynamoEvent.Records) { context.Logger.LogInformation($"Event ID: {record.EventID}"); context.Logger.LogInformation($"Event Name: {record.EventName}"); context.Logger.LogInformation(JsonSerializer.Serialize(record)); } context.Logger.LogInformation("Stream processing complete."); } }
Go
适用于 Go V2 的 SDK
注意

在 GitHub 上查看更多内容。在无服务器示例存储库中查找完整示例,并了解如何进行设置和运行。

使用 Go 将 DynamoDB 事件与 Lambda 结合使用。

// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved. // SPDX-License-Identifier: Apache-2.0 package main import ( "context" "github.com/aws/aws-lambda-go/lambda" "github.com/aws/aws-lambda-go/events" "fmt" ) func HandleRequest(ctx context.Context, event events.DynamoDBEvent) (*string, error) { if len(event.Records) == 0 { return nil, fmt.Errorf("received empty event") } for _, record := range event.Records { LogDynamoDBRecord(record) } message := fmt.Sprintf("Records processed: %d", len(event.Records)) return &message, nil } func main() { lambda.Start(HandleRequest) } func LogDynamoDBRecord(record events.DynamoDBEventRecord){ fmt.Println(record.EventID) fmt.Println(record.EventName) fmt.Printf("%+v\n", record.Change) }
JavaScript
适用于 JavaScript 的 SDK (v3)
注意

在 GitHub 上查看更多内容。在无服务器示例存储库中查找完整示例,并了解如何进行设置和运行。

使用 JavaScript 将 DynamoDB 事件与 Lambda 结合使用。

// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved. // SPDX-License-Identifier: Apache-2.0 exports.handler = async (event, context) => { console.log(JSON.stringify(event, null, 2)); event.Records.forEach(record => { logDynamoDBRecord(record); }); }; const logDynamoDBRecord = (record) => { console.log(record.eventID); console.log(record.eventName); console.log(`DynamoDB Record: ${JSON.stringify(record.dynamodb)}`); };

使用 TypeScript 将 DynamoDB 事件与 Lambda 结合使用。

// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved. // SPDX-License-Identifier: Apache-2.0 export const handler = async (event, context) => { console.log(JSON.stringify(event, null, 2)); event.Records.forEach(record => { logDynamoDBRecord(record); }); } const logDynamoDBRecord = (record) => { console.log(record.eventID); console.log(record.eventName); console.log(`DynamoDB Record: ${JSON.stringify(record.dynamodb)}`); };
PHP
适用于 PHP 的 SDK
注意

在 GitHub 上查看更多内容。在无服务器示例存储库中查找完整示例,并了解如何进行设置和运行。

使用 PHP 将 DynamoDB 事件与 Lambda 结合使用。

// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved. // SPDX-License-Identifier: Apache-2.0 <?php # using bref/bref and bref/logger for simplicity use Bref\Context\Context; use Bref\Event\DynamoDb\DynamoDbEvent; use Bref\Event\DynamoDb\DynamoDbHandler; use Bref\Logger\StderrLogger; require __DIR__ . '/vendor/autoload.php'; class Handler extends DynamoDbHandler { private StderrLogger $logger; public function __construct(StderrLogger $logger) { $this->logger = $logger; } /** * @throws JsonException * @throws \Bref\Event\InvalidLambdaEvent */ public function handleDynamoDb(DynamoDbEvent $event, Context $context): void { $this->logger->info("Processing DynamoDb table items"); $records = $event->getRecords(); foreach ($records as $record) { $eventName = $record->getEventName(); $keys = $record->getKeys(); $old = $record->getOldImage(); $new = $record->getNewImage(); $this->logger->info("Event Name:".$eventName."\n"); $this->logger->info("Keys:". json_encode($keys)."\n"); $this->logger->info("Old Image:". json_encode($old)."\n"); $this->logger->info("New Image:". json_encode($new)); // TODO: Do interesting work based on the new data // Any exception thrown will be logged and the invocation will be marked as failed } $totalRecords = count($records); $this->logger->info("Successfully processed $totalRecords items"); } } $logger = new StderrLogger(); return new Handler($logger);
Python
SDK for Python(Boto3)
注意

在 GitHub 上查看更多内容。在无服务器示例存储库中查找完整示例,并了解如何进行设置和运行。

通过 Python 将 DynamoDB 事件与 Lambda 结合使用。

# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved. # SPDX-License-Identifier: Apache-2.0 import json def lambda_handler(event, context): print(json.dumps(event, indent=2)) for record in event['Records']: log_dynamodb_record(record) def log_dynamodb_record(record): print(record['eventID']) print(record['eventName']) print(f"DynamoDB Record: {json.dumps(record['dynamodb'])}")
Ruby
适用于 Ruby 的 SDK
注意

在 GitHub 上查看更多内容。在无服务器示例存储库中查找完整示例,并了解如何进行设置和运行。

通过 Ruby 将 DynamoDB 事件与 Lambda 结合使用。

# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved. # SPDX-License-Identifier: Apache-2.0 def lambda_handler(event:, context:) return 'received empty event' if event['Records'].empty? event['Records'].each do |record| log_dynamodb_record(record) end "Records processed: #{event['Records'].length}" end def log_dynamodb_record(record) puts record['eventID'] puts record['eventName'] puts "DynamoDB Record: #{JSON.generate(record['dynamodb'])}" end
Rust
适用于 Rust 的 SDK
注意

在 GitHub 上查看更多内容。在无服务器示例存储库中查找完整示例,并了解如何进行设置和运行。

使用 Rust 将 DynamoDB 事件与 Lambda 结合使用。

// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved. // SPDX-License-Identifier: Apache-2.0 use lambda_runtime::{service_fn, tracing, Error, LambdaEvent}; use aws_lambda_events::{ event::dynamodb::{Event, EventRecord}, }; // Built with the following dependencies: //lambda_runtime = "0.11.1" //serde_json = "1.0" //tokio = { version = "1", features = ["macros"] } //tracing = { version = "0.1", features = ["log"] } //tracing-subscriber = { version = "0.3", default-features = false, features = ["fmt"] } //aws_lambda_events = "0.15.0" async fn function_handler(event: LambdaEvent<Event>) ->Result<(), Error> { let records = &event.payload.records; tracing::info!("event payload: {:?}",records); if records.is_empty() { tracing::info!("No records found. Exiting."); return Ok(()); } for record in records{ log_dynamo_dbrecord(record); } tracing::info!("Dynamo db records processed"); // Prepare the response Ok(()) } fn log_dynamo_dbrecord(record: &EventRecord)-> Result<(), Error>{ tracing::info!("EventId: {}", record.event_id); tracing::info!("EventName: {}", record.event_name); tracing::info!("DynamoDB Record: {:?}", record.change ); Ok(()) } #[tokio::main] async fn main() -> Result<(), Error> { tracing_subscriber::fmt() .with_max_level(tracing::Level::INFO) .with_target(false) .without_time() .init(); let func = service_fn(function_handler); lambda_runtime::run(func).await?; Ok(()) }

有关 Amazon SDK 开发人员指南和代码示例的完整列表,请参阅 结合使用 DynamoDB 与 Amazon SDK。本主题还包括有关入门的信息以及有关先前的 SDK 版本的详细信息。