Get information about a DynamoDB table - Amazon DynamoDB
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Get information about a DynamoDB table

The following code examples show how to get information about a DynamoDB table.

.NET
Amazon SDK for .NET
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the Amazon Code Examples Repository.

public static async Task<bool> GetTableInformation(AmazonDynamoDBClient client) { Console.WriteLine("\n*** Retrieving table information ***"); var request = new DescribeTableRequest { TableName = _tableName }; var response = await client.DescribeTableAsync(request); TableDescription description = response.Table; Console.WriteLine("Name: {0}", description.TableName); Console.WriteLine("# of items: {0}", description.ItemCount); Console.WriteLine("Provision Throughput (reads/sec): {0}", description.ProvisionedThroughput.ReadCapacityUnits); Console.WriteLine("Provision Throughput (writes/sec): {0}", description.ProvisionedThroughput.WriteCapacityUnits); return true; }
  • For API details, see DescribeTable in Amazon SDK for .NET API Reference.

C++
SDK for C++
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the Amazon Code Examples Repository.

//! 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(); }
  • For API details, see DescribeTable in Amazon SDK for C++ API Reference.

Go
SDK for Go V2
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the Amazon Code Examples Repository.

// TableBasics encapsulates the Amazon DynamoDB service actions used in the examples. // It contains a DynamoDB service client that is used to act on the specified table. type TableBasics struct { DynamoDbClient *dynamodb.Client TableName string } // TableExists determines whether a DynamoDB table exists. func (basics TableBasics) TableExists() (bool, error) { exists := true _, err := basics.DynamoDbClient.DescribeTable( context.TODO(), &dynamodb.DescribeTableInput{TableName: aws.String(basics.TableName)}, ) if err != nil { var notFoundEx *types.ResourceNotFoundException if errors.As(err, &notFoundEx) { log.Printf("Table %v does not exist.\n", basics.TableName) err = nil } else { log.Printf("Couldn't determine existence of table %v. Here's why: %v\n", basics.TableName, err) } exists = false } return exists, err }
  • For API details, see DescribeTable in Amazon SDK for Go API Reference.

Java
SDK for Java 2.x
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the Amazon Code Examples Repository.

public static void describeDymamoDBTable(DynamoDbClient ddb,String tableName ) { DescribeTableRequest request = DescribeTableRequest.builder() .tableName(tableName) .build(); try { TableDescription tableInfo = ddb.describeTable(request).table(); if (tableInfo != null) { System.out.format("Table name : %s\n", tableInfo.tableName()); System.out.format("Table ARN : %s\n", tableInfo.tableArn()); System.out.format("Status : %s\n", tableInfo.tableStatus()); System.out.format("Item count : %d\n", tableInfo.itemCount().longValue()); System.out.format("Size (bytes): %d\n", tableInfo.tableSizeBytes().longValue()); ProvisionedThroughputDescription throughputInfo = tableInfo.provisionedThroughput(); System.out.println("Throughput"); System.out.format(" Read Capacity : %d\n", throughputInfo.readCapacityUnits().longValue()); System.out.format(" Write Capacity: %d\n", throughputInfo.writeCapacityUnits().longValue()); List<AttributeDefinition> attributes = tableInfo.attributeDefinitions(); System.out.println("Attributes"); for (AttributeDefinition a : attributes) { System.out.format(" %s (%s)\n", a.attributeName(), a.attributeType()); } } } catch (DynamoDbException e) { System.err.println(e.getMessage()); System.exit(1); } System.out.println("\nDone!"); }
  • For API details, see DescribeTable in Amazon SDK for Java 2.x API Reference.

JavaScript
SDK for JavaScript V3
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the Amazon Code Examples Repository.

Create the client.

// Create service client module using ES6 syntax. import { DynamoDBClient } from "@aws-sdk/client-dynamodb"; // Set the AWS Region. const REGION = "REGION"; //e.g. "us-east-1" // Create an Amazon DynamoDB service client object. const ddbClient = new DynamoDBClient({ region: REGION }); export { ddbClient };

Describe the table.

// Import required AWS SDK clients and commands for Node.js import { DescribeTableCommand } from "@aws-sdk/client-dynamodb"; import { ddbClient } from "./libs/ddbClient.js"; // Set the parameters export const params = { TableName: "TABLE_NAME" }; //TABLE_NAME export const run = async () => { try { const data = await ddbClient.send(new DescribeTableCommand(params)); console.log("Success", data); // console.log("Success", data.Table.KeySchema); return data; } catch (err) { console.log("Error", err); } }; run();
SDK for JavaScript V2
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the Amazon Code Examples Repository.

// Load the AWS SDK for Node.js var AWS = require('aws-sdk'); // Set the region AWS.config.update({region: 'REGION'}); // Create the DynamoDB service object var ddb = new AWS.DynamoDB({apiVersion: '2012-08-10'}); var params = { TableName: process.argv[2] }; // Call DynamoDB to retrieve the selected table descriptions ddb.describeTable(params, function(err, data) { if (err) { console.log("Error", err); } else { console.log("Success", data.Table.KeySchema); } });
Python
SDK for Python (Boto3)
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the Amazon Code Examples Repository.

class Movies: """Encapsulates an Amazon DynamoDB table of movie data.""" def __init__(self, dyn_resource): """ :param dyn_resource: A Boto3 DynamoDB resource. """ self.dyn_resource = dyn_resource self.table = None def exists(self, table_name): """ Determines whether a table exists. As a side effect, stores the table in a member variable. :param table_name: The name of the table to check. :return: True when the table exists; otherwise, False. """ try: table = self.dyn_resource.Table(table_name) table.load() exists = True except ClientError as err: if err.response['Error']['Code'] == 'ResourceNotFoundException': exists = False else: logger.error( "Couldn't check for existence of %s. Here's why: %s: %s", table_name, err.response['Error']['Code'], err.response['Error']['Message']) raise else: self.table = table return exists
  • For API details, see DescribeTable in Amazon SDK for Python (Boto3) API Reference.

Ruby
SDK for Ruby
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the Amazon Code Examples Repository.

# 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) table = Aws::DynamoDB::Table.new(table_name) table.load @table = table rescue Aws::DynamoDB::Errors::ResourceNotFoundException puts("Table #{table_name} doesn't exist. Let's create it.") false rescue Aws::Errors::ServiceError => e puts("Couldn't check for existence of #{table_name}. Here's why:") puts("\t#{e.code}: #{e.message}") raise else !@table.nil? end
  • For API details, see DescribeTable in Amazon SDK for Ruby API Reference.

For a complete list of Amazon SDK developer guides and code examples, see Using DynamoDB with an Amazon SDK. This topic also includes information about getting started and details about previous SDK versions.