Exemplos de código do DynamoDB usando AWS SDKs
Os exemplos de código a seguir mostram como usar o DynamoDB com um Kit de Desenvolvimento de Software (SDK) da AWS.
As noções básicas são exemplos de código que mostram como realizar as operações essenciais em um serviço.
Ações são trechos de código de programas maiores e devem ser executadas em contexto. Embora as ações mostrem como chamar funções de serviço individuais, você pode ver as ações no contexto em seus cenários relacionados.
Os cenários são exemplos de código que mostram como realizar tarefas específicas chamando várias funções dentro de um serviço ou combinadas com outros Serviços da AWS.
Para ver uma lista completa dos Guias do desenvolvedor de SDK da AWS e exemplos de código, consulte Usar o DynamoDB com um AWS SDK. Este tópico também inclui informações sobre como começar e detalhes sobre versões anteriores do SDK.
Conceitos básicos
O exemplo de código a seguir mostra como começar a usar o DynamoDB.
- .NET
-
- AWS SDK for .NET
-
using Amazon.DynamoDBv2;
using Amazon.DynamoDBv2.Model;
namespace DynamoDB_Actions;
public static class HelloDynamoDB
{
static async Task Main(string[] args)
{
var dynamoDbClient = new AmazonDynamoDBClient();
Console.WriteLine($"Hello Amazon Dynamo DB! Following are some of your tables:");
Console.WriteLine();
// You can use await and any of the async methods to get a response.
// Let's get the first five tables.
var response = await dynamoDbClient.ListTablesAsync(
new ListTablesRequest()
{
Limit = 5
});
foreach (var table in response.TableNames)
{
Console.WriteLine($"\tTable: {table}");
Console.WriteLine();
}
}
}
- C++
-
- SDK para C++
-
Código para o arquivo CMakeLists.txt do CMake.
# Set the minimum required version of CMake for this project.
cmake_minimum_required(VERSION 3.13)
# Set the AWS service components used by this project.
set(SERVICE_COMPONENTS dynamodb)
# Set this project's name.
project("hello_dynamodb")
# Set the C++ standard to use to build this target.
# At least C++ 11 is required for the AWS SDK for C++.
set(CMAKE_CXX_STANDARD 11)
# Use the MSVC variable to determine if this is a Windows build.
set(WINDOWS_BUILD ${MSVC})
if (WINDOWS_BUILD) # Set the location where CMake can find the installed libraries for the AWS SDK.
string(REPLACE ";" "/aws-cpp-sdk-all;" SYSTEM_MODULE_PATH "${CMAKE_SYSTEM_PREFIX_PATH}/aws-cpp-sdk-all")
list(APPEND CMAKE_PREFIX_PATH ${SYSTEM_MODULE_PATH})
endif ()
# Find the AWS SDK for C++ package.
find_package(AWSSDK REQUIRED COMPONENTS ${SERVICE_COMPONENTS})
if (WINDOWS_BUILD AND AWSSDK_INSTALL_AS_SHARED_LIBS)
# Copy relevant AWS SDK for C++ libraries into the current binary directory for running and debugging.
# set(BIN_SUB_DIR "/Debug") # if you are building from the command line you may need to uncomment this
# and set the proper subdirectory to the executables' location.
AWSSDK_CPY_DYN_LIBS(SERVICE_COMPONENTS "" ${CMAKE_CURRENT_BINARY_DIR}${BIN_SUB_DIR})
endif ()
add_executable(${PROJECT_NAME}
hello_dynamodb.cpp)
target_link_libraries(${PROJECT_NAME}
${AWSSDK_LINK_LIBRARIES})
Código para o arquivo de origem hello_dynamodb.cpp.
#include <aws/core/Aws.h>
#include <aws/dynamodb/DynamoDBClient.h>
#include <aws/dynamodb/model/ListTablesRequest.h>
#include <iostream>
/*
* A "Hello DynamoDB" starter application which initializes an Amazon DynamoDB (DynamoDB) client and lists the
* DynamoDB tables.
*
* main function
*
* Usage: 'hello_dynamodb'
*
*/
int main(int argc, char **argv) {
Aws::SDKOptions options;
// Optionally change the log level for debugging.
// options.loggingOptions.logLevel = Utils::Logging::LogLevel::Debug;
Aws::InitAPI(options); // Should only be called once.
int result = 0;
{
Aws::Client::ClientConfiguration clientConfig;
// Optional: Set to the AWS Region (overrides config file).
// clientConfig.region = "us-east-1";
Aws::DynamoDB::DynamoDBClient dynamodbClient(clientConfig);
Aws::DynamoDB::Model::ListTablesRequest listTablesRequest;
listTablesRequest.SetLimit(50);
do {
const Aws::DynamoDB::Model::ListTablesOutcome &outcome = dynamodbClient.ListTables(
listTablesRequest);
if (!outcome.IsSuccess()) {
std::cout << "Error: " << outcome.GetError().GetMessage() << std::endl;
result = 1;
break;
}
for (const auto &tableName: outcome.GetResult().GetTableNames()) {
std::cout << tableName << std::endl;
}
listTablesRequest.SetExclusiveStartTableName(
outcome.GetResult().GetLastEvaluatedTableName());
} while (!listTablesRequest.GetExclusiveStartTableName().empty());
}
Aws::ShutdownAPI(options); // Should only be called once.
return result;
}
- Java
-
- SDK para Java 2.x
-
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.dynamodb.DynamoDbClient;
import software.amazon.awssdk.services.dynamodb.model.DynamoDbException;
import software.amazon.awssdk.services.dynamodb.model.ListTablesRequest;
import software.amazon.awssdk.services.dynamodb.model.ListTablesResponse;
import java.util.List;
/**
* Before running this Java V2 code example, set up your development
* environment, including your credentials.
*
* For more information, see the following documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*/
public class ListTables {
public static void main(String[] args) {
System.out.println("Listing your Amazon DynamoDB tables:\n");
Region region = Region.US_EAST_1;
DynamoDbClient ddb = DynamoDbClient.builder()
.region(region)
.build();
listAllTables(ddb);
ddb.close();
}
public static void listAllTables(DynamoDbClient ddb) {
boolean moreTables = true;
String lastName = null;
while (moreTables) {
try {
ListTablesResponse response = null;
if (lastName == null) {
ListTablesRequest request = ListTablesRequest.builder().build();
response = ddb.listTables(request);
} else {
ListTablesRequest request = ListTablesRequest.builder()
.exclusiveStartTableName(lastName).build();
response = ddb.listTables(request);
}
List<String> tableNames = response.tableNames();
if (tableNames.size() > 0) {
for (String curName : tableNames) {
System.out.format("* %s\n", curName);
}
} else {
System.out.println("No tables found!");
System.exit(0);
}
lastName = response.lastEvaluatedTableName();
if (lastName == null) {
moreTables = false;
}
} catch (DynamoDbException e) {
System.err.println(e.getMessage());
System.exit(1);
}
}
System.out.println("\nDone!");
}
}
- JavaScript
-
- SDK para JavaScript (v3)
-
Para ter mais detalhes sobre como trabalhar com o DynamoDB no AWS SDK for JavaScript, consulte Programming DynamoDB with JavaScript.
import { ListTablesCommand, DynamoDBClient } from "@aws-sdk/client-dynamodb";
const client = new DynamoDBClient({});
export const main = async () => {
const command = new ListTablesCommand({});
const response = await client.send(command);
console.log(response.TableNames.join("\n"));
return response;
};
- Python
-
- SDK para Python (Boto3).
-
import boto3
# Create a DynamoDB client using the default credentials and region
dynamodb = boto3.client("dynamodb")
# Initialize a paginator for the list_tables operation
paginator = dynamodb.get_paginator("list_tables")
# Create a PageIterator from the paginator
page_iterator = paginator.paginate(Limit=10)
# List the tables in the current AWS account
print("Here are the DynamoDB tables in your account:")
# Use pagination to list all tables
table_names = []
for page in page_iterator:
for table_name in page.get("TableNames", []):
print(f"- {table_name}")
table_names.append(table_name)
if not table_names:
print("You don't have any DynamoDB tables in your account.")
else:
print(f"\nFound {len(table_names)} tables.")
- Ruby
-
- SDK para Ruby
-
require 'aws-sdk-dynamodb'
require 'logger'
# DynamoDBManager is a class responsible for managing DynamoDB operations
# such as listing all tables in the current AWS account.
class DynamoDBManager
def initialize(client)
@client = client
@logger = Logger.new($stdout)
end
# Lists and prints all DynamoDB tables in the current AWS account.
def list_tables
@logger.info('Here are the DynamoDB tables in your account:')
paginator = @client.list_tables(limit: 10)
table_names = []
paginator.each_page do |page|
page.table_names.each do |table_name|
@logger.info("- #{table_name}")
table_names << table_name
end
end
if table_names.empty?
@logger.info("You don't have any DynamoDB tables in your account.")
else
@logger.info("\nFound #{table_names.length} tables.")
end
end
end
if $PROGRAM_NAME == __FILE__
dynamodb_client = Aws::DynamoDB::Client.new
manager = DynamoDBManager.new(dynamodb_client)
manager.list_tables
end