Há mais AWS SDK exemplos disponíveis no GitHub repositório AWS Doc SDK Examples
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Exemplos do DynamoDB usando para C++ SDK
Os exemplos de código a seguir mostram como realizar ações e implementar cenários comuns usando o AWS SDK for C++ com o DynamoDB.
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, é possível 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.
Cada exemplo inclui um link para o código-fonte completo, onde você pode encontrar instruções sobre como configurar e executar o código no contexto.
Conceitos básicos
O exemplo de código a seguir mostra como começar a usar o DynamoDB.
- SDKpara C++
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nota
Tem mais sobre GitHub. Encontre o exemplo completo e saiba como configurar e executar no Repositório de exemplos de código da AWS
. Código para o CMakeLists arquivo.txtCMake.
# 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; }
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Para API obter detalhes, consulte ListTablesem AWS SDK for C++ APIReferência.
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Conceitos básicos
O exemplo de código a seguir mostra como:
Criar uma tabela que possa conter dados de filmes.
Colocar, obter e atualizar um único filme na tabela.
Grave dados do filme na tabela a partir de um JSON arquivo de amostra.
Consultar filmes que foram lançados em determinado ano.
Verificar filmes que foram lançados em um intervalo de anos.
Excluir um filme da tabela e, depois, excluir a tabela.
- SDKpara C++
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nota
Tem mais sobre GitHub. Encontre o exemplo completo e saiba como configurar e executar no Repositório de exemplos de código da AWS
. { Aws::Client::ClientConfiguration clientConfig; // 1. Create a table with partition: year (N) and sort: title (S). (CreateTable) if (AwsDoc::DynamoDB::createMoviesDynamoDBTable(clientConfig)) { AwsDoc::DynamoDB::dynamodbGettingStartedScenario(clientConfig); // 9. Delete the table. (DeleteTable) AwsDoc::DynamoDB::deleteMoviesDynamoDBTable(clientConfig); } } //! Scenario to modify and query a DynamoDB table. /*! \sa dynamodbGettingStartedScenario() \param clientConfiguration: AWS client configuration. \return bool: Function succeeded. */ bool AwsDoc::DynamoDB::dynamodbGettingStartedScenario( const Aws::Client::ClientConfiguration &clientConfiguration) { std::cout << std::setfill('*') << std::setw(ASTERISK_FILL_WIDTH) << " " << std::endl; std::cout << "Welcome to the Amazon DynamoDB getting started demo." << std::endl; std::cout << std::setfill('*') << std::setw(ASTERISK_FILL_WIDTH) << " " << std::endl; Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration); // 2. Add a new movie. Aws::String title; float rating; int year; Aws::String plot; { title = askQuestion( "Enter the title of a movie you want to add to the table: "); year = askQuestionForInt("What year was it released? "); rating = askQuestionForFloatRange("On a scale of 1 - 10, how do you rate it? ", 1, 10); plot = askQuestion("Summarize the plot for me: "); Aws::DynamoDB::Model::PutItemRequest putItemRequest; putItemRequest.SetTableName(MOVIE_TABLE_NAME); putItemRequest.AddItem(YEAR_KEY, Aws::DynamoDB::Model::AttributeValue().SetN(year)); putItemRequest.AddItem(TITLE_KEY, Aws::DynamoDB::Model::AttributeValue().SetS(title)); // Create attribute for the info map. Aws::DynamoDB::Model::AttributeValue infoMapAttribute; std::shared_ptr<Aws::DynamoDB::Model::AttributeValue> ratingAttribute = Aws::MakeShared<Aws::DynamoDB::Model::AttributeValue>( ALLOCATION_TAG.c_str()); ratingAttribute->SetN(rating); infoMapAttribute.AddMEntry(RATING_KEY, ratingAttribute); std::shared_ptr<Aws::DynamoDB::Model::AttributeValue> plotAttribute = Aws::MakeShared<Aws::DynamoDB::Model::AttributeValue>( ALLOCATION_TAG.c_str()); plotAttribute->SetS(plot); infoMapAttribute.AddMEntry(PLOT_KEY, plotAttribute); putItemRequest.AddItem(INFO_KEY, infoMapAttribute); Aws::DynamoDB::Model::PutItemOutcome outcome = dynamoClient.PutItem( putItemRequest); if (!outcome.IsSuccess()) { std::cerr << "Failed to add an item: " << outcome.GetError().GetMessage() << std::endl; return false; } } std::cout << "\nAdded '" << title << "' to '" << MOVIE_TABLE_NAME << "'." << std::endl; // 3. Update the rating and plot of the movie by using an update expression. { rating = askQuestionForFloatRange( Aws::String("\nLet's update your movie.\nYou rated it ") + std::to_string(rating) + ", what new rating would you give it? ", 1, 10); plot = askQuestion(Aws::String("You summarized the plot as '") + plot + "'.\nWhat would you say now? "); Aws::DynamoDB::Model::UpdateItemRequest request; request.SetTableName(MOVIE_TABLE_NAME); request.AddKey(TITLE_KEY, Aws::DynamoDB::Model::AttributeValue().SetS(title)); request.AddKey(YEAR_KEY, Aws::DynamoDB::Model::AttributeValue().SetN(year)); std::stringstream expressionStream; expressionStream << "set " << INFO_KEY << "." << RATING_KEY << " =:r, " << INFO_KEY << "." << PLOT_KEY << " =:p"; request.SetUpdateExpression(expressionStream.str()); request.SetExpressionAttributeValues({ {":r", Aws::DynamoDB::Model::AttributeValue().SetN( rating)}, {":p", Aws::DynamoDB::Model::AttributeValue().SetS( plot)} }); request.SetReturnValues(Aws::DynamoDB::Model::ReturnValue::UPDATED_NEW); const Aws::DynamoDB::Model::UpdateItemOutcome &result = dynamoClient.UpdateItem( request); if (!result.IsSuccess()) { std::cerr << "Error updating movie " + result.GetError().GetMessage() << std::endl; return false; } } std::cout << "\nUpdated '" << title << "' with new attributes:" << std::endl; // 4. Put 250 movies in the table from moviedata.json. { std::cout << "Adding movies from a json file to the database." << std::endl; const size_t MAX_SIZE_FOR_BATCH_WRITE = 25; const size_t MOVIES_TO_WRITE = 10 * MAX_SIZE_FOR_BATCH_WRITE; Aws::String jsonString = getMovieJSON(); if (!jsonString.empty()) { Aws::Utils::Json::JsonValue json(jsonString); Aws::Utils::Array<Aws::Utils::Json::JsonView> movieJsons = json.View().AsArray(); Aws::Vector<Aws::DynamoDB::Model::WriteRequest> writeRequests; // To add movies with a cross-section of years, use an appropriate increment // value for iterating through the database. size_t increment = movieJsons.GetLength() / MOVIES_TO_WRITE; for (size_t i = 0; i < movieJsons.GetLength(); i += increment) { writeRequests.push_back(Aws::DynamoDB::Model::WriteRequest()); Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue> putItems = movieJsonViewToAttributeMap( movieJsons[i]); Aws::DynamoDB::Model::PutRequest putRequest; putRequest.SetItem(putItems); writeRequests.back().SetPutRequest(putRequest); if (writeRequests.size() == MAX_SIZE_FOR_BATCH_WRITE) { Aws::DynamoDB::Model::BatchWriteItemRequest request; request.AddRequestItems(MOVIE_TABLE_NAME, writeRequests); const Aws::DynamoDB::Model::BatchWriteItemOutcome &outcome = dynamoClient.BatchWriteItem( request); if (!outcome.IsSuccess()) { std::cerr << "Unable to batch write movie data: " << outcome.GetError().GetMessage() << std::endl; writeRequests.clear(); break; } else { std::cout << "Added batch of " << writeRequests.size() << " movies to the database." << std::endl; } writeRequests.clear(); } } } } std::cout << std::setfill('*') << std::setw(ASTERISK_FILL_WIDTH) << " " << std::endl; // 5. Get a movie by Key (partition + sort). { Aws::String titleToGet("King Kong"); Aws::String answer = askQuestion(Aws::String( "Let's move on...Would you like to get info about '" + titleToGet + "'? (y/n) ")); if (answer == "y") { Aws::DynamoDB::Model::GetItemRequest request; request.SetTableName(MOVIE_TABLE_NAME); request.AddKey(TITLE_KEY, Aws::DynamoDB::Model::AttributeValue().SetS(titleToGet)); request.AddKey(YEAR_KEY, Aws::DynamoDB::Model::AttributeValue().SetN(1933)); const Aws::DynamoDB::Model::GetItemOutcome &result = dynamoClient.GetItem( request); if (!result.IsSuccess()) { std::cerr << "Error " << result.GetError().GetMessage(); } else { const Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue> &item = result.GetResult().GetItem(); if (!item.empty()) { std::cout << "\nHere's what I found:" << std::endl; printMovieInfo(item); } else { std::cout << "\nThe movie was not found in the database." << std::endl; } } } } // 6. Use Query with a key condition expression to return all movies // released in a given year. Aws::String doAgain = "n"; do { Aws::DynamoDB::Model::QueryRequest req; req.SetTableName(MOVIE_TABLE_NAME); // "year" is a DynamoDB reserved keyword and must be replaced with an // expression attribute name. req.SetKeyConditionExpression("#dynobase_year = :valueToMatch"); req.SetExpressionAttributeNames({{"#dynobase_year", YEAR_KEY}}); int yearToMatch = askQuestionForIntRange( "\nLet's get a list of movies released in" " a given year. Enter a year between 1972 and 2018 ", 1972, 2018); Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue> attributeValues; attributeValues.emplace(":valueToMatch", Aws::DynamoDB::Model::AttributeValue().SetN( yearToMatch)); req.SetExpressionAttributeValues(attributeValues); const Aws::DynamoDB::Model::QueryOutcome &result = dynamoClient.Query(req); if (result.IsSuccess()) { const Aws::Vector<Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue>> &items = result.GetResult().GetItems(); if (!items.empty()) { std::cout << "\nThere were " << items.size() << " movies in the database from " << yearToMatch << "." << std::endl; for (const auto &item: items) { printMovieInfo(item); } doAgain = "n"; } else { std::cout << "\nNo movies from " << yearToMatch << " were found in the database" << std::endl; doAgain = askQuestion(Aws::String("Try another year? (y/n) ")); } } else { std::cerr << "Failed to Query items: " << result.GetError().GetMessage() << std::endl; } } while (doAgain == "y"); // 7. Use Scan to return movies released within a range of years. // Show how to paginate data using ExclusiveStartKey. (Scan + FilterExpression) { int startYear = askQuestionForIntRange("\nNow let's scan a range of years " "for movies in the database. Enter a start year: ", 1972, 2018); int endYear = askQuestionForIntRange("\nEnter an end year: ", startYear, 2018); Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue> exclusiveStartKey; do { Aws::DynamoDB::Model::ScanRequest scanRequest; scanRequest.SetTableName(MOVIE_TABLE_NAME); scanRequest.SetFilterExpression( "#dynobase_year >= :startYear AND #dynobase_year <= :endYear"); scanRequest.SetExpressionAttributeNames({{"#dynobase_year", YEAR_KEY}}); Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue> attributeValues; attributeValues.emplace(":startYear", Aws::DynamoDB::Model::AttributeValue().SetN( startYear)); attributeValues.emplace(":endYear", Aws::DynamoDB::Model::AttributeValue().SetN( endYear)); scanRequest.SetExpressionAttributeValues(attributeValues); if (!exclusiveStartKey.empty()) { scanRequest.SetExclusiveStartKey(exclusiveStartKey); } const Aws::DynamoDB::Model::ScanOutcome &result = dynamoClient.Scan( scanRequest); if (result.IsSuccess()) { const Aws::Vector<Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue>> &items = result.GetResult().GetItems(); if (!items.empty()) { std::stringstream stringStream; stringStream << "\nFound " << items.size() << " movies in one scan." << " How many would you like to see? "; size_t count = askQuestionForInt(stringStream.str()); for (size_t i = 0; i < count && i < items.size(); ++i) { printMovieInfo(items[i]); } } else { std::cout << "\nNo movies in the database between " << startYear << " and " << endYear << "." << std::endl; } exclusiveStartKey = result.GetResult().GetLastEvaluatedKey(); if (!exclusiveStartKey.empty()) { std::cout << "Not all movies were retrieved. Scanning for more." << std::endl; } else { std::cout << "All movies were retrieved with this scan." << std::endl; } } else { std::cerr << "Failed to Scan movies: " << result.GetError().GetMessage() << std::endl; } } while (!exclusiveStartKey.empty()); } // 8. Delete a movie. (DeleteItem) { std::stringstream stringStream; stringStream << "\nWould you like to delete the movie " << title << " from the database? (y/n) "; Aws::String answer = askQuestion(stringStream.str()); if (answer == "y") { Aws::DynamoDB::Model::DeleteItemRequest request; request.AddKey(YEAR_KEY, Aws::DynamoDB::Model::AttributeValue().SetN(year)); request.AddKey(TITLE_KEY, Aws::DynamoDB::Model::AttributeValue().SetS(title)); request.SetTableName(MOVIE_TABLE_NAME); const Aws::DynamoDB::Model::DeleteItemOutcome &result = dynamoClient.DeleteItem( request); if (result.IsSuccess()) { std::cout << "\nRemoved \"" << title << "\" from the database." << std::endl; } else { std::cerr << "Failed to delete the movie: " << result.GetError().GetMessage() << std::endl; } } } return true; } //! Routine to convert a JsonView object to an attribute map. /*! \sa movieJsonViewToAttributeMap() \param jsonView: Json view object. \return map: Map that can be used in a DynamoDB request. */ Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue> AwsDoc::DynamoDB::movieJsonViewToAttributeMap( const Aws::Utils::Json::JsonView &jsonView) { Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue> result; if (jsonView.KeyExists(YEAR_KEY)) { result[YEAR_KEY].SetN(jsonView.GetInteger(YEAR_KEY)); } if (jsonView.KeyExists(TITLE_KEY)) { result[TITLE_KEY].SetS(jsonView.GetString(TITLE_KEY)); } if (jsonView.KeyExists(INFO_KEY)) { Aws::Map<Aws::String, const std::shared_ptr<Aws::DynamoDB::Model::AttributeValue>> infoMap; Aws::Utils::Json::JsonView infoView = jsonView.GetObject(INFO_KEY); if (infoView.KeyExists(RATING_KEY)) { std::shared_ptr<Aws::DynamoDB::Model::AttributeValue> attributeValue = std::make_shared<Aws::DynamoDB::Model::AttributeValue>(); attributeValue->SetN(infoView.GetDouble(RATING_KEY)); infoMap.emplace(std::make_pair(RATING_KEY, attributeValue)); } if (infoView.KeyExists(PLOT_KEY)) { std::shared_ptr<Aws::DynamoDB::Model::AttributeValue> attributeValue = std::make_shared<Aws::DynamoDB::Model::AttributeValue>(); attributeValue->SetS(infoView.GetString(PLOT_KEY)); infoMap.emplace(std::make_pair(PLOT_KEY, attributeValue)); } result[INFO_KEY].SetM(infoMap); } return result; } //! Create a DynamoDB table to be used in sample code scenarios. /*! \sa createMoviesDynamoDBTable() \param clientConfiguration: AWS client configuration. \return bool: Function succeeded. */ bool AwsDoc::DynamoDB::createMoviesDynamoDBTable( const Aws::Client::ClientConfiguration &clientConfiguration) { Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration); bool movieTableAlreadyExisted = false; { Aws::DynamoDB::Model::CreateTableRequest request; Aws::DynamoDB::Model::AttributeDefinition yearAttributeDefinition; yearAttributeDefinition.SetAttributeName(YEAR_KEY); yearAttributeDefinition.SetAttributeType( Aws::DynamoDB::Model::ScalarAttributeType::N); request.AddAttributeDefinitions(yearAttributeDefinition); Aws::DynamoDB::Model::AttributeDefinition titleAttributeDefinition; yearAttributeDefinition.SetAttributeName(TITLE_KEY); yearAttributeDefinition.SetAttributeType( Aws::DynamoDB::Model::ScalarAttributeType::S); request.AddAttributeDefinitions(yearAttributeDefinition); Aws::DynamoDB::Model::KeySchemaElement yearKeySchema; yearKeySchema.WithAttributeName(YEAR_KEY).WithKeyType( Aws::DynamoDB::Model::KeyType::HASH); request.AddKeySchema(yearKeySchema); Aws::DynamoDB::Model::KeySchemaElement titleKeySchema; yearKeySchema.WithAttributeName(TITLE_KEY).WithKeyType( Aws::DynamoDB::Model::KeyType::RANGE); request.AddKeySchema(yearKeySchema); Aws::DynamoDB::Model::ProvisionedThroughput throughput; throughput.WithReadCapacityUnits( PROVISIONED_THROUGHPUT_UNITS).WithWriteCapacityUnits( PROVISIONED_THROUGHPUT_UNITS); request.SetProvisionedThroughput(throughput); request.SetTableName(MOVIE_TABLE_NAME); std::cout << "Creating table '" << MOVIE_TABLE_NAME << "'..." << std::endl; const Aws::DynamoDB::Model::CreateTableOutcome &result = dynamoClient.CreateTable( request); if (!result.IsSuccess()) { if (result.GetError().GetErrorType() == Aws::DynamoDB::DynamoDBErrors::RESOURCE_IN_USE) { std::cout << "Table already exists." << std::endl; movieTableAlreadyExisted = true; } else { std::cerr << "Failed to create table: " << result.GetError().GetMessage(); return false; } } } // Wait for table to become active. if (!movieTableAlreadyExisted) { std::cout << "Waiting for table '" << MOVIE_TABLE_NAME << "' to become active...." << std::endl; if (!AwsDoc::DynamoDB::waitTableActive(MOVIE_TABLE_NAME, clientConfiguration)) { return false; } std::cout << "Table '" << MOVIE_TABLE_NAME << "' created and active." << std::endl; } return true; } //! Delete the DynamoDB table used for sample code scenarios. /*! \sa deleteMoviesDynamoDBTable() \param clientConfiguration: AWS client configuration. \return bool: Function succeeded. */ bool AwsDoc::DynamoDB::deleteMoviesDynamoDBTable( const Aws::Client::ClientConfiguration &clientConfiguration) { Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration); Aws::DynamoDB::Model::DeleteTableRequest request; request.SetTableName(MOVIE_TABLE_NAME); const Aws::DynamoDB::Model::DeleteTableOutcome &result = dynamoClient.DeleteTable( request); if (result.IsSuccess()) { std::cout << "Your table \"" << result.GetResult().GetTableDescription().GetTableName() << " was deleted.\n"; } else { std::cerr << "Failed to delete table: " << result.GetError().GetMessage() << std::endl; } return result.IsSuccess(); } //! Query a newly created DynamoDB table until it is active. /*! \sa waitTableActive() \param waitTableActive: The DynamoDB table's name. \param dynamoClient: A DynamoDB client. \return bool: Function succeeded. */ bool AwsDoc::DynamoDB::waitTableActive(const Aws::String &tableName, const Aws::DynamoDB::DynamoDBClient &dynamoClient) { // Repeatedly call DescribeTable until table is ACTIVE. const int MAX_QUERIES = 20; Aws::DynamoDB::Model::DescribeTableRequest request; request.SetTableName(tableName); int count = 0; while (count < MAX_QUERIES) { const Aws::DynamoDB::Model::DescribeTableOutcome &result = dynamoClient.DescribeTable( request); if (result.IsSuccess()) { Aws::DynamoDB::Model::TableStatus status = result.GetResult().GetTable().GetTableStatus(); if (Aws::DynamoDB::Model::TableStatus::ACTIVE != status) { std::this_thread::sleep_for(std::chrono::seconds(1)); } else { return true; } } else { std::cerr << "Error DynamoDB::waitTableActive " << result.GetError().GetMessage() << std::endl; return false; } count++; } return false; }
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Para API obter detalhes, consulte os tópicos a seguir em AWS SDK for C++ APIReferência.
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Ações
O código de exemplo a seguir mostra como usar BatchExecuteStatement
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- SDKpara C++
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nota
Tem mais sobre GitHub. Encontre o exemplo completo e saiba como configurar e executar no Repositório de exemplos de código da AWS
. Use lotes de INSERT declarações para adicionar itens.
// 2. Add multiple movies using "Insert" statements. (BatchExecuteStatement) Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration); std::vector<Aws::String> titles; std::vector<float> ratings; std::vector<int> years; std::vector<Aws::String> plots; Aws::String doAgain = "n"; do { Aws::String aTitle = askQuestion( "Enter the title of a movie you want to add to the table: "); titles.push_back(aTitle); int aYear = askQuestionForInt("What year was it released? "); years.push_back(aYear); float aRating = askQuestionForFloatRange( "On a scale of 1 - 10, how do you rate it? ", 1, 10); ratings.push_back(aRating); Aws::String aPlot = askQuestion("Summarize the plot for me: "); plots.push_back(aPlot); doAgain = askQuestion(Aws::String("Would you like to add more movies? (y/n) ")); } while (doAgain == "y"); std::cout << "Adding " << titles.size() << (titles.size() == 1 ? " movie " : " movies ") << "to the table using a batch \"INSERT\" statement." << std::endl; { Aws::Vector<Aws::DynamoDB::Model::BatchStatementRequest> statements( titles.size()); std::stringstream sqlStream; sqlStream << "INSERT INTO \"" << MOVIE_TABLE_NAME << "\" VALUE {'" << TITLE_KEY << "': ?, '" << YEAR_KEY << "': ?, '" << INFO_KEY << "': ?}"; std::string sql(sqlStream.str()); for (size_t i = 0; i < statements.size(); ++i) { statements[i].SetStatement(sql); Aws::Vector<Aws::DynamoDB::Model::AttributeValue> attributes; attributes.push_back( Aws::DynamoDB::Model::AttributeValue().SetS(titles[i])); attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetN(years[i])); // Create attribute for the info map. Aws::DynamoDB::Model::AttributeValue infoMapAttribute; std::shared_ptr<Aws::DynamoDB::Model::AttributeValue> ratingAttribute = Aws::MakeShared<Aws::DynamoDB::Model::AttributeValue>( ALLOCATION_TAG.c_str()); ratingAttribute->SetN(ratings[i]); infoMapAttribute.AddMEntry(RATING_KEY, ratingAttribute); std::shared_ptr<Aws::DynamoDB::Model::AttributeValue> plotAttribute = Aws::MakeShared<Aws::DynamoDB::Model::AttributeValue>( ALLOCATION_TAG.c_str()); plotAttribute->SetS(plots[i]); infoMapAttribute.AddMEntry(PLOT_KEY, plotAttribute); attributes.push_back(infoMapAttribute); statements[i].SetParameters(attributes); } Aws::DynamoDB::Model::BatchExecuteStatementRequest request; request.SetStatements(statements); Aws::DynamoDB::Model::BatchExecuteStatementOutcome outcome = dynamoClient.BatchExecuteStatement( request); if (!outcome.IsSuccess()) { std::cerr << "Failed to add the movies: " << outcome.GetError().GetMessage() << std::endl; return false; } }
Use lotes de SELECT declarações para obter itens.
// 3. Get the data for multiple movies using "Select" statements. (BatchExecuteStatement) { Aws::Vector<Aws::DynamoDB::Model::BatchStatementRequest> statements( titles.size()); std::stringstream sqlStream; sqlStream << "SELECT * FROM \"" << MOVIE_TABLE_NAME << "\" WHERE " << TITLE_KEY << "=? and " << YEAR_KEY << "=?"; std::string sql(sqlStream.str()); for (size_t i = 0; i < statements.size(); ++i) { statements[i].SetStatement(sql); Aws::Vector<Aws::DynamoDB::Model::AttributeValue> attributes; attributes.push_back( Aws::DynamoDB::Model::AttributeValue().SetS(titles[i])); attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetN(years[i])); statements[i].SetParameters(attributes); } Aws::DynamoDB::Model::BatchExecuteStatementRequest request; request.SetStatements(statements); Aws::DynamoDB::Model::BatchExecuteStatementOutcome outcome = dynamoClient.BatchExecuteStatement( request); if (outcome.IsSuccess()) { const Aws::DynamoDB::Model::BatchExecuteStatementResult &result = outcome.GetResult(); const Aws::Vector<Aws::DynamoDB::Model::BatchStatementResponse> &responses = result.GetResponses(); for (const Aws::DynamoDB::Model::BatchStatementResponse &response: responses) { const Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue> &item = response.GetItem(); printMovieInfo(item); } } else { std::cerr << "Failed to retrieve the movie information: " << outcome.GetError().GetMessage() << std::endl; return false; } }
Use lotes de UPDATE declarações para atualizar itens.
// 4. Update the data for multiple movies using "Update" statements. (BatchExecuteStatement) for (size_t i = 0; i < titles.size(); ++i) { ratings[i] = askQuestionForFloatRange( Aws::String("\nLet's update your the movie, \"") + titles[i] + ".\nYou rated it " + std::to_string(ratings[i]) + ", what new rating would you give it? ", 1, 10); } std::cout << "Updating the movie with a batch \"UPDATE\" statement." << std::endl; { Aws::Vector<Aws::DynamoDB::Model::BatchStatementRequest> statements( titles.size()); std::stringstream sqlStream; sqlStream << "UPDATE \"" << MOVIE_TABLE_NAME << "\" SET " << INFO_KEY << "." << RATING_KEY << "=? WHERE " << TITLE_KEY << "=? AND " << YEAR_KEY << "=?"; std::string sql(sqlStream.str()); for (size_t i = 0; i < statements.size(); ++i) { statements[i].SetStatement(sql); Aws::Vector<Aws::DynamoDB::Model::AttributeValue> attributes; attributes.push_back( Aws::DynamoDB::Model::AttributeValue().SetN(ratings[i])); attributes.push_back( Aws::DynamoDB::Model::AttributeValue().SetS(titles[i])); attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetN(years[i])); statements[i].SetParameters(attributes); } Aws::DynamoDB::Model::BatchExecuteStatementRequest request; request.SetStatements(statements); Aws::DynamoDB::Model::BatchExecuteStatementOutcome outcome = dynamoClient.BatchExecuteStatement( request); if (!outcome.IsSuccess()) { std::cerr << "Failed to update movie information: " << outcome.GetError().GetMessage() << std::endl; return false; } }
Use lotes de DELETE declarações para excluir itens.
// 6. Delete multiple movies using "Delete" statements. (BatchExecuteStatement) { Aws::Vector<Aws::DynamoDB::Model::BatchStatementRequest> statements( titles.size()); std::stringstream sqlStream; sqlStream << "DELETE FROM \"" << MOVIE_TABLE_NAME << "\" WHERE " << TITLE_KEY << "=? and " << YEAR_KEY << "=?"; std::string sql(sqlStream.str()); for (size_t i = 0; i < statements.size(); ++i) { statements[i].SetStatement(sql); Aws::Vector<Aws::DynamoDB::Model::AttributeValue> attributes; attributes.push_back( Aws::DynamoDB::Model::AttributeValue().SetS(titles[i])); attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetN(years[i])); statements[i].SetParameters(attributes); } Aws::DynamoDB::Model::BatchExecuteStatementRequest request; request.SetStatements(statements); Aws::DynamoDB::Model::BatchExecuteStatementOutcome outcome = dynamoClient.BatchExecuteStatement( request); if (!outcome.IsSuccess()) { std::cerr << "Failed to delete the movies: " << outcome.GetError().GetMessage() << std::endl; return false; } }
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Para API obter detalhes, consulte BatchExecuteStatementem AWS SDK for C++ APIReferência.
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O código de exemplo a seguir mostra como usar BatchGetItem
.
- SDKpara C++
-
nota
Tem mais sobre GitHub. Encontre o exemplo completo e saiba como configurar e executar no Repositório de exemplos de código da AWS
. //! Batch get items from different Amazon DynamoDB tables. /*! \sa batchGetItem() \param clientConfiguration: AWS client configuration. \return bool: Function succeeded. */ bool AwsDoc::DynamoDB::batchGetItem( const Aws::Client::ClientConfiguration &clientConfiguration) { Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration); Aws::DynamoDB::Model::BatchGetItemRequest request; // Table1: Forum. Aws::String table1Name = "Forum"; Aws::DynamoDB::Model::KeysAndAttributes table1KeysAndAttributes; // Table1: Projection expression. table1KeysAndAttributes.SetProjectionExpression("#n, Category, Messages, #v"); // Table1: Expression attribute names. Aws::Http::HeaderValueCollection headerValueCollection; headerValueCollection.emplace("#n", "Name"); headerValueCollection.emplace("#v", "Views"); table1KeysAndAttributes.SetExpressionAttributeNames(headerValueCollection); // Table1: Set key name, type, and value to search. std::vector<Aws::String> nameValues = {"Amazon DynamoDB", "Amazon S3"}; for (const Aws::String &name: nameValues) { Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue> keys; Aws::DynamoDB::Model::AttributeValue key; key.SetS(name); keys.emplace("Name", key); table1KeysAndAttributes.AddKeys(keys); } Aws::Map<Aws::String, Aws::DynamoDB::Model::KeysAndAttributes> requestItems; requestItems.emplace(table1Name, table1KeysAndAttributes); // Table2: ProductCatalog. Aws::String table2Name = "ProductCatalog"; Aws::DynamoDB::Model::KeysAndAttributes table2KeysAndAttributes; table2KeysAndAttributes.SetProjectionExpression("Title, Price, Color"); // Table2: Set key name, type, and value to search. std::vector<Aws::String> idValues = {"102", "103", "201"}; for (const Aws::String &id: idValues) { Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue> keys; Aws::DynamoDB::Model::AttributeValue key; key.SetN(id); keys.emplace("Id", key); table2KeysAndAttributes.AddKeys(keys); } requestItems.emplace(table2Name, table2KeysAndAttributes); bool result = true; do { // Use a do loop to handle pagination. request.SetRequestItems(requestItems); const Aws::DynamoDB::Model::BatchGetItemOutcome &outcome = dynamoClient.BatchGetItem( request); if (outcome.IsSuccess()) { for (const auto &responsesMapEntry: outcome.GetResult().GetResponses()) { Aws::String tableName = responsesMapEntry.first; const Aws::Vector<Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue>> &tableResults = responsesMapEntry.second; std::cout << "Retrieved " << tableResults.size() << " responses for table '" << tableName << "'.\n" << std::endl; if (tableName == "Forum") { std::cout << "Name | Category | Message | Views" << std::endl; for (const Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue> &item: tableResults) { std::cout << item.at("Name").GetS() << " | "; std::cout << item.at("Category").GetS() << " | "; std::cout << (item.count("Message") == 0 ? "" : item.at( "Messages").GetN()) << " | "; std::cout << (item.count("Views") == 0 ? "" : item.at( "Views").GetN()) << std::endl; } } else { std::cout << "Title | Price | Color" << std::endl; for (const Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue> &item: tableResults) { std::cout << item.at("Title").GetS() << " | "; std::cout << (item.count("Price") == 0 ? "" : item.at( "Price").GetN()); if (item.count("Color")) { std::cout << " | "; for (const std::shared_ptr<Aws::DynamoDB::Model::AttributeValue> &listItem: item.at( "Color").GetL()) std::cout << listItem->GetS() << " "; } std::cout << std::endl; } } std::cout << std::endl; } // If necessary, repeat request for remaining items. requestItems = outcome.GetResult().GetUnprocessedKeys(); } else { std::cerr << "Batch get item failed: " << outcome.GetError().GetMessage() << std::endl; result = false; break; } } while (!requestItems.empty()); return result; }
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Para API obter detalhes, consulte BatchGetItemem AWS SDK for C++ APIReferência.
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O código de exemplo a seguir mostra como usar BatchWriteItem
.
- SDKpara C++
-
nota
Tem mais sobre GitHub. Encontre o exemplo completo e saiba como configurar e executar no Repositório de exemplos de código da AWS
. //! Batch write items from a JSON file. /*! \sa batchWriteItem() \param jsonFilePath: JSON file path. \param clientConfiguration: AWS client configuration. \return bool: Function succeeded. */ /* * The input for this routine is a JSON file that you can download from the following URL: * https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/SampleData.html. * * The JSON data uses the BatchWriteItem API request syntax. The JSON strings are * converted to AttributeValue objects. These AttributeValue objects will then generate * JSON strings when constructing the BatchWriteItem request, essentially outputting * their input. * * This is perhaps an artificial example, but it demonstrates the APIs. */ bool AwsDoc::DynamoDB::batchWriteItem(const Aws::String &jsonFilePath, const Aws::Client::ClientConfiguration &clientConfiguration) { std::ifstream fileStream(jsonFilePath); if (!fileStream) { std::cerr << "Error: could not open file '" << jsonFilePath << "'." << std::endl; } std::stringstream stringStream; stringStream << fileStream.rdbuf(); Aws::Utils::Json::JsonValue jsonValue(stringStream); Aws::DynamoDB::Model::BatchWriteItemRequest batchWriteItemRequest; Aws::Map<Aws::String, Aws::Utils::Json::JsonView> level1Map = jsonValue.View().GetAllObjects(); for (const auto &level1Entry: level1Map) { const Aws::Utils::Json::JsonView &entriesView = level1Entry.second; const Aws::String &tableName = level1Entry.first; // The JSON entries at this level are as follows: // key - table name // value - list of request objects if (!entriesView.IsListType()) { std::cerr << "Error: JSON file entry '" << tableName << "' is not a list." << std::endl; continue; } Aws::Utils::Array<Aws::Utils::Json::JsonView> entries = entriesView.AsArray(); Aws::Vector<Aws::DynamoDB::Model::WriteRequest> writeRequests; if (AwsDoc::DynamoDB::addWriteRequests(tableName, entries, writeRequests)) { batchWriteItemRequest.AddRequestItems(tableName, writeRequests); } } Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration); Aws::DynamoDB::Model::BatchWriteItemOutcome outcome = dynamoClient.BatchWriteItem( batchWriteItemRequest); if (outcome.IsSuccess()) { std::cout << "DynamoDB::BatchWriteItem was successful." << std::endl; } else { std::cerr << "Error with DynamoDB::BatchWriteItem. " << outcome.GetError().GetMessage() << std::endl; return false; } return outcome.IsSuccess(); } //! Convert requests in JSON format to a vector of WriteRequest objects. /*! \sa addWriteRequests() \param tableName: Name of the table for the write operations. \param requestsJson: Request data in JSON format. \param writeRequests: Vector to receive the WriteRequest objects. \return bool: Function succeeded. */ bool AwsDoc::DynamoDB::addWriteRequests(const Aws::String &tableName, const Aws::Utils::Array<Aws::Utils::Json::JsonView> &requestsJson, Aws::Vector<Aws::DynamoDB::Model::WriteRequest> &writeRequests) { for (size_t i = 0; i < requestsJson.GetLength(); ++i) { const Aws::Utils::Json::JsonView &requestsEntry = requestsJson[i]; if (!requestsEntry.IsObject()) { std::cerr << "Error: incorrect requestsEntry type " << requestsEntry.WriteReadable() << std::endl; return false; } Aws::Map<Aws::String, Aws::Utils::Json::JsonView> requestsMap = requestsEntry.GetAllObjects(); for (const auto &request: requestsMap) { const Aws::String &requestType = request.first; const Aws::Utils::Json::JsonView &requestJsonView = request.second; if (requestType == "PutRequest") { if (!requestJsonView.ValueExists("Item")) { std::cerr << "Error: item key missing for requests " << requestJsonView.WriteReadable() << std::endl; return false; } Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue> attributes; if (!getAttributeObjectsMap(requestJsonView.GetObject("Item"), attributes)) { std::cerr << "Error getting attributes " << requestJsonView.WriteReadable() << std::endl; return false; } Aws::DynamoDB::Model::PutRequest putRequest; putRequest.SetItem(attributes); writeRequests.push_back( Aws::DynamoDB::Model::WriteRequest().WithPutRequest( putRequest)); } else { std::cerr << "Error: unimplemented request type '" << requestType << "'." << std::endl; } } } return true; } //! Generate a map of AttributeValue objects from JSON records. /*! \sa getAttributeObjectsMap() \param jsonView: JSONView of attribute records. \param writeRequests: Map to receive the AttributeValue objects. \return bool: Function succeeded. */ bool AwsDoc::DynamoDB::getAttributeObjectsMap(const Aws::Utils::Json::JsonView &jsonView, Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue> &attributes) { Aws::Map<Aws::String, Aws::Utils::Json::JsonView> objectsMap = jsonView.GetAllObjects(); for (const auto &entry: objectsMap) { const Aws::String &attributeKey = entry.first; const Aws::Utils::Json::JsonView &attributeJsonView = entry.second; if (!attributeJsonView.IsObject()) { std::cerr << "Error: attribute not an object " << attributeJsonView.WriteReadable() << std::endl; return false; } attributes.emplace(attributeKey, Aws::DynamoDB::Model::AttributeValue(attributeJsonView)); } return true; }
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Para API obter detalhes, consulte BatchWriteItemem AWS SDK for C++ APIReferência.
-
O código de exemplo a seguir mostra como usar CreateTable
.
- SDKpara C++
-
nota
Tem mais sobre GitHub. Encontre o exemplo completo e saiba como configurar e executar no Repositório de exemplos de código da AWS
. //! Create an Amazon DynamoDB table. /*! \sa createTable() \param tableName: Name for the DynamoDB table. \param primaryKey: Primary key for the DynamoDB table. \param clientConfiguration: AWS client configuration. \return bool: Function succeeded. */ bool AwsDoc::DynamoDB::createTable(const Aws::String &tableName, const Aws::String &primaryKey, const Aws::Client::ClientConfiguration &clientConfiguration) { Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration); std::cout << "Creating table " << tableName << " with a simple primary key: \"" << primaryKey << "\"." << std::endl; Aws::DynamoDB::Model::CreateTableRequest request; Aws::DynamoDB::Model::AttributeDefinition hashKey; hashKey.SetAttributeName(primaryKey); hashKey.SetAttributeType(Aws::DynamoDB::Model::ScalarAttributeType::S); request.AddAttributeDefinitions(hashKey); Aws::DynamoDB::Model::KeySchemaElement keySchemaElement; keySchemaElement.WithAttributeName(primaryKey).WithKeyType( Aws::DynamoDB::Model::KeyType::HASH); request.AddKeySchema(keySchemaElement); Aws::DynamoDB::Model::ProvisionedThroughput throughput; throughput.WithReadCapacityUnits(5).WithWriteCapacityUnits(5); request.SetProvisionedThroughput(throughput); request.SetTableName(tableName); const Aws::DynamoDB::Model::CreateTableOutcome &outcome = dynamoClient.CreateTable( request); if (outcome.IsSuccess()) { std::cout << "Table \"" << outcome.GetResult().GetTableDescription().GetTableName() << " created!" << std::endl; } else { std::cerr << "Failed to create table: " << outcome.GetError().GetMessage() << std::endl; return false; } return waitTableActive(tableName, dynamoClient); }
Código que aguarda a tabela se tornar ativa.
//! Query a newly created DynamoDB table until it is active. /*! \sa waitTableActive() \param waitTableActive: The DynamoDB table's name. \param dynamoClient: A DynamoDB client. \return bool: Function succeeded. */ bool AwsDoc::DynamoDB::waitTableActive(const Aws::String &tableName, const Aws::DynamoDB::DynamoDBClient &dynamoClient) { // Repeatedly call DescribeTable until table is ACTIVE. const int MAX_QUERIES = 20; Aws::DynamoDB::Model::DescribeTableRequest request; request.SetTableName(tableName); int count = 0; while (count < MAX_QUERIES) { const Aws::DynamoDB::Model::DescribeTableOutcome &result = dynamoClient.DescribeTable( request); if (result.IsSuccess()) { Aws::DynamoDB::Model::TableStatus status = result.GetResult().GetTable().GetTableStatus(); if (Aws::DynamoDB::Model::TableStatus::ACTIVE != status) { std::this_thread::sleep_for(std::chrono::seconds(1)); } else { return true; } } else { std::cerr << "Error DynamoDB::waitTableActive " << result.GetError().GetMessage() << std::endl; return false; } count++; } return false; }
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Para API obter detalhes, consulte CreateTableem AWS SDK for C++ APIReferência.
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O código de exemplo a seguir mostra como usar DeleteItem
.
- SDKpara C++
-
nota
Tem mais sobre GitHub. Encontre o exemplo completo e saiba como configurar e executar no Repositório de exemplos de código da AWS
. //! Delete an item from an Amazon DynamoDB table. /*! \sa deleteItem() \param tableName: The table name. \param partitionKey: The partition key. \param partitionValue: The value for the partition key. \param clientConfiguration: AWS client configuration. \return bool: Function succeeded. */ bool AwsDoc::DynamoDB::deleteItem(const Aws::String &tableName, const Aws::String &partitionKey, const Aws::String &partitionValue, const Aws::Client::ClientConfiguration &clientConfiguration) { Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration); Aws::DynamoDB::Model::DeleteItemRequest request; request.AddKey(partitionKey, Aws::DynamoDB::Model::AttributeValue().SetS(partitionValue)); request.SetTableName(tableName); const Aws::DynamoDB::Model::DeleteItemOutcome &outcome = dynamoClient.DeleteItem( request); if (outcome.IsSuccess()) { std::cout << "Item \"" << partitionValue << "\" deleted!" << std::endl; } else { std::cerr << "Failed to delete item: " << outcome.GetError().GetMessage() << std::endl; return false; } return waitTableActive(tableName, dynamoClient); }
Código que aguarda a tabela se tornar ativa.
//! Query a newly created DynamoDB table until it is active. /*! \sa waitTableActive() \param waitTableActive: The DynamoDB table's name. \param dynamoClient: A DynamoDB client. \return bool: Function succeeded. */ bool AwsDoc::DynamoDB::waitTableActive(const Aws::String &tableName, const Aws::DynamoDB::DynamoDBClient &dynamoClient) { // Repeatedly call DescribeTable until table is ACTIVE. const int MAX_QUERIES = 20; Aws::DynamoDB::Model::DescribeTableRequest request; request.SetTableName(tableName); int count = 0; while (count < MAX_QUERIES) { const Aws::DynamoDB::Model::DescribeTableOutcome &result = dynamoClient.DescribeTable( request); if (result.IsSuccess()) { Aws::DynamoDB::Model::TableStatus status = result.GetResult().GetTable().GetTableStatus(); if (Aws::DynamoDB::Model::TableStatus::ACTIVE != status) { std::this_thread::sleep_for(std::chrono::seconds(1)); } else { return true; } } else { std::cerr << "Error DynamoDB::waitTableActive " << result.GetError().GetMessage() << std::endl; return false; } count++; } return false; }
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Para API obter detalhes, consulte DeleteItemem AWS SDK for C++ APIReferência.
-
O código de exemplo a seguir mostra como usar DeleteTable
.
- SDKpara C++
-
nota
Tem mais sobre GitHub. Encontre o exemplo completo e saiba como configurar e executar no Repositório de exemplos de código da AWS
. //! Delete an Amazon DynamoDB table. /*! \sa deleteTable() \param tableName: The DynamoDB table name. \param clientConfiguration: AWS client configuration. \return bool: Function succeeded. */ bool AwsDoc::DynamoDB::deleteTable(const Aws::String &tableName, const Aws::Client::ClientConfiguration &clientConfiguration) { Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration); Aws::DynamoDB::Model::DeleteTableRequest request; request.SetTableName(tableName); const Aws::DynamoDB::Model::DeleteTableOutcome &result = dynamoClient.DeleteTable( request); if (result.IsSuccess()) { std::cout << "Your table \"" << result.GetResult().GetTableDescription().GetTableName() << " was deleted.\n"; } else { std::cerr << "Failed to delete table: " << result.GetError().GetMessage() << std::endl; } return result.IsSuccess(); }
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Para API obter detalhes, consulte DeleteTableem AWS SDK for C++ APIReferência.
-
O código de exemplo a seguir mostra como usar DescribeTable
.
- SDKpara C++
-
nota
Tem mais sobre GitHub. Encontre o exemplo completo e saiba como configurar e executar no Repositório de exemplos de código da AWS
. //! Describe an Amazon DynamoDB table. /*! \sa describeTable() \param tableName: The DynamoDB table name. \param clientConfiguration: AWS client configuration. \return bool: Function succeeded. */ bool AwsDoc::DynamoDB::describeTable(const Aws::String &tableName, const Aws::Client::ClientConfiguration &clientConfiguration) { Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration); Aws::DynamoDB::Model::DescribeTableRequest request; request.SetTableName(tableName); const Aws::DynamoDB::Model::DescribeTableOutcome &outcome = dynamoClient.DescribeTable( request); if (outcome.IsSuccess()) { const Aws::DynamoDB::Model::TableDescription &td = outcome.GetResult().GetTable(); std::cout << "Table name : " << td.GetTableName() << std::endl; std::cout << "Table ARN : " << td.GetTableArn() << std::endl; std::cout << "Status : " << Aws::DynamoDB::Model::TableStatusMapper::GetNameForTableStatus( td.GetTableStatus()) << std::endl; std::cout << "Item count : " << td.GetItemCount() << std::endl; std::cout << "Size (bytes): " << td.GetTableSizeBytes() << std::endl; const Aws::DynamoDB::Model::ProvisionedThroughputDescription &ptd = td.GetProvisionedThroughput(); std::cout << "Throughput" << std::endl; std::cout << " Read Capacity : " << ptd.GetReadCapacityUnits() << std::endl; std::cout << " Write Capacity: " << ptd.GetWriteCapacityUnits() << std::endl; const Aws::Vector<Aws::DynamoDB::Model::AttributeDefinition> &ad = td.GetAttributeDefinitions(); std::cout << "Attributes" << std::endl; for (const auto &a: ad) std::cout << " " << a.GetAttributeName() << " (" << Aws::DynamoDB::Model::ScalarAttributeTypeMapper::GetNameForScalarAttributeType( a.GetAttributeType()) << ")" << std::endl; } else { std::cerr << "Failed to describe table: " << outcome.GetError().GetMessage(); } return outcome.IsSuccess(); }
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Para API obter detalhes, consulte DescribeTableem AWS SDK for C++ APIReferência.
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O código de exemplo a seguir mostra como usar ExecuteStatement
.
- SDKpara C++
-
nota
Tem mais sobre GitHub. Encontre o exemplo completo e saiba como configurar e executar no Repositório de exemplos de código da AWS
. Use uma INSERT declaração para adicionar um item.
Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration); // 2. Add a new movie using an "Insert" statement. (ExecuteStatement) Aws::String title; float rating; int year; Aws::String plot; { title = askQuestion( "Enter the title of a movie you want to add to the table: "); year = askQuestionForInt("What year was it released? "); rating = askQuestionForFloatRange("On a scale of 1 - 10, how do you rate it? ", 1, 10); plot = askQuestion("Summarize the plot for me: "); Aws::DynamoDB::Model::ExecuteStatementRequest request; std::stringstream sqlStream; sqlStream << "INSERT INTO \"" << MOVIE_TABLE_NAME << "\" VALUE {'" << TITLE_KEY << "': ?, '" << YEAR_KEY << "': ?, '" << INFO_KEY << "': ?}"; request.SetStatement(sqlStream.str()); // Create the parameter attributes. Aws::Vector<Aws::DynamoDB::Model::AttributeValue> attributes; attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetS(title)); attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetN(year)); Aws::DynamoDB::Model::AttributeValue infoMapAttribute; std::shared_ptr<Aws::DynamoDB::Model::AttributeValue> ratingAttribute = Aws::MakeShared<Aws::DynamoDB::Model::AttributeValue>( ALLOCATION_TAG.c_str()); ratingAttribute->SetN(rating); infoMapAttribute.AddMEntry(RATING_KEY, ratingAttribute); std::shared_ptr<Aws::DynamoDB::Model::AttributeValue> plotAttribute = Aws::MakeShared<Aws::DynamoDB::Model::AttributeValue>( ALLOCATION_TAG.c_str()); plotAttribute->SetS(plot); infoMapAttribute.AddMEntry(PLOT_KEY, plotAttribute); attributes.push_back(infoMapAttribute); request.SetParameters(attributes); Aws::DynamoDB::Model::ExecuteStatementOutcome outcome = dynamoClient.ExecuteStatement( request); if (!outcome.IsSuccess()) { std::cerr << "Failed to add a movie: " << outcome.GetError().GetMessage() << std::endl; return false; } }
Use uma SELECT declaração para obter um item.
// 3. Get the data for the movie using a "Select" statement. (ExecuteStatement) { Aws::DynamoDB::Model::ExecuteStatementRequest request; std::stringstream sqlStream; sqlStream << "SELECT * FROM \"" << MOVIE_TABLE_NAME << "\" WHERE " << TITLE_KEY << "=? and " << YEAR_KEY << "=?"; request.SetStatement(sqlStream.str()); Aws::Vector<Aws::DynamoDB::Model::AttributeValue> attributes; attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetS(title)); attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetN(year)); request.SetParameters(attributes); Aws::DynamoDB::Model::ExecuteStatementOutcome outcome = dynamoClient.ExecuteStatement( request); if (!outcome.IsSuccess()) { std::cerr << "Failed to retrieve movie information: " << outcome.GetError().GetMessage() << std::endl; return false; } else { // Print the retrieved movie information. const Aws::DynamoDB::Model::ExecuteStatementResult &result = outcome.GetResult(); const Aws::Vector<Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue>> &items = result.GetItems(); if (items.size() == 1) { printMovieInfo(items[0]); } else { std::cerr << "Error: " << items.size() << " movies were retrieved. " << " There should be only one movie." << std::endl; } } }
Use uma UPDATE declaração para atualizar um item.
// 4. Update the data for the movie using an "Update" statement. (ExecuteStatement) { rating = askQuestionForFloatRange( Aws::String("\nLet's update your movie.\nYou rated it ") + std::to_string(rating) + ", what new rating would you give it? ", 1, 10); Aws::DynamoDB::Model::ExecuteStatementRequest request; std::stringstream sqlStream; sqlStream << "UPDATE \"" << MOVIE_TABLE_NAME << "\" SET " << INFO_KEY << "." << RATING_KEY << "=? WHERE " << TITLE_KEY << "=? AND " << YEAR_KEY << "=?"; request.SetStatement(sqlStream.str()); Aws::Vector<Aws::DynamoDB::Model::AttributeValue> attributes; attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetN(rating)); attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetS(title)); attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetN(year)); request.SetParameters(attributes); Aws::DynamoDB::Model::ExecuteStatementOutcome outcome = dynamoClient.ExecuteStatement( request); if (!outcome.IsSuccess()) { std::cerr << "Failed to update a movie: " << outcome.GetError().GetMessage(); return false; } }
Use uma DELETE declaração para excluir um item.
// 6. Delete the movie using a "Delete" statement. (ExecuteStatement) { Aws::DynamoDB::Model::ExecuteStatementRequest request; std::stringstream sqlStream; sqlStream << "DELETE FROM \"" << MOVIE_TABLE_NAME << "\" WHERE " << TITLE_KEY << "=? and " << YEAR_KEY << "=?"; request.SetStatement(sqlStream.str()); Aws::Vector<Aws::DynamoDB::Model::AttributeValue> attributes; attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetS(title)); attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetN(year)); request.SetParameters(attributes); Aws::DynamoDB::Model::ExecuteStatementOutcome outcome = dynamoClient.ExecuteStatement( request); if (!outcome.IsSuccess()) { std::cerr << "Failed to delete the movie: " << outcome.GetError().GetMessage() << std::endl; return false; } }
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Para API obter detalhes, consulte ExecuteStatementem AWS SDK for C++ APIReferência.
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O código de exemplo a seguir mostra como usar GetItem
.
- SDKpara C++
-
nota
Tem mais sobre GitHub. Encontre o exemplo completo e saiba como configurar e executar no Repositório de exemplos de código da AWS
. //! Get an item from an Amazon DynamoDB table. /*! \sa getItem() \param tableName: The table name. \param partitionKey: The partition key. \param partitionValue: The value for the partition key. \param clientConfiguration: AWS client configuration. \return bool: Function succeeded. */ bool AwsDoc::DynamoDB::getItem(const Aws::String &tableName, const Aws::String &partitionKey, const Aws::String &partitionValue, const Aws::Client::ClientConfiguration &clientConfiguration) { Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration); Aws::DynamoDB::Model::GetItemRequest request; // Set up the request. request.SetTableName(tableName); request.AddKey(partitionKey, Aws::DynamoDB::Model::AttributeValue().SetS(partitionValue)); // Retrieve the item's fields and values. const Aws::DynamoDB::Model::GetItemOutcome &outcome = dynamoClient.GetItem(request); if (outcome.IsSuccess()) { // Reference the retrieved fields/values. const Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue> &item = outcome.GetResult().GetItem(); if (!item.empty()) { // Output each retrieved field and its value. for (const auto &i: item) std::cout << "Values: " << i.first << ": " << i.second.GetS() << std::endl; } else { std::cout << "No item found with the key " << partitionKey << std::endl; } } else { std::cerr << "Failed to get item: " << outcome.GetError().GetMessage(); } return outcome.IsSuccess(); }
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Para API obter detalhes, consulte GetItemem AWS SDK for C++ APIReferência.
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O código de exemplo a seguir mostra como usar ListTables
.
- SDKpara C++
-
nota
Tem mais sobre GitHub. Encontre o exemplo completo e saiba como configurar e executar no Repositório de exemplos de código da AWS
. //! List the Amazon DynamoDB tables for the current AWS account. /*! \sa listTables() \param clientConfiguration: AWS client configuration. \return bool: Function succeeded. */ bool AwsDoc::DynamoDB::listTables( const Aws::Client::ClientConfiguration &clientConfiguration) { Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration); Aws::DynamoDB::Model::ListTablesRequest listTablesRequest; listTablesRequest.SetLimit(50); do { const Aws::DynamoDB::Model::ListTablesOutcome &outcome = dynamoClient.ListTables( listTablesRequest); if (!outcome.IsSuccess()) { std::cout << "Error: " << outcome.GetError().GetMessage() << std::endl; return false; } for (const auto &tableName: outcome.GetResult().GetTableNames()) std::cout << tableName << std::endl; listTablesRequest.SetExclusiveStartTableName( outcome.GetResult().GetLastEvaluatedTableName()); } while (!listTablesRequest.GetExclusiveStartTableName().empty()); return true; }
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Para API obter detalhes, consulte ListTablesem AWS SDK for C++ APIReferência.
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O código de exemplo a seguir mostra como usar PutItem
.
- SDKpara C++
-
nota
Tem mais sobre GitHub. Encontre o exemplo completo e saiba como configurar e executar no Repositório de exemplos de código da AWS
. //! Put an item in an Amazon DynamoDB table. /*! \sa putItem() \param tableName: The table name. \param artistKey: The artist key. This is the partition key for the table. \param artistValue: The artist value. \param albumTitleKey: The album title key. \param albumTitleValue: The album title value. \param awardsKey: The awards key. \param awardsValue: The awards value. \param songTitleKey: The song title key. \param songTitleValue: The song title value. \param clientConfiguration: AWS client configuration. \return bool: Function succeeded. */ bool AwsDoc::DynamoDB::putItem(const Aws::String &tableName, const Aws::String &artistKey, const Aws::String &artistValue, const Aws::String &albumTitleKey, const Aws::String &albumTitleValue, const Aws::String &awardsKey, const Aws::String &awardsValue, const Aws::String &songTitleKey, const Aws::String &songTitleValue, const Aws::Client::ClientConfiguration &clientConfiguration) { Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration); Aws::DynamoDB::Model::PutItemRequest putItemRequest; putItemRequest.SetTableName(tableName); putItemRequest.AddItem(artistKey, Aws::DynamoDB::Model::AttributeValue().SetS( artistValue)); // This is the hash key. putItemRequest.AddItem(albumTitleKey, Aws::DynamoDB::Model::AttributeValue().SetS( albumTitleValue)); putItemRequest.AddItem(awardsKey, Aws::DynamoDB::Model::AttributeValue().SetS(awardsValue)); putItemRequest.AddItem(songTitleKey, Aws::DynamoDB::Model::AttributeValue().SetS(songTitleValue)); const Aws::DynamoDB::Model::PutItemOutcome outcome = dynamoClient.PutItem( putItemRequest); if (outcome.IsSuccess()) { std::cout << "Successfully added Item!" << std::endl; } else { std::cerr << outcome.GetError().GetMessage() << std::endl; return false; } return waitTableActive(tableName, dynamoClient); }
Código que aguarda a tabela se tornar ativa.
//! Query a newly created DynamoDB table until it is active. /*! \sa waitTableActive() \param waitTableActive: The DynamoDB table's name. \param dynamoClient: A DynamoDB client. \return bool: Function succeeded. */ bool AwsDoc::DynamoDB::waitTableActive(const Aws::String &tableName, const Aws::DynamoDB::DynamoDBClient &dynamoClient) { // Repeatedly call DescribeTable until table is ACTIVE. const int MAX_QUERIES = 20; Aws::DynamoDB::Model::DescribeTableRequest request; request.SetTableName(tableName); int count = 0; while (count < MAX_QUERIES) { const Aws::DynamoDB::Model::DescribeTableOutcome &result = dynamoClient.DescribeTable( request); if (result.IsSuccess()) { Aws::DynamoDB::Model::TableStatus status = result.GetResult().GetTable().GetTableStatus(); if (Aws::DynamoDB::Model::TableStatus::ACTIVE != status) { std::this_thread::sleep_for(std::chrono::seconds(1)); } else { return true; } } else { std::cerr << "Error DynamoDB::waitTableActive " << result.GetError().GetMessage() << std::endl; return false; } count++; } return false; }
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Para API obter detalhes, consulte PutItemem AWS SDK for C++ APIReferência.
-
O código de exemplo a seguir mostra como usar Query
.
- SDKpara C++
-
nota
Tem mais sobre GitHub. Encontre o exemplo completo e saiba como configurar e executar no Repositório de exemplos de código da AWS
. //! Perform a query on an Amazon DynamoDB Table and retrieve items. /*! \sa queryItem() \param tableName: The table name. \param partitionKey: The partition key. \param partitionValue: The value for the partition key. \param projectionExpression: The projections expression, which is ignored if empty. \param clientConfiguration: AWS client configuration. \return bool: Function succeeded. */ /* * The partition key attribute is searched with the specified value. By default, all fields and values * contained in the item are returned. If an optional projection expression is * specified on the command line, only the specified fields and values are * returned. */ bool AwsDoc::DynamoDB::queryItems(const Aws::String &tableName, const Aws::String &partitionKey, const Aws::String &partitionValue, const Aws::String &projectionExpression, const Aws::Client::ClientConfiguration &clientConfiguration) { Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration); Aws::DynamoDB::Model::QueryRequest request; request.SetTableName(tableName); if (!projectionExpression.empty()) { request.SetProjectionExpression(projectionExpression); } // Set query key condition expression. request.SetKeyConditionExpression(partitionKey + "= :valueToMatch"); // Set Expression AttributeValues. Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue> attributeValues; attributeValues.emplace(":valueToMatch", partitionValue); request.SetExpressionAttributeValues(attributeValues); bool result = true; // "exclusiveStartKey" is used for pagination. Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue> exclusiveStartKey; do { if (!exclusiveStartKey.empty()) { request.SetExclusiveStartKey(exclusiveStartKey); exclusiveStartKey.clear(); } // Perform Query operation. const Aws::DynamoDB::Model::QueryOutcome &outcome = dynamoClient.Query(request); if (outcome.IsSuccess()) { // Reference the retrieved items. const Aws::Vector<Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue>> &items = outcome.GetResult().GetItems(); if (!items.empty()) { std::cout << "Number of items retrieved from Query: " << items.size() << std::endl; // Iterate each item and print. for (const auto &item: items) { std::cout << "******************************************************" << std::endl; // Output each retrieved field and its value. for (const auto &i: item) std::cout << i.first << ": " << i.second.GetS() << std::endl; } } else { std::cout << "No item found in table: " << tableName << std::endl; } exclusiveStartKey = outcome.GetResult().GetLastEvaluatedKey(); } else { std::cerr << "Failed to Query items: " << outcome.GetError().GetMessage(); result = false; break; } } while (!exclusiveStartKey.empty()); return result; }
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Para API obter detalhes, consulte Consulta na AWS SDK for C++ APIreferência.
-
O código de exemplo a seguir mostra como usar Scan
.
- SDKpara C++
-
nota
Tem mais sobre GitHub. Encontre o exemplo completo e saiba como configurar e executar no Repositório de exemplos de código da AWS
. //! Scan an Amazon DynamoDB table. /*! \sa scanTable() \param tableName: Name for the DynamoDB table. \param projectionExpression: An optional projection expression, ignored if empty. \param clientConfiguration: AWS client configuration. \return bool: Function succeeded. */ bool AwsDoc::DynamoDB::scanTable(const Aws::String &tableName, const Aws::String &projectionExpression, const Aws::Client::ClientConfiguration &clientConfiguration) { Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration); Aws::DynamoDB::Model::ScanRequest request; request.SetTableName(tableName); if (!projectionExpression.empty()) request.SetProjectionExpression(projectionExpression); Aws::Vector<Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue>> all_items; Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue> last_evaluated_key; // Used for pagination; do { if (!last_evaluated_key.empty()) { request.SetExclusiveStartKey(last_evaluated_key); } const Aws::DynamoDB::Model::ScanOutcome &outcome = dynamoClient.Scan(request); if (outcome.IsSuccess()) { // Reference the retrieved items. const Aws::Vector<Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue>> &items = outcome.GetResult().GetItems(); all_items.insert(all_items.end(), items.begin(), items.end()); last_evaluated_key = outcome.GetResult().GetLastEvaluatedKey(); } else { std::cerr << "Failed to Scan items: " << outcome.GetError().GetMessage() << std::endl; return false; } } while (!last_evaluated_key.empty()); if (!all_items.empty()) { std::cout << "Number of items retrieved from scan: " << all_items.size() << std::endl; // Iterate each item and print. for (const Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue> &itemMap: all_items) { std::cout << "******************************************************" << std::endl; // Output each retrieved field and its value. for (const auto &itemEntry: itemMap) std::cout << itemEntry.first << ": " << itemEntry.second.GetS() << std::endl; } } else { std::cout << "No items found in table: " << tableName << std::endl; } return true; }
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Para API obter detalhes, consulte Digitalizar em AWS SDK for C++ APIreferência.
-
O código de exemplo a seguir mostra como usar UpdateItem
.
- SDKpara C++
-
nota
Tem mais sobre GitHub. Encontre o exemplo completo e saiba como configurar e executar no Repositório de exemplos de código da AWS
. //! Update an Amazon DynamoDB table item. /*! \sa updateItem() \param tableName: The table name. \param partitionKey: The partition key. \param partitionValue: The value for the partition key. \param attributeKey: The key for the attribute to be updated. \param attributeValue: The value for the attribute to be updated. \param clientConfiguration: AWS client configuration. \return bool: Function succeeded. */ /* * The example code only sets/updates an attribute value. It processes * the attribute value as a string, even if the value could be interpreted * as a number. Also, the example code does not remove an existing attribute * from the key value. */ bool AwsDoc::DynamoDB::updateItem(const Aws::String &tableName, const Aws::String &partitionKey, const Aws::String &partitionValue, const Aws::String &attributeKey, const Aws::String &attributeValue, const Aws::Client::ClientConfiguration &clientConfiguration) { Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration); // *** Define UpdateItem request arguments. // Define TableName argument. Aws::DynamoDB::Model::UpdateItemRequest request; request.SetTableName(tableName); // Define KeyName argument. Aws::DynamoDB::Model::AttributeValue attribValue; attribValue.SetS(partitionValue); request.AddKey(partitionKey, attribValue); // Construct the SET update expression argument. Aws::String update_expression("SET #a = :valueA"); request.SetUpdateExpression(update_expression); // Construct attribute name argument. Aws::Map<Aws::String, Aws::String> expressionAttributeNames; expressionAttributeNames["#a"] = attributeKey; request.SetExpressionAttributeNames(expressionAttributeNames); // Construct attribute value argument. Aws::DynamoDB::Model::AttributeValue attributeUpdatedValue; attributeUpdatedValue.SetS(attributeValue); Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue> expressionAttributeValues; expressionAttributeValues[":valueA"] = attributeUpdatedValue; request.SetExpressionAttributeValues(expressionAttributeValues); // Update the item. const Aws::DynamoDB::Model::UpdateItemOutcome &outcome = dynamoClient.UpdateItem( request); if (outcome.IsSuccess()) { std::cout << "Item was updated" << std::endl; } else { std::cerr << outcome.GetError().GetMessage() << std::endl; return false; } return waitTableActive(tableName, dynamoClient); }
Código que aguarda a tabela se tornar ativa.
//! Query a newly created DynamoDB table until it is active. /*! \sa waitTableActive() \param waitTableActive: The DynamoDB table's name. \param dynamoClient: A DynamoDB client. \return bool: Function succeeded. */ bool AwsDoc::DynamoDB::waitTableActive(const Aws::String &tableName, const Aws::DynamoDB::DynamoDBClient &dynamoClient) { // Repeatedly call DescribeTable until table is ACTIVE. const int MAX_QUERIES = 20; Aws::DynamoDB::Model::DescribeTableRequest request; request.SetTableName(tableName); int count = 0; while (count < MAX_QUERIES) { const Aws::DynamoDB::Model::DescribeTableOutcome &result = dynamoClient.DescribeTable( request); if (result.IsSuccess()) { Aws::DynamoDB::Model::TableStatus status = result.GetResult().GetTable().GetTableStatus(); if (Aws::DynamoDB::Model::TableStatus::ACTIVE != status) { std::this_thread::sleep_for(std::chrono::seconds(1)); } else { return true; } } else { std::cerr << "Error DynamoDB::waitTableActive " << result.GetError().GetMessage() << std::endl; return false; } count++; } return false; }
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Para API obter detalhes, consulte UpdateItemem AWS SDK for C++ APIReferência.
-
O código de exemplo a seguir mostra como usar UpdateTable
.
- SDKpara C++
-
nota
Tem mais sobre GitHub. Encontre o exemplo completo e saiba como configurar e executar no Repositório de exemplos de código da AWS
. //! Update a DynamoDB table. /*! \sa updateTable() \param tableName: Name for the DynamoDB table. \param readCapacity: Provisioned read capacity. \param writeCapacity: Provisioned write capacity. \param clientConfiguration: AWS client configuration. \return bool: Function succeeded. */ bool AwsDoc::DynamoDB::updateTable(const Aws::String &tableName, long long readCapacity, long long writeCapacity, const Aws::Client::ClientConfiguration &clientConfiguration) { Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration); std::cout << "Updating " << tableName << " with new provisioned throughput values" << std::endl; std::cout << "Read capacity : " << readCapacity << std::endl; std::cout << "Write capacity: " << writeCapacity << std::endl; Aws::DynamoDB::Model::UpdateTableRequest request; Aws::DynamoDB::Model::ProvisionedThroughput provisionedThroughput; provisionedThroughput.WithReadCapacityUnits(readCapacity).WithWriteCapacityUnits( writeCapacity); request.WithProvisionedThroughput(provisionedThroughput).WithTableName(tableName); const Aws::DynamoDB::Model::UpdateTableOutcome &outcome = dynamoClient.UpdateTable( request); if (outcome.IsSuccess()) { std::cout << "Successfully updated the table." << std::endl; } else { const Aws::DynamoDB::DynamoDBError &error = outcome.GetError(); if (error.GetErrorType() == Aws::DynamoDB::DynamoDBErrors::VALIDATION && error.GetMessage().find("The provisioned throughput for the table will not change") != std::string::npos) { std::cout << "The provisioned throughput for the table will not change." << std::endl; } else { std::cerr << outcome.GetError().GetMessage() << std::endl; return false; } } return waitTableActive(tableName, dynamoClient); }
Código que aguarda a tabela se tornar ativa.
//! Query a newly created DynamoDB table until it is active. /*! \sa waitTableActive() \param waitTableActive: The DynamoDB table's name. \param dynamoClient: A DynamoDB client. \return bool: Function succeeded. */ bool AwsDoc::DynamoDB::waitTableActive(const Aws::String &tableName, const Aws::DynamoDB::DynamoDBClient &dynamoClient) { // Repeatedly call DescribeTable until table is ACTIVE. const int MAX_QUERIES = 20; Aws::DynamoDB::Model::DescribeTableRequest request; request.SetTableName(tableName); int count = 0; while (count < MAX_QUERIES) { const Aws::DynamoDB::Model::DescribeTableOutcome &result = dynamoClient.DescribeTable( request); if (result.IsSuccess()) { Aws::DynamoDB::Model::TableStatus status = result.GetResult().GetTable().GetTableStatus(); if (Aws::DynamoDB::Model::TableStatus::ACTIVE != status) { std::this_thread::sleep_for(std::chrono::seconds(1)); } else { return true; } } else { std::cerr << "Error DynamoDB::waitTableActive " << result.GetError().GetMessage() << std::endl; return false; } count++; } return false; }
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Para API obter detalhes, consulte UpdateTableem AWS SDK for C++ APIReferência.
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Cenários
O exemplo de código a seguir mostra como criar uma aplicação com tecnologia sem servidor que permite que os usuários gerenciem fotos usando rótulos.
- SDKpara C++
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Mostra como desenvolver uma aplicação de gerenciamento de ativos fotográficos que detecta rótulos em imagens usando o Amazon Rekognition e os armazena para recuperação posterior.
Para obter o código-fonte completo e instruções sobre como configurar e executar, veja o exemplo completo em GitHub
. Para uma análise detalhada da origem desse exemplo, veja a publicação na Comunidade da AWS
. Serviços utilizados neste exemplo
APIGateway
DynamoDB
Lambda
Amazon Rekognition
Amazon S3
Amazon SNS
O exemplo de código a seguir mostra como:
Obtenha um lote de itens executando várias SELECT instruções.
Adicione um lote de itens executando várias INSERT instruções.
Atualize um lote de itens executando várias UPDATE instruções.
Exclua um lote de itens executando várias DELETE instruções.
- SDKpara C++
-
nota
Tem mais sobre GitHub. Encontre o exemplo completo e saiba como configurar e executar no Repositório de exemplos de código da AWS
. Aws::Client::ClientConfiguration clientConfig; // 1. Create a table. (CreateTable) if (AwsDoc::DynamoDB::createMoviesDynamoDBTable(clientConfig)) { AwsDoc::DynamoDB::partiqlBatchExecuteScenario(clientConfig); // 7. Delete the table. (DeleteTable) AwsDoc::DynamoDB::deleteMoviesDynamoDBTable(clientConfig); } //! Scenario to modify and query a DynamoDB table using PartiQL batch statements. /*! \sa partiqlBatchExecuteScenario() \param clientConfiguration: AWS client configuration. \return bool: Function succeeded. */ bool AwsDoc::DynamoDB::partiqlBatchExecuteScenario( const Aws::Client::ClientConfiguration &clientConfiguration) { // 2. Add multiple movies using "Insert" statements. (BatchExecuteStatement) Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration); std::vector<Aws::String> titles; std::vector<float> ratings; std::vector<int> years; std::vector<Aws::String> plots; Aws::String doAgain = "n"; do { Aws::String aTitle = askQuestion( "Enter the title of a movie you want to add to the table: "); titles.push_back(aTitle); int aYear = askQuestionForInt("What year was it released? "); years.push_back(aYear); float aRating = askQuestionForFloatRange( "On a scale of 1 - 10, how do you rate it? ", 1, 10); ratings.push_back(aRating); Aws::String aPlot = askQuestion("Summarize the plot for me: "); plots.push_back(aPlot); doAgain = askQuestion(Aws::String("Would you like to add more movies? (y/n) ")); } while (doAgain == "y"); std::cout << "Adding " << titles.size() << (titles.size() == 1 ? " movie " : " movies ") << "to the table using a batch \"INSERT\" statement." << std::endl; { Aws::Vector<Aws::DynamoDB::Model::BatchStatementRequest> statements( titles.size()); std::stringstream sqlStream; sqlStream << "INSERT INTO \"" << MOVIE_TABLE_NAME << "\" VALUE {'" << TITLE_KEY << "': ?, '" << YEAR_KEY << "': ?, '" << INFO_KEY << "': ?}"; std::string sql(sqlStream.str()); for (size_t i = 0; i < statements.size(); ++i) { statements[i].SetStatement(sql); Aws::Vector<Aws::DynamoDB::Model::AttributeValue> attributes; attributes.push_back( Aws::DynamoDB::Model::AttributeValue().SetS(titles[i])); attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetN(years[i])); // Create attribute for the info map. Aws::DynamoDB::Model::AttributeValue infoMapAttribute; std::shared_ptr<Aws::DynamoDB::Model::AttributeValue> ratingAttribute = Aws::MakeShared<Aws::DynamoDB::Model::AttributeValue>( ALLOCATION_TAG.c_str()); ratingAttribute->SetN(ratings[i]); infoMapAttribute.AddMEntry(RATING_KEY, ratingAttribute); std::shared_ptr<Aws::DynamoDB::Model::AttributeValue> plotAttribute = Aws::MakeShared<Aws::DynamoDB::Model::AttributeValue>( ALLOCATION_TAG.c_str()); plotAttribute->SetS(plots[i]); infoMapAttribute.AddMEntry(PLOT_KEY, plotAttribute); attributes.push_back(infoMapAttribute); statements[i].SetParameters(attributes); } Aws::DynamoDB::Model::BatchExecuteStatementRequest request; request.SetStatements(statements); Aws::DynamoDB::Model::BatchExecuteStatementOutcome outcome = dynamoClient.BatchExecuteStatement( request); if (!outcome.IsSuccess()) { std::cerr << "Failed to add the movies: " << outcome.GetError().GetMessage() << std::endl; return false; } } std::cout << "Retrieving the movie data with a batch \"SELECT\" statement." << std::endl; // 3. Get the data for multiple movies using "Select" statements. (BatchExecuteStatement) { Aws::Vector<Aws::DynamoDB::Model::BatchStatementRequest> statements( titles.size()); std::stringstream sqlStream; sqlStream << "SELECT * FROM \"" << MOVIE_TABLE_NAME << "\" WHERE " << TITLE_KEY << "=? and " << YEAR_KEY << "=?"; std::string sql(sqlStream.str()); for (size_t i = 0; i < statements.size(); ++i) { statements[i].SetStatement(sql); Aws::Vector<Aws::DynamoDB::Model::AttributeValue> attributes; attributes.push_back( Aws::DynamoDB::Model::AttributeValue().SetS(titles[i])); attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetN(years[i])); statements[i].SetParameters(attributes); } Aws::DynamoDB::Model::BatchExecuteStatementRequest request; request.SetStatements(statements); Aws::DynamoDB::Model::BatchExecuteStatementOutcome outcome = dynamoClient.BatchExecuteStatement( request); if (outcome.IsSuccess()) { const Aws::DynamoDB::Model::BatchExecuteStatementResult &result = outcome.GetResult(); const Aws::Vector<Aws::DynamoDB::Model::BatchStatementResponse> &responses = result.GetResponses(); for (const Aws::DynamoDB::Model::BatchStatementResponse &response: responses) { const Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue> &item = response.GetItem(); printMovieInfo(item); } } else { std::cerr << "Failed to retrieve the movie information: " << outcome.GetError().GetMessage() << std::endl; return false; } } // 4. Update the data for multiple movies using "Update" statements. (BatchExecuteStatement) for (size_t i = 0; i < titles.size(); ++i) { ratings[i] = askQuestionForFloatRange( Aws::String("\nLet's update your the movie, \"") + titles[i] + ".\nYou rated it " + std::to_string(ratings[i]) + ", what new rating would you give it? ", 1, 10); } std::cout << "Updating the movie with a batch \"UPDATE\" statement." << std::endl; { Aws::Vector<Aws::DynamoDB::Model::BatchStatementRequest> statements( titles.size()); std::stringstream sqlStream; sqlStream << "UPDATE \"" << MOVIE_TABLE_NAME << "\" SET " << INFO_KEY << "." << RATING_KEY << "=? WHERE " << TITLE_KEY << "=? AND " << YEAR_KEY << "=?"; std::string sql(sqlStream.str()); for (size_t i = 0; i < statements.size(); ++i) { statements[i].SetStatement(sql); Aws::Vector<Aws::DynamoDB::Model::AttributeValue> attributes; attributes.push_back( Aws::DynamoDB::Model::AttributeValue().SetN(ratings[i])); attributes.push_back( Aws::DynamoDB::Model::AttributeValue().SetS(titles[i])); attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetN(years[i])); statements[i].SetParameters(attributes); } Aws::DynamoDB::Model::BatchExecuteStatementRequest request; request.SetStatements(statements); Aws::DynamoDB::Model::BatchExecuteStatementOutcome outcome = dynamoClient.BatchExecuteStatement( request); if (!outcome.IsSuccess()) { std::cerr << "Failed to update movie information: " << outcome.GetError().GetMessage() << std::endl; return false; } } std::cout << "Retrieving the updated movie data with a batch \"SELECT\" statement." << std::endl; // 5. Get the updated data for multiple movies using "Select" statements. (BatchExecuteStatement) { Aws::Vector<Aws::DynamoDB::Model::BatchStatementRequest> statements( titles.size()); std::stringstream sqlStream; sqlStream << "SELECT * FROM \"" << MOVIE_TABLE_NAME << "\" WHERE " << TITLE_KEY << "=? and " << YEAR_KEY << "=?"; std::string sql(sqlStream.str()); for (size_t i = 0; i < statements.size(); ++i) { statements[i].SetStatement(sql); Aws::Vector<Aws::DynamoDB::Model::AttributeValue> attributes; attributes.push_back( Aws::DynamoDB::Model::AttributeValue().SetS(titles[i])); attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetN(years[i])); statements[i].SetParameters(attributes); } Aws::DynamoDB::Model::BatchExecuteStatementRequest request; request.SetStatements(statements); Aws::DynamoDB::Model::BatchExecuteStatementOutcome outcome = dynamoClient.BatchExecuteStatement( request); if (outcome.IsSuccess()) { const Aws::DynamoDB::Model::BatchExecuteStatementResult &result = outcome.GetResult(); const Aws::Vector<Aws::DynamoDB::Model::BatchStatementResponse> &responses = result.GetResponses(); for (const Aws::DynamoDB::Model::BatchStatementResponse &response: responses) { const Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue> &item = response.GetItem(); printMovieInfo(item); } } else { std::cerr << "Failed to retrieve the movies information: " << outcome.GetError().GetMessage() << std::endl; return false; } } std::cout << "Deleting the movie data with a batch \"DELETE\" statement." << std::endl; // 6. Delete multiple movies using "Delete" statements. (BatchExecuteStatement) { Aws::Vector<Aws::DynamoDB::Model::BatchStatementRequest> statements( titles.size()); std::stringstream sqlStream; sqlStream << "DELETE FROM \"" << MOVIE_TABLE_NAME << "\" WHERE " << TITLE_KEY << "=? and " << YEAR_KEY << "=?"; std::string sql(sqlStream.str()); for (size_t i = 0; i < statements.size(); ++i) { statements[i].SetStatement(sql); Aws::Vector<Aws::DynamoDB::Model::AttributeValue> attributes; attributes.push_back( Aws::DynamoDB::Model::AttributeValue().SetS(titles[i])); attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetN(years[i])); statements[i].SetParameters(attributes); } Aws::DynamoDB::Model::BatchExecuteStatementRequest request; request.SetStatements(statements); Aws::DynamoDB::Model::BatchExecuteStatementOutcome outcome = dynamoClient.BatchExecuteStatement( request); if (!outcome.IsSuccess()) { std::cerr << "Failed to delete the movies: " << outcome.GetError().GetMessage() << std::endl; return false; } } return true; } //! Create a DynamoDB table to be used in sample code scenarios. /*! \sa createMoviesDynamoDBTable() \param clientConfiguration: AWS client configuration. \return bool: Function succeeded. */ bool AwsDoc::DynamoDB::createMoviesDynamoDBTable( const Aws::Client::ClientConfiguration &clientConfiguration) { Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration); bool movieTableAlreadyExisted = false; { Aws::DynamoDB::Model::CreateTableRequest request; Aws::DynamoDB::Model::AttributeDefinition yearAttributeDefinition; yearAttributeDefinition.SetAttributeName(YEAR_KEY); yearAttributeDefinition.SetAttributeType( Aws::DynamoDB::Model::ScalarAttributeType::N); request.AddAttributeDefinitions(yearAttributeDefinition); Aws::DynamoDB::Model::AttributeDefinition titleAttributeDefinition; yearAttributeDefinition.SetAttributeName(TITLE_KEY); yearAttributeDefinition.SetAttributeType( Aws::DynamoDB::Model::ScalarAttributeType::S); request.AddAttributeDefinitions(yearAttributeDefinition); Aws::DynamoDB::Model::KeySchemaElement yearKeySchema; yearKeySchema.WithAttributeName(YEAR_KEY).WithKeyType( Aws::DynamoDB::Model::KeyType::HASH); request.AddKeySchema(yearKeySchema); Aws::DynamoDB::Model::KeySchemaElement titleKeySchema; yearKeySchema.WithAttributeName(TITLE_KEY).WithKeyType( Aws::DynamoDB::Model::KeyType::RANGE); request.AddKeySchema(yearKeySchema); Aws::DynamoDB::Model::ProvisionedThroughput throughput; throughput.WithReadCapacityUnits( PROVISIONED_THROUGHPUT_UNITS).WithWriteCapacityUnits( PROVISIONED_THROUGHPUT_UNITS); request.SetProvisionedThroughput(throughput); request.SetTableName(MOVIE_TABLE_NAME); std::cout << "Creating table '" << MOVIE_TABLE_NAME << "'..." << std::endl; const Aws::DynamoDB::Model::CreateTableOutcome &result = dynamoClient.CreateTable( request); if (!result.IsSuccess()) { if (result.GetError().GetErrorType() == Aws::DynamoDB::DynamoDBErrors::RESOURCE_IN_USE) { std::cout << "Table already exists." << std::endl; movieTableAlreadyExisted = true; } else { std::cerr << "Failed to create table: " << result.GetError().GetMessage(); return false; } } } // Wait for table to become active. if (!movieTableAlreadyExisted) { std::cout << "Waiting for table '" << MOVIE_TABLE_NAME << "' to become active...." << std::endl; if (!AwsDoc::DynamoDB::waitTableActive(MOVIE_TABLE_NAME, clientConfiguration)) { return false; } std::cout << "Table '" << MOVIE_TABLE_NAME << "' created and active." << std::endl; } return true; } //! Delete the DynamoDB table used for sample code scenarios. /*! \sa deleteMoviesDynamoDBTable() \param clientConfiguration: AWS client configuration. \return bool: Function succeeded. */ bool AwsDoc::DynamoDB::deleteMoviesDynamoDBTable( const Aws::Client::ClientConfiguration &clientConfiguration) { Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration); Aws::DynamoDB::Model::DeleteTableRequest request; request.SetTableName(MOVIE_TABLE_NAME); const Aws::DynamoDB::Model::DeleteTableOutcome &result = dynamoClient.DeleteTable( request); if (result.IsSuccess()) { std::cout << "Your table \"" << result.GetResult().GetTableDescription().GetTableName() << " was deleted.\n"; } else { std::cerr << "Failed to delete table: " << result.GetError().GetMessage() << std::endl; } return result.IsSuccess(); } //! Query a newly created DynamoDB table until it is active. /*! \sa waitTableActive() \param waitTableActive: The DynamoDB table's name. \param dynamoClient: A DynamoDB client. \return bool: Function succeeded. */ bool AwsDoc::DynamoDB::waitTableActive(const Aws::String &tableName, const Aws::DynamoDB::DynamoDBClient &dynamoClient) { // Repeatedly call DescribeTable until table is ACTIVE. const int MAX_QUERIES = 20; Aws::DynamoDB::Model::DescribeTableRequest request; request.SetTableName(tableName); int count = 0; while (count < MAX_QUERIES) { const Aws::DynamoDB::Model::DescribeTableOutcome &result = dynamoClient.DescribeTable( request); if (result.IsSuccess()) { Aws::DynamoDB::Model::TableStatus status = result.GetResult().GetTable().GetTableStatus(); if (Aws::DynamoDB::Model::TableStatus::ACTIVE != status) { std::this_thread::sleep_for(std::chrono::seconds(1)); } else { return true; } } else { std::cerr << "Error DynamoDB::waitTableActive " << result.GetError().GetMessage() << std::endl; return false; } count++; } return false; }
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Para API obter detalhes, consulte BatchExecuteStatementem AWS SDK for C++ APIReferência.
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O exemplo de código a seguir mostra como:
Obtenha um item executando uma SELECT declaração.
Adicione um item executando uma INSERT declaração.
Atualize um item executando uma UPDATE declaração.
Exclua um item executando uma DELETE declaração.
- SDKpara C++
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nota
Tem mais sobre GitHub. Encontre o exemplo completo e saiba como configurar e executar no Repositório de exemplos de código da AWS
. // 1. Create a table. (CreateTable) if (AwsDoc::DynamoDB::createMoviesDynamoDBTable(clientConfig)) { AwsDoc::DynamoDB::partiqlExecuteScenario(clientConfig); // 7. Delete the table. (DeleteTable) AwsDoc::DynamoDB::deleteMoviesDynamoDBTable(clientConfig); } //! Scenario to modify and query a DynamoDB table using single PartiQL statements. /*! \sa partiqlExecuteScenario() \param clientConfiguration: AWS client configuration. \return bool: Function succeeded. */ bool AwsDoc::DynamoDB::partiqlExecuteScenario( const Aws::Client::ClientConfiguration &clientConfiguration) { Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration); // 2. Add a new movie using an "Insert" statement. (ExecuteStatement) Aws::String title; float rating; int year; Aws::String plot; { title = askQuestion( "Enter the title of a movie you want to add to the table: "); year = askQuestionForInt("What year was it released? "); rating = askQuestionForFloatRange("On a scale of 1 - 10, how do you rate it? ", 1, 10); plot = askQuestion("Summarize the plot for me: "); Aws::DynamoDB::Model::ExecuteStatementRequest request; std::stringstream sqlStream; sqlStream << "INSERT INTO \"" << MOVIE_TABLE_NAME << "\" VALUE {'" << TITLE_KEY << "': ?, '" << YEAR_KEY << "': ?, '" << INFO_KEY << "': ?}"; request.SetStatement(sqlStream.str()); // Create the parameter attributes. Aws::Vector<Aws::DynamoDB::Model::AttributeValue> attributes; attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetS(title)); attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetN(year)); Aws::DynamoDB::Model::AttributeValue infoMapAttribute; std::shared_ptr<Aws::DynamoDB::Model::AttributeValue> ratingAttribute = Aws::MakeShared<Aws::DynamoDB::Model::AttributeValue>( ALLOCATION_TAG.c_str()); ratingAttribute->SetN(rating); infoMapAttribute.AddMEntry(RATING_KEY, ratingAttribute); std::shared_ptr<Aws::DynamoDB::Model::AttributeValue> plotAttribute = Aws::MakeShared<Aws::DynamoDB::Model::AttributeValue>( ALLOCATION_TAG.c_str()); plotAttribute->SetS(plot); infoMapAttribute.AddMEntry(PLOT_KEY, plotAttribute); attributes.push_back(infoMapAttribute); request.SetParameters(attributes); Aws::DynamoDB::Model::ExecuteStatementOutcome outcome = dynamoClient.ExecuteStatement( request); if (!outcome.IsSuccess()) { std::cerr << "Failed to add a movie: " << outcome.GetError().GetMessage() << std::endl; return false; } } std::cout << "\nAdded '" << title << "' to '" << MOVIE_TABLE_NAME << "'." << std::endl; // 3. Get the data for the movie using a "Select" statement. (ExecuteStatement) { Aws::DynamoDB::Model::ExecuteStatementRequest request; std::stringstream sqlStream; sqlStream << "SELECT * FROM \"" << MOVIE_TABLE_NAME << "\" WHERE " << TITLE_KEY << "=? and " << YEAR_KEY << "=?"; request.SetStatement(sqlStream.str()); Aws::Vector<Aws::DynamoDB::Model::AttributeValue> attributes; attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetS(title)); attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetN(year)); request.SetParameters(attributes); Aws::DynamoDB::Model::ExecuteStatementOutcome outcome = dynamoClient.ExecuteStatement( request); if (!outcome.IsSuccess()) { std::cerr << "Failed to retrieve movie information: " << outcome.GetError().GetMessage() << std::endl; return false; } else { // Print the retrieved movie information. const Aws::DynamoDB::Model::ExecuteStatementResult &result = outcome.GetResult(); const Aws::Vector<Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue>> &items = result.GetItems(); if (items.size() == 1) { printMovieInfo(items[0]); } else { std::cerr << "Error: " << items.size() << " movies were retrieved. " << " There should be only one movie." << std::endl; } } } // 4. Update the data for the movie using an "Update" statement. (ExecuteStatement) { rating = askQuestionForFloatRange( Aws::String("\nLet's update your movie.\nYou rated it ") + std::to_string(rating) + ", what new rating would you give it? ", 1, 10); Aws::DynamoDB::Model::ExecuteStatementRequest request; std::stringstream sqlStream; sqlStream << "UPDATE \"" << MOVIE_TABLE_NAME << "\" SET " << INFO_KEY << "." << RATING_KEY << "=? WHERE " << TITLE_KEY << "=? AND " << YEAR_KEY << "=?"; request.SetStatement(sqlStream.str()); Aws::Vector<Aws::DynamoDB::Model::AttributeValue> attributes; attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetN(rating)); attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetS(title)); attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetN(year)); request.SetParameters(attributes); Aws::DynamoDB::Model::ExecuteStatementOutcome outcome = dynamoClient.ExecuteStatement( request); if (!outcome.IsSuccess()) { std::cerr << "Failed to update a movie: " << outcome.GetError().GetMessage(); return false; } } std::cout << "\nUpdated '" << title << "' with new attributes:" << std::endl; // 5. Get the updated data for the movie using a "Select" statement. (ExecuteStatement) { Aws::DynamoDB::Model::ExecuteStatementRequest request; std::stringstream sqlStream; sqlStream << "SELECT * FROM \"" << MOVIE_TABLE_NAME << "\" WHERE " << TITLE_KEY << "=? and " << YEAR_KEY << "=?"; request.SetStatement(sqlStream.str()); Aws::Vector<Aws::DynamoDB::Model::AttributeValue> attributes; attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetS(title)); attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetN(year)); request.SetParameters(attributes); Aws::DynamoDB::Model::ExecuteStatementOutcome outcome = dynamoClient.ExecuteStatement( request); if (!outcome.IsSuccess()) { std::cerr << "Failed to retrieve the movie information: " << outcome.GetError().GetMessage() << std::endl; return false; } else { const Aws::DynamoDB::Model::ExecuteStatementResult &result = outcome.GetResult(); const Aws::Vector<Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue>> &items = result.GetItems(); if (items.size() == 1) { printMovieInfo(items[0]); } else { std::cerr << "Error: " << items.size() << " movies were retrieved. " << " There should be only one movie." << std::endl; } } } std::cout << "Deleting the movie" << std::endl; // 6. Delete the movie using a "Delete" statement. (ExecuteStatement) { Aws::DynamoDB::Model::ExecuteStatementRequest request; std::stringstream sqlStream; sqlStream << "DELETE FROM \"" << MOVIE_TABLE_NAME << "\" WHERE " << TITLE_KEY << "=? and " << YEAR_KEY << "=?"; request.SetStatement(sqlStream.str()); Aws::Vector<Aws::DynamoDB::Model::AttributeValue> attributes; attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetS(title)); attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetN(year)); request.SetParameters(attributes); Aws::DynamoDB::Model::ExecuteStatementOutcome outcome = dynamoClient.ExecuteStatement( request); if (!outcome.IsSuccess()) { std::cerr << "Failed to delete the movie: " << outcome.GetError().GetMessage() << std::endl; return false; } } std::cout << "Movie successfully deleted." << std::endl; return true; } //! Create a DynamoDB table to be used in sample code scenarios. /*! \sa createMoviesDynamoDBTable() \param clientConfiguration: AWS client configuration. \return bool: Function succeeded. */ bool AwsDoc::DynamoDB::createMoviesDynamoDBTable( const Aws::Client::ClientConfiguration &clientConfiguration) { Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration); bool movieTableAlreadyExisted = false; { Aws::DynamoDB::Model::CreateTableRequest request; Aws::DynamoDB::Model::AttributeDefinition yearAttributeDefinition; yearAttributeDefinition.SetAttributeName(YEAR_KEY); yearAttributeDefinition.SetAttributeType( Aws::DynamoDB::Model::ScalarAttributeType::N); request.AddAttributeDefinitions(yearAttributeDefinition); Aws::DynamoDB::Model::AttributeDefinition titleAttributeDefinition; yearAttributeDefinition.SetAttributeName(TITLE_KEY); yearAttributeDefinition.SetAttributeType( Aws::DynamoDB::Model::ScalarAttributeType::S); request.AddAttributeDefinitions(yearAttributeDefinition); Aws::DynamoDB::Model::KeySchemaElement yearKeySchema; yearKeySchema.WithAttributeName(YEAR_KEY).WithKeyType( Aws::DynamoDB::Model::KeyType::HASH); request.AddKeySchema(yearKeySchema); Aws::DynamoDB::Model::KeySchemaElement titleKeySchema; yearKeySchema.WithAttributeName(TITLE_KEY).WithKeyType( Aws::DynamoDB::Model::KeyType::RANGE); request.AddKeySchema(yearKeySchema); Aws::DynamoDB::Model::ProvisionedThroughput throughput; throughput.WithReadCapacityUnits( PROVISIONED_THROUGHPUT_UNITS).WithWriteCapacityUnits( PROVISIONED_THROUGHPUT_UNITS); request.SetProvisionedThroughput(throughput); request.SetTableName(MOVIE_TABLE_NAME); std::cout << "Creating table '" << MOVIE_TABLE_NAME << "'..." << std::endl; const Aws::DynamoDB::Model::CreateTableOutcome &result = dynamoClient.CreateTable( request); if (!result.IsSuccess()) { if (result.GetError().GetErrorType() == Aws::DynamoDB::DynamoDBErrors::RESOURCE_IN_USE) { std::cout << "Table already exists." << std::endl; movieTableAlreadyExisted = true; } else { std::cerr << "Failed to create table: " << result.GetError().GetMessage(); return false; } } } // Wait for table to become active. if (!movieTableAlreadyExisted) { std::cout << "Waiting for table '" << MOVIE_TABLE_NAME << "' to become active...." << std::endl; if (!AwsDoc::DynamoDB::waitTableActive(MOVIE_TABLE_NAME, clientConfiguration)) { return false; } std::cout << "Table '" << MOVIE_TABLE_NAME << "' created and active." << std::endl; } return true; } //! Delete the DynamoDB table used for sample code scenarios. /*! \sa deleteMoviesDynamoDBTable() \param clientConfiguration: AWS client configuration. \return bool: Function succeeded. */ bool AwsDoc::DynamoDB::deleteMoviesDynamoDBTable( const Aws::Client::ClientConfiguration &clientConfiguration) { Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration); Aws::DynamoDB::Model::DeleteTableRequest request; request.SetTableName(MOVIE_TABLE_NAME); const Aws::DynamoDB::Model::DeleteTableOutcome &result = dynamoClient.DeleteTable( request); if (result.IsSuccess()) { std::cout << "Your table \"" << result.GetResult().GetTableDescription().GetTableName() << " was deleted.\n"; } else { std::cerr << "Failed to delete table: " << result.GetError().GetMessage() << std::endl; } return result.IsSuccess(); } //! Query a newly created DynamoDB table until it is active. /*! \sa waitTableActive() \param waitTableActive: The DynamoDB table's name. \param dynamoClient: A DynamoDB client. \return bool: Function succeeded. */ bool AwsDoc::DynamoDB::waitTableActive(const Aws::String &tableName, const Aws::DynamoDB::DynamoDBClient &dynamoClient) { // Repeatedly call DescribeTable until table is ACTIVE. const int MAX_QUERIES = 20; Aws::DynamoDB::Model::DescribeTableRequest request; request.SetTableName(tableName); int count = 0; while (count < MAX_QUERIES) { const Aws::DynamoDB::Model::DescribeTableOutcome &result = dynamoClient.DescribeTable( request); if (result.IsSuccess()) { Aws::DynamoDB::Model::TableStatus status = result.GetResult().GetTable().GetTableStatus(); if (Aws::DynamoDB::Model::TableStatus::ACTIVE != status) { std::this_thread::sleep_for(std::chrono::seconds(1)); } else { return true; } } else { std::cerr << "Error DynamoDB::waitTableActive " << result.GetError().GetMessage() << std::endl; return false; } count++; } return false; }
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Para API obter detalhes, consulte ExecuteStatementem AWS SDK for C++ APIReferência.
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