Contoh DynamoDB menggunakan untuk Ruby SDK - AWS SDKContoh Kode

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Contoh DynamoDB menggunakan untuk Ruby SDK

Contoh kode berikut menunjukkan cara melakukan tindakan dan mengimplementasikan skenario umum dengan menggunakan AWS SDK for Ruby with DynamoDB.

Dasar-dasar adalah contoh kode yang menunjukkan kepada Anda bagaimana melakukan operasi penting dalam suatu layanan.

Tindakan adalah kutipan kode dari program yang lebih besar dan harus dijalankan dalam konteks. Sementara tindakan menunjukkan cara memanggil fungsi layanan individual, Anda dapat melihat tindakan dalam konteks dalam skenario terkait.

Skenario adalah contoh kode yang menunjukkan kepada Anda bagaimana menyelesaikan tugas tertentu dengan memanggil beberapa fungsi dalam layanan atau dikombinasikan dengan yang lain Layanan AWS.

Setiap contoh menyertakan tautan ke kode sumber lengkap, di mana Anda dapat menemukan instruksi tentang cara mengatur dan menjalankan kode dalam konteks.

Memulai

Contoh kode berikut ini menunjukkan cara untuk mulai menggunakan DynamoDB.

SDKuntuk Ruby
catatan

Ada lebih banyak tentang GitHub. Temukan contoh lengkapnya dan pelajari cara pengaturan dan menjalankannya di Repositori Contoh Kode AWS.

require 'aws-sdk-dynamodb' require 'logger' # DynamoDBManager is a class responsible for managing DynamoDB operations # such as listing all tables in the current AWS account. class DynamoDBManager def initialize(client) @client = client @logger = Logger.new($stdout) end # Lists and prints all DynamoDB tables in the current AWS account. def list_tables @logger.info('Here are the DynamoDB tables in your account:') paginator = @client.list_tables(limit: 10) table_names = [] paginator.each_page do |page| page.table_names.each do |table_name| @logger.info("- #{table_name}") table_names << table_name end end if table_names.empty? @logger.info("You don't have any DynamoDB tables in your account.") else @logger.info("\nFound #{table_names.length} tables.") end end end if $PROGRAM_NAME == __FILE__ dynamodb_client = Aws::DynamoDB::Client.new manager = DynamoDBManager.new(dynamodb_client) manager.list_tables end
  • Untuk API detailnya, lihat ListTablesdi AWS SDK for Ruby APIReferensi.

Hal-hal mendasar

Contoh kode berikut ini menunjukkan cara:

  • Buat tabel yang dapat menyimpan data film.

  • Masukkan, dapatkan, dan perbarui satu film dalam tabel tersebut.

  • Tulis data film ke tabel dari JSON file sampel.

  • Kueri untuk film yang dirilis pada tahun tertentu.

  • Pindai film yang dirilis dalam suatu rentang tahun.

  • Hapus film dari tabel, lalu hapus tabel tersebut.

SDKuntuk Ruby
catatan

Ada lebih banyak tentang GitHub. Temukan contoh lengkapnya dan pelajari cara pengaturan dan menjalankannya di Repositori Contoh Kode AWS.

Buat kelas yang merangkum tabel DynamoDB.

# Creates an Amazon DynamoDB table that can be used to store movie data. # The table uses the release year of the movie as the partition key and the # title as the sort key. # # @param table_name [String] The name of the table to create. # @return [Aws::DynamoDB::Table] The newly created table. def create_table(table_name) @table = @dynamo_resource.create_table( table_name: table_name, key_schema: [ { attribute_name: 'year', key_type: 'HASH' }, # Partition key { attribute_name: 'title', key_type: 'RANGE' } # Sort key ], attribute_definitions: [ { attribute_name: 'year', attribute_type: 'N' }, { attribute_name: 'title', attribute_type: 'S' } ], provisioned_throughput: { read_capacity_units: 10, write_capacity_units: 10 } ) @dynamo_resource.client.wait_until(:table_exists, table_name: table_name) @table rescue Aws::DynamoDB::Errors::ServiceError => e @logger.error("Failed create table #{table_name}:\n#{e.code}: #{e.message}") raise end

Buat fungsi pembantu untuk mengunduh dan mengekstrak JSON file sampel.

# Gets sample movie data, either from a local file or by first downloading it from # the Amazon DynamoDB Developer Guide. # # @param movie_file_name [String] The local file name where the movie data is stored in JSON format. # @return [Hash] The movie data as a Hash. def fetch_movie_data(movie_file_name) if !File.file?(movie_file_name) @logger.debug("Downloading #{movie_file_name}...") movie_content = URI.open( 'https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/samples/moviedata.zip' ) movie_json = '' Zip::File.open_buffer(movie_content) do |zip| zip.each do |entry| movie_json = entry.get_input_stream.read end end else movie_json = File.read(movie_file_name) end movie_data = JSON.parse(movie_json) # The sample file lists over 4000 movies. This returns only the first 250. movie_data.slice(0, 250) rescue StandardError => e puts("Failure downloading movie data:\n#{e}") raise end

Jalankan skenario interaktif untuk membuat tabel dan melakukan tindakan pada tabel tersebut.

table_name = "doc-example-table-movies-#{rand(10**4)}" scaffold = Scaffold.new(table_name) dynamodb_wrapper = DynamoDBBasics.new(table_name) new_step(1, 'Create a new DynamoDB table if none already exists.') unless scaffold.exists?(table_name) puts("\nNo such table: #{table_name}. Creating it...") scaffold.create_table(table_name) print "Done!\n".green end new_step(2, 'Add a new record to the DynamoDB table.') my_movie = {} my_movie[:title] = CLI::UI::Prompt.ask('Enter the title of a movie to add to the table. E.g. The Matrix') my_movie[:year] = CLI::UI::Prompt.ask('What year was it released? E.g. 1989').to_i my_movie[:rating] = CLI::UI::Prompt.ask('On a scale of 1 - 10, how do you rate it? E.g. 7').to_i my_movie[:plot] = CLI::UI::Prompt.ask('Enter a brief summary of the plot. E.g. A man awakens to a new reality.') dynamodb_wrapper.add_item(my_movie) puts("\nNew record added:") puts JSON.pretty_generate(my_movie).green print "Done!\n".green new_step(3, 'Update a record in the DynamoDB table.') my_movie[:rating] = CLI::UI::Prompt.ask("Let's update the movie you added with a new rating, e.g. 3:").to_i response = dynamodb_wrapper.update_item(my_movie) puts("Updated '#{my_movie[:title]}' with new attributes:") puts JSON.pretty_generate(response).green print "Done!\n".green new_step(4, 'Get a record from the DynamoDB table.') puts("Searching for #{my_movie[:title]} (#{my_movie[:year]})...") response = dynamodb_wrapper.get_item(my_movie[:title], my_movie[:year]) puts JSON.pretty_generate(response).green print "Done!\n".green new_step(5, 'Write a batch of items into the DynamoDB table.') download_file = 'moviedata.json' puts("Downloading movie database to #{download_file}...") movie_data = scaffold.fetch_movie_data(download_file) puts("Writing movie data from #{download_file} into your table...") scaffold.write_batch(movie_data) puts("Records added: #{movie_data.length}.") print "Done!\n".green new_step(5, 'Query for a batch of items by key.') loop do release_year = CLI::UI::Prompt.ask('Enter a year between 1972 and 2018, e.g. 1999:').to_i results = dynamodb_wrapper.query_items(release_year) if results.any? puts("There were #{results.length} movies released in #{release_year}:") results.each do |movie| print "\t #{movie['title']}".green end break else continue = CLI::UI::Prompt.ask("Found no movies released in #{release_year}! Try another year? (y/n)") break unless continue.eql?('y') end end print "\nDone!\n".green new_step(6, 'Scan for a batch of items using a filter expression.') years = {} years[:start] = CLI::UI::Prompt.ask('Enter a starting year between 1972 and 2018:') years[:end] = CLI::UI::Prompt.ask('Enter an ending year between 1972 and 2018:') releases = dynamodb_wrapper.scan_items(years) if !releases.empty? puts("Found #{releases.length} movies.") count = Question.ask( 'How many do you want to see? ', method(:is_int), in_range(1, releases.length) ) puts("Here are your #{count} movies:") releases.take(count).each do |release| puts("\t#{release['title']}") end else puts("I don't know about any movies released between #{years[:start]} "\ "and #{years[:end]}.") end print "\nDone!\n".green new_step(7, 'Delete an item from the DynamoDB table.') answer = CLI::UI::Prompt.ask("Do you want to remove '#{my_movie[:title]}'? (y/n) ") if answer.eql?('y') dynamodb_wrapper.delete_item(my_movie[:title], my_movie[:year]) puts("Removed '#{my_movie[:title]}' from the table.") print "\nDone!\n".green end new_step(8, 'Delete the DynamoDB table.') answer = CLI::UI::Prompt.ask('Delete the table? (y/n)') if answer.eql?('y') scaffold.delete_table puts("Deleted #{table_name}.") else puts("Don't forget to delete the table when you're done!") end print "\nThanks for watching!\n".green rescue Aws::Errors::ServiceError puts('Something went wrong with the demo.') rescue Errno::ENOENT true end

Tindakan

Contoh kode berikut menunjukkan cara menggunakanBatchExecuteStatement.

SDKuntuk Ruby
catatan

Ada lebih banyak tentang GitHub. Temukan contoh lengkapnya dan pelajari cara pengaturan dan menjalankannya di Repositori Contoh Kode AWS.

Baca batch item menggunakan PartiQL.

class DynamoDBPartiQLBatch attr_reader :dynamo_resource, :table def initialize(table_name) client = Aws::DynamoDB::Client.new(region: 'us-east-1') @dynamodb = Aws::DynamoDB::Resource.new(client: client) @table = @dynamodb.table(table_name) end # Selects a batch of items from a table using PartiQL # # @param batch_titles [Array] Collection of movie titles # @return [Aws::DynamoDB::Types::BatchExecuteStatementOutput] def batch_execute_select(batch_titles) request_items = batch_titles.map do |title, year| { statement: "SELECT * FROM \"#{@table.name}\" WHERE title=? and year=?", parameters: [title, year] } end @dynamodb.client.batch_execute_statement({ statements: request_items }) end

Hapus batch item menggunakan PartiQL.

class DynamoDBPartiQLBatch attr_reader :dynamo_resource, :table def initialize(table_name) client = Aws::DynamoDB::Client.new(region: 'us-east-1') @dynamodb = Aws::DynamoDB::Resource.new(client: client) @table = @dynamodb.table(table_name) end # Deletes a batch of items from a table using PartiQL # # @param batch_titles [Array] Collection of movie titles # @return [Aws::DynamoDB::Types::BatchExecuteStatementOutput] def batch_execute_write(batch_titles) request_items = batch_titles.map do |title, year| { statement: "DELETE FROM \"#{@table.name}\" WHERE title=? and year=?", parameters: [title, year] } end @dynamodb.client.batch_execute_statement({ statements: request_items }) end

Contoh kode berikut menunjukkan cara menggunakanBatchWriteItem.

SDKuntuk Ruby
catatan

Ada lebih banyak tentang GitHub. Temukan contoh lengkapnya dan pelajari cara pengaturan dan menjalankannya di Repositori Contoh Kode AWS.

class DynamoDBBasics attr_reader :dynamo_resource, :table def initialize(table_name) client = Aws::DynamoDB::Client.new(region: 'us-east-1') @dynamo_resource = Aws::DynamoDB::Resource.new(client: client) @table = @dynamo_resource.table(table_name) end # Fills an Amazon DynamoDB table with the specified data. Items are sent in # batches of 25 until all items are written. # # @param movies [Enumerable] The data to put in the table. Each item must contain at least # the keys required by the schema that was specified when the # table was created. def write_batch(movies) index = 0 slice_size = 25 while index < movies.length movie_items = [] movies[index, slice_size].each do |movie| movie_items.append({ put_request: { item: movie } }) end @dynamo_resource.client.batch_write_item({ request_items: { @table.name => movie_items } }) index += slice_size end rescue Aws::DynamoDB::Errors::ServiceError => e puts( "Couldn't load data into table #{@table.name}. Here's why:" ) puts("\t#{e.code}: #{e.message}") raise end
  • Untuk API detailnya, lihat BatchWriteItemdi AWS SDK for Ruby APIReferensi.

Contoh kode berikut menunjukkan cara menggunakanCreateTable.

SDKuntuk Ruby
catatan

Ada lebih banyak tentang GitHub. Temukan contoh lengkapnya dan pelajari cara pengaturan dan menjalankannya di Repositori Contoh Kode AWS.

# Encapsulates an Amazon DynamoDB table of movie data. class Scaffold attr_reader :dynamo_resource, :table_name, :table def initialize(table_name) client = Aws::DynamoDB::Client.new(region: 'us-east-1') @dynamo_resource = Aws::DynamoDB::Resource.new(client: client) @table_name = table_name @table = nil @logger = Logger.new($stdout) @logger.level = Logger::DEBUG end # Creates an Amazon DynamoDB table that can be used to store movie data. # The table uses the release year of the movie as the partition key and the # title as the sort key. # # @param table_name [String] The name of the table to create. # @return [Aws::DynamoDB::Table] The newly created table. def create_table(table_name) @table = @dynamo_resource.create_table( table_name: table_name, key_schema: [ { attribute_name: 'year', key_type: 'HASH' }, # Partition key { attribute_name: 'title', key_type: 'RANGE' } # Sort key ], attribute_definitions: [ { attribute_name: 'year', attribute_type: 'N' }, { attribute_name: 'title', attribute_type: 'S' } ], provisioned_throughput: { read_capacity_units: 10, write_capacity_units: 10 } ) @dynamo_resource.client.wait_until(:table_exists, table_name: table_name) @table rescue Aws::DynamoDB::Errors::ServiceError => e @logger.error("Failed create table #{table_name}:\n#{e.code}: #{e.message}") raise end
  • Untuk API detailnya, lihat CreateTabledi AWS SDK for Ruby APIReferensi.

Contoh kode berikut menunjukkan cara menggunakanDeleteItem.

SDKuntuk Ruby
catatan

Ada lebih banyak tentang GitHub. Temukan contoh lengkapnya dan pelajari cara pengaturan dan menjalankannya di Repositori Contoh Kode AWS.

class DynamoDBBasics attr_reader :dynamo_resource, :table def initialize(table_name) client = Aws::DynamoDB::Client.new(region: 'us-east-1') @dynamo_resource = Aws::DynamoDB::Resource.new(client: client) @table = @dynamo_resource.table(table_name) end # Deletes a movie from the table. # # @param title [String] The title of the movie to delete. # @param year [Integer] The release year of the movie to delete. def delete_item(title, year) @table.delete_item(key: { 'year' => year, 'title' => title }) rescue Aws::DynamoDB::Errors::ServiceError => e puts("Couldn't delete movie #{title}. Here's why:") puts("\t#{e.code}: #{e.message}") raise end
  • Untuk API detailnya, lihat DeleteItemdi AWS SDK for Ruby APIReferensi.

Contoh kode berikut menunjukkan cara menggunakanDeleteTable.

SDKuntuk Ruby
catatan

Ada lebih banyak tentang GitHub. Temukan contoh lengkapnya dan pelajari cara pengaturan dan menjalankannya di Repositori Contoh Kode AWS.

# Encapsulates an Amazon DynamoDB table of movie data. class Scaffold attr_reader :dynamo_resource, :table_name, :table def initialize(table_name) client = Aws::DynamoDB::Client.new(region: 'us-east-1') @dynamo_resource = Aws::DynamoDB::Resource.new(client: client) @table_name = table_name @table = nil @logger = Logger.new($stdout) @logger.level = Logger::DEBUG end # Deletes the table. def delete_table @table.delete @table = nil rescue Aws::DynamoDB::Errors::ServiceError => e puts("Couldn't delete table. Here's why:") puts("\t#{e.code}: #{e.message}") raise end
  • Untuk API detailnya, lihat DeleteTabledi AWS SDK for Ruby APIReferensi.

Contoh kode berikut menunjukkan cara menggunakanDescribeTable.

SDKuntuk Ruby
catatan

Ada lebih banyak tentang GitHub. Temukan contoh lengkapnya dan pelajari cara pengaturan dan menjalankannya di Repositori Contoh Kode AWS.

# Encapsulates an Amazon DynamoDB table of movie data. class Scaffold attr_reader :dynamo_resource, :table_name, :table def initialize(table_name) client = Aws::DynamoDB::Client.new(region: 'us-east-1') @dynamo_resource = Aws::DynamoDB::Resource.new(client: client) @table_name = table_name @table = nil @logger = Logger.new($stdout) @logger.level = Logger::DEBUG end # Determines whether a table exists. As a side effect, stores the table in # a member variable. # # @param table_name [String] The name of the table to check. # @return [Boolean] True when the table exists; otherwise, False. def exists?(table_name) @dynamo_resource.client.describe_table(table_name: table_name) @logger.debug("Table #{table_name} exists") rescue Aws::DynamoDB::Errors::ResourceNotFoundException @logger.debug("Table #{table_name} doesn't exist") false rescue Aws::DynamoDB::Errors::ServiceError => e puts("Couldn't check for existence of #{table_name}:\n") puts("\t#{e.code}: #{e.message}") raise end
  • Untuk API detailnya, lihat DescribeTabledi AWS SDK for Ruby APIReferensi.

Contoh kode berikut menunjukkan cara menggunakanExecuteStatement.

SDKuntuk Ruby
catatan

Ada lebih banyak tentang GitHub. Temukan contoh lengkapnya dan pelajari cara pengaturan dan menjalankannya di Repositori Contoh Kode AWS.

Pilih satu item menggunakan PartiQL.

class DynamoDBPartiQLSingle attr_reader :dynamo_resource, :table def initialize(table_name) client = Aws::DynamoDB::Client.new(region: 'us-east-1') @dynamodb = Aws::DynamoDB::Resource.new(client: client) @table = @dynamodb.table(table_name) end # Gets a single record from a table using PartiQL. # Note: To perform more fine-grained selects, # use the Client.query instance method instead. # # @param title [String] The title of the movie to search. # @return [Aws::DynamoDB::Types::ExecuteStatementOutput] def select_item_by_title(title) request = { statement: "SELECT * FROM \"#{@table.name}\" WHERE title=?", parameters: [title] } @dynamodb.client.execute_statement(request) end

Perbarui satu item menggunakan PartiQL.

class DynamoDBPartiQLSingle attr_reader :dynamo_resource, :table def initialize(table_name) client = Aws::DynamoDB::Client.new(region: 'us-east-1') @dynamodb = Aws::DynamoDB::Resource.new(client: client) @table = @dynamodb.table(table_name) end # Updates a single record from a table using PartiQL. # # @param title [String] The title of the movie to update. # @param year [Integer] The year the movie was released. # @param rating [Float] The new rating to assign the title. # @return [Aws::DynamoDB::Types::ExecuteStatementOutput] def update_rating_by_title(title, year, rating) request = { statement: "UPDATE \"#{@table.name}\" SET info.rating=? WHERE title=? and year=?", parameters: [{ "N": rating }, title, year] } @dynamodb.client.execute_statement(request) end

Tambahkan satu item menggunakan PartiQL.

class DynamoDBPartiQLSingle attr_reader :dynamo_resource, :table def initialize(table_name) client = Aws::DynamoDB::Client.new(region: 'us-east-1') @dynamodb = Aws::DynamoDB::Resource.new(client: client) @table = @dynamodb.table(table_name) end # Adds a single record to a table using PartiQL. # # @param title [String] The title of the movie to update. # @param year [Integer] The year the movie was released. # @param plot [String] The plot of the movie. # @param rating [Float] The new rating to assign the title. # @return [Aws::DynamoDB::Types::ExecuteStatementOutput] def insert_item(title, year, plot, rating) request = { statement: "INSERT INTO \"#{@table.name}\" VALUE {'title': ?, 'year': ?, 'info': ?}", parameters: [title, year, { 'plot': plot, 'rating': rating }] } @dynamodb.client.execute_statement(request) end

Hapus satu item menggunakan PartiQL.

class DynamoDBPartiQLSingle attr_reader :dynamo_resource, :table def initialize(table_name) client = Aws::DynamoDB::Client.new(region: 'us-east-1') @dynamodb = Aws::DynamoDB::Resource.new(client: client) @table = @dynamodb.table(table_name) end # Deletes a single record from a table using PartiQL. # # @param title [String] The title of the movie to update. # @param year [Integer] The year the movie was released. # @return [Aws::DynamoDB::Types::ExecuteStatementOutput] def delete_item_by_title(title, year) request = { statement: "DELETE FROM \"#{@table.name}\" WHERE title=? and year=?", parameters: [title, year] } @dynamodb.client.execute_statement(request) end

Contoh kode berikut menunjukkan cara menggunakanGetItem.

SDKuntuk Ruby
catatan

Ada lebih banyak tentang GitHub. Temukan contoh lengkapnya dan pelajari cara pengaturan dan menjalankannya di Repositori Contoh Kode AWS.

class DynamoDBBasics attr_reader :dynamo_resource, :table def initialize(table_name) client = Aws::DynamoDB::Client.new(region: 'us-east-1') @dynamo_resource = Aws::DynamoDB::Resource.new(client: client) @table = @dynamo_resource.table(table_name) end # Gets movie data from the table for a specific movie. # # @param title [String] The title of the movie. # @param year [Integer] The release year of the movie. # @return [Hash] The data about the requested movie. def get_item(title, year) @table.get_item(key: { 'year' => year, 'title' => title }) rescue Aws::DynamoDB::Errors::ServiceError => e puts("Couldn't get movie #{title} (#{year}) from table #{@table.name}:\n") puts("\t#{e.code}: #{e.message}") raise end
  • Untuk API detailnya, lihat GetItemdi AWS SDK for Ruby APIReferensi.

Contoh kode berikut menunjukkan cara menggunakanListTables.

SDKuntuk Ruby
catatan

Ada lebih banyak tentang GitHub. Temukan contoh lengkapnya dan pelajari cara pengaturan dan menjalankannya di Repositori Contoh Kode AWS.

Tentukan apakah tabel ada.

# Encapsulates an Amazon DynamoDB table of movie data. class Scaffold attr_reader :dynamo_resource, :table_name, :table def initialize(table_name) client = Aws::DynamoDB::Client.new(region: 'us-east-1') @dynamo_resource = Aws::DynamoDB::Resource.new(client: client) @table_name = table_name @table = nil @logger = Logger.new($stdout) @logger.level = Logger::DEBUG end # Determines whether a table exists. As a side effect, stores the table in # a member variable. # # @param table_name [String] The name of the table to check. # @return [Boolean] True when the table exists; otherwise, False. def exists?(table_name) @dynamo_resource.client.describe_table(table_name: table_name) @logger.debug("Table #{table_name} exists") rescue Aws::DynamoDB::Errors::ResourceNotFoundException @logger.debug("Table #{table_name} doesn't exist") false rescue Aws::DynamoDB::Errors::ServiceError => e puts("Couldn't check for existence of #{table_name}:\n") puts("\t#{e.code}: #{e.message}") raise end
  • Untuk API detailnya, lihat ListTablesdi AWS SDK for Ruby APIReferensi.

Contoh kode berikut menunjukkan cara menggunakanPutItem.

SDKuntuk Ruby
catatan

Ada lebih banyak tentang GitHub. Temukan contoh lengkapnya dan pelajari cara pengaturan dan menjalankannya di Repositori Contoh Kode AWS.

class DynamoDBBasics attr_reader :dynamo_resource, :table def initialize(table_name) client = Aws::DynamoDB::Client.new(region: 'us-east-1') @dynamo_resource = Aws::DynamoDB::Resource.new(client: client) @table = @dynamo_resource.table(table_name) end # Adds a movie to the table. # # @param movie [Hash] The title, year, plot, and rating of the movie. def add_item(movie) @table.put_item( item: { 'year' => movie[:year], 'title' => movie[:title], 'info' => { 'plot' => movie[:plot], 'rating' => movie[:rating] } } ) rescue Aws::DynamoDB::Errors::ServiceError => e puts("Couldn't add movie #{title} to table #{@table.name}. Here's why:") puts("\t#{e.code}: #{e.message}") raise end
  • Untuk API detailnya, lihat PutItemdi AWS SDK for Ruby APIReferensi.

Contoh kode berikut menunjukkan cara menggunakanQuery.

SDKuntuk Ruby
catatan

Ada lebih banyak tentang GitHub. Temukan contoh lengkapnya dan pelajari cara pengaturan dan menjalankannya di Repositori Contoh Kode AWS.

class DynamoDBBasics attr_reader :dynamo_resource, :table def initialize(table_name) client = Aws::DynamoDB::Client.new(region: 'us-east-1') @dynamo_resource = Aws::DynamoDB::Resource.new(client: client) @table = @dynamo_resource.table(table_name) end # Queries for movies that were released in the specified year. # # @param year [Integer] The year to query. # @return [Array] The list of movies that were released in the specified year. def query_items(year) response = @table.query( key_condition_expression: '#yr = :year', expression_attribute_names: { '#yr' => 'year' }, expression_attribute_values: { ':year' => year } ) rescue Aws::DynamoDB::Errors::ServiceError => e puts("Couldn't query for movies released in #{year}. Here's why:") puts("\t#{e.code}: #{e.message}") raise else response.items end
  • Untuk API detailnya, lihat Kueri di AWS SDK for Ruby APIReferensi.

Contoh kode berikut menunjukkan cara menggunakanScan.

SDKuntuk Ruby
catatan

Ada lebih banyak tentang GitHub. Temukan contoh lengkapnya dan pelajari cara pengaturan dan menjalankannya di Repositori Contoh Kode AWS.

class DynamoDBBasics attr_reader :dynamo_resource, :table def initialize(table_name) client = Aws::DynamoDB::Client.new(region: 'us-east-1') @dynamo_resource = Aws::DynamoDB::Resource.new(client: client) @table = @dynamo_resource.table(table_name) end # Scans for movies that were released in a range of years. # Uses a projection expression to return a subset of data for each movie. # # @param year_range [Hash] The range of years to retrieve. # @return [Array] The list of movies released in the specified years. def scan_items(year_range) movies = [] scan_hash = { filter_expression: '#yr between :start_yr and :end_yr', projection_expression: '#yr, title, info.rating', expression_attribute_names: { '#yr' => 'year' }, expression_attribute_values: { ':start_yr' => year_range[:start], ':end_yr' => year_range[:end] } } done = false start_key = nil until done scan_hash[:exclusive_start_key] = start_key unless start_key.nil? response = @table.scan(scan_hash) movies.concat(response.items) unless response.items.empty? start_key = response.last_evaluated_key done = start_key.nil? end rescue Aws::DynamoDB::Errors::ServiceError => e puts("Couldn't scan for movies. Here's why:") puts("\t#{e.code}: #{e.message}") raise else movies end
  • Untuk API detailnya, lihat Memindai di AWS SDK for Ruby APIReferensi.

Contoh kode berikut menunjukkan cara menggunakanUpdateItem.

SDKuntuk Ruby
catatan

Ada lebih banyak tentang GitHub. Temukan contoh lengkapnya dan pelajari cara pengaturan dan menjalankannya di Repositori Contoh Kode AWS.

class DynamoDBBasics attr_reader :dynamo_resource, :table def initialize(table_name) client = Aws::DynamoDB::Client.new(region: 'us-east-1') @dynamo_resource = Aws::DynamoDB::Resource.new(client: client) @table = @dynamo_resource.table(table_name) end # Updates rating and plot data for a movie in the table. # # @param movie [Hash] The title, year, plot, rating of the movie. def update_item(movie) response = @table.update_item( key: { 'year' => movie[:year], 'title' => movie[:title] }, update_expression: 'set info.rating=:r', expression_attribute_values: { ':r' => movie[:rating] }, return_values: 'UPDATED_NEW' ) rescue Aws::DynamoDB::Errors::ServiceError => e puts("Couldn't update movie #{movie[:title]} (#{movie[:year]}) in table #{@table.name}\n") puts("\t#{e.code}: #{e.message}") raise else response.attributes end
  • Untuk API detailnya, lihat UpdateItemdi AWS SDK for Ruby APIReferensi.

Skenario

Contoh kode berikut ini menunjukkan cara:

  • Dapatkan sekumpulan item dengan menjalankan beberapa SELECT pernyataan.

  • Tambahkan sekumpulan item dengan menjalankan beberapa INSERT pernyataan.

  • Perbarui sekumpulan item dengan menjalankan beberapa UPDATE pernyataan.

  • Hapus sekumpulan item dengan menjalankan beberapa DELETE pernyataan.

SDKuntuk Ruby
catatan

Ada lebih banyak tentang GitHub. Temukan contoh lengkapnya dan pelajari cara pengaturan dan menjalankannya di Repositori Contoh Kode AWS.

Jalankan skenario yang membuat tabel dan menjalankan batch kueri PartiQL.

table_name = "doc-example-table-movies-partiql-#{rand(10**4)}" scaffold = Scaffold.new(table_name) sdk = DynamoDBPartiQLBatch.new(table_name) new_step(1, 'Create a new DynamoDB table if none already exists.') unless scaffold.exists?(table_name) puts("\nNo such table: #{table_name}. Creating it...") scaffold.create_table(table_name) print "Done!\n".green end new_step(2, 'Populate DynamoDB table with movie data.') download_file = 'moviedata.json' puts("Downloading movie database to #{download_file}...") movie_data = scaffold.fetch_movie_data(download_file) puts("Writing movie data from #{download_file} into your table...") scaffold.write_batch(movie_data) puts("Records added: #{movie_data.length}.") print "Done!\n".green new_step(3, 'Select a batch of items from the movies table.') puts "Let's select some popular movies for side-by-side comparison." response = sdk.batch_execute_select([['Mean Girls', 2004], ['Goodfellas', 1977], ['The Prancing of the Lambs', 2005]]) puts("Items selected: #{response['responses'].length}\n") print "\nDone!\n".green new_step(4, 'Delete a batch of items from the movies table.') sdk.batch_execute_write([['Mean Girls', 2004], ['Goodfellas', 1977], ['The Prancing of the Lambs', 2005]]) print "\nDone!\n".green new_step(5, 'Delete the table.') return unless scaffold.exists?(table_name) scaffold.delete_table end

Contoh kode berikut ini menunjukkan cara:

  • Dapatkan item dengan menjalankan SELECT pernyataan.

  • Tambahkan item dengan menjalankan INSERT pernyataan.

  • Perbarui item dengan menjalankan UPDATE pernyataan.

  • Hapus item dengan menjalankan DELETE pernyataan.

SDKuntuk Ruby
catatan

Ada lebih banyak tentang GitHub. Temukan contoh lengkapnya dan pelajari cara pengaturan dan menjalankannya di Repositori Contoh Kode AWS.

Jalankan skenario yang membuat tabel dan menjalankan kueri PartiQL.

table_name = "doc-example-table-movies-partiql-#{rand(10**8)}" scaffold = Scaffold.new(table_name) sdk = DynamoDBPartiQLSingle.new(table_name) new_step(1, 'Create a new DynamoDB table if none already exists.') unless scaffold.exists?(table_name) puts("\nNo such table: #{table_name}. Creating it...") scaffold.create_table(table_name) print "Done!\n".green end new_step(2, 'Populate DynamoDB table with movie data.') download_file = 'moviedata.json' puts("Downloading movie database to #{download_file}...") movie_data = scaffold.fetch_movie_data(download_file) puts("Writing movie data from #{download_file} into your table...") scaffold.write_batch(movie_data) puts("Records added: #{movie_data.length}.") print "Done!\n".green new_step(3, 'Select a single item from the movies table.') response = sdk.select_item_by_title('Star Wars') puts("Items selected for title 'Star Wars': #{response.items.length}\n") print response.items.first.to_s.yellow print "\n\nDone!\n".green new_step(4, 'Update a single item from the movies table.') puts "Let's correct the rating on The Big Lebowski to 10.0." sdk.update_rating_by_title('The Big Lebowski', 1998, 10.0) print "\nDone!\n".green new_step(5, 'Delete a single item from the movies table.') puts "Let's delete The Silence of the Lambs because it's just too scary." sdk.delete_item_by_title('The Silence of the Lambs', 1991) print "\nDone!\n".green new_step(6, 'Insert a new item into the movies table.') puts "Let's create a less-scary movie called The Prancing of the Lambs." sdk.insert_item('The Prancing of the Lambs', 2005, 'A movie about happy livestock.', 5.0) print "\nDone!\n".green new_step(7, 'Delete the table.') return unless scaffold.exists?(table_name) scaffold.delete_table end

Contoh nirserver

Contoh kode berikut menunjukkan bagaimana menerapkan fungsi Lambda yang menerima peristiwa yang dipicu oleh menerima catatan dari aliran DynamoDB. Fungsi mengambil payload DynamoDB dan mencatat isi catatan.

SDKuntuk Ruby
catatan

Ada lebih banyak tentang GitHub. Temukan contoh lengkapnya dan pelajari cara mengatur dan menjalankannya di repositori contoh Nirserver.

Mengkonsumsi acara DynamoDB dengan Lambda menggunakan Ruby.

def lambda_handler(event:, context:) return 'received empty event' if event['Records'].empty? event['Records'].each do |record| log_dynamodb_record(record) end "Records processed: #{event['Records'].length}" end def log_dynamodb_record(record) puts record['eventID'] puts record['eventName'] puts "DynamoDB Record: #{JSON.generate(record['dynamodb'])}" end

Contoh kode berikut menunjukkan cara mengimplementasikan respons batch sebagian untuk fungsi Lambda yang menerima peristiwa dari aliran DynamoDB. Fungsi melaporkan kegagalan item batch dalam respons, memberi sinyal ke Lambda untuk mencoba lagi pesan tersebut nanti.

SDKuntuk Ruby
catatan

Ada lebih banyak tentang GitHub. Temukan contoh lengkapnya dan pelajari cara mengatur dan menjalankannya di repositori contoh Nirserver.

Melaporkan kegagalan item batch DynamoDB dengan Lambda menggunakan Ruby.

def lambda_handler(event:, context:) records = event["Records"] cur_record_sequence_number = "" records.each do |record| begin # Process your record cur_record_sequence_number = record["dynamodb"]["SequenceNumber"] rescue StandardError => e # Return failed record's sequence number return {"batchItemFailures" => [{"itemIdentifier" => cur_record_sequence_number}]} end end {"batchItemFailures" => []} end