Working with DynamoDB Tables in .NET - Amazon DynamoDB

Working with DynamoDB Tables in .NET

You can use the AWS SDK for .NET to create, update, and delete tables, list all the tables in your account, or get information about a specific table.

The following are the common steps for Amazon DynamoDB table operations using the AWS SDK for .NET.

  1. Create an instance of the AmazonDynamoDBClient class (the client).

  2. Provide the required and optional parameters for the operation by creating the corresponding request objects.

    For example, create a CreateTableRequest object to create a table and UpdateTableRequest object to update an existing table.

  3. Run the appropriate method provided by the client that you created in the preceding step.

Note

The examples in this section don't work with .NET core because it doesn't support synchronous methods. For more information, see AWS Asynchronous APIs for .NET.

Creating a Table

To create a table, you must provide the table name, its primary key, and the provisioned throughput values.

To create a table using the AWS SDK for .NET low-level API

  1. Create an instance of the AmazonDynamoDBClient class.

  2. Create an instance of the CreateTableRequest class to provide the request information.

    You must provide the table name, primary key, and the provisioned throughput values.

  3. Run the AmazonDynamoDBClient.CreateTable method by providing the request object as a parameter.

The following C# example demonstrates the preceding steps. The sample creates a table (ProductCatalog) that uses Id as the primary key and set of provisioned throughput values. Depending on your application requirements, you can update the provisioned throughput values by using the UpdateTable API.

AmazonDynamoDBClient client = new AmazonDynamoDBClient(); string tableName = "ProductCatalog"; var request = new CreateTableRequest { TableName = tableName, AttributeDefinitions = new List<AttributeDefinition>() { new AttributeDefinition { AttributeName = "Id", AttributeType = "N" } }, KeySchema = new List<KeySchemaElement>() { new KeySchemaElement { AttributeName = "Id", KeyType = "HASH" //Partition key } }, ProvisionedThroughput = new ProvisionedThroughput { ReadCapacityUnits = 10, WriteCapacityUnits = 5 } }; var response = client.CreateTable(request);

You must wait until DynamoDB creates the table and sets its status to ACTIVE. The CreateTable response includes the TableDescription property that provides the necessary table information.

Example

var result = response.CreateTableResult; var tableDescription = result.TableDescription; Console.WriteLine("{1}: {0} \t ReadCapacityUnits: {2} \t WriteCapacityUnits: {3}", tableDescription.TableStatus, tableDescription.TableName, tableDescription.ProvisionedThroughput.ReadCapacityUnits, tableDescription.ProvisionedThroughput.WriteCapacityUnits); string status = tableDescription.TableStatus; Console.WriteLine(tableName + " - " + status);

You can also call the DescribeTable method of the client to get table information at any time.

Example

var res = client.DescribeTable(new DescribeTableRequest{TableName = "ProductCatalog"});

Updating a Table

You can update only the provisioned throughput values of an existing table. Depending on your application requirements, you might need to update these values.

Note

You can increase throughput capacity as often as needed, and decrease it within certain constraints. For more information about throughput increases and decreases per day, see Service, Account, and Table Quotas in Amazon DynamoDB.

To update a table using the AWS SDK for .NET low-level API

  1. Create an instance of the AmazonDynamoDBClient class.

  2. Create an instance of the UpdateTableRequest class to provide the request information.

    You must provide the table name and the new provisioned throughput values.

  3. Run the AmazonDynamoDBClient.UpdateTable method by providing the request object as a parameter.

The following C# example demonstrates the preceding steps.

Example

AmazonDynamoDBClient client = new AmazonDynamoDBClient(); string tableName = "ExampleTable"; var request = new UpdateTableRequest() { TableName = tableName, ProvisionedThroughput = new ProvisionedThroughput() { // Provide new values. ReadCapacityUnits = 20, WriteCapacityUnits = 10 } }; var response = client.UpdateTable(request);

Deleting a Table

Follow these steps to delete a table using the .NET low-level API.

To delete a table using the AWS SDK for .NET low-level API

  1. Create an instance of the AmazonDynamoDBClient class.

  2. Create an instance of the DeleteTableRequest class, and provide the table name that you want to delete.

  3. Run the AmazonDynamoDBClient.DeleteTable method by providing the request object as a parameter.

The following C# code example demonstrates the preceding steps.

Example

AmazonDynamoDBClient client = new AmazonDynamoDBClient(); string tableName = "ExampleTable"; var request = new DeleteTableRequest{ TableName = tableName }; var response = client.DeleteTable(request);

Listing Tables

To list tables in your account using the AWS SDK for .NET low-level API, create an instance of the AmazonDynamoDBClient and run the ListTables method.

The ListTables operation requires no parameters. However, you can specify optional parameters. For example, you can set the Limit parameter if you want to use paging to limit the number of table names per page. This requires you to create a ListTablesRequest object and provide optional parameters as shown in the following C# example. Along with the page size, the request sets the ExclusiveStartTableName parameter. Initially, ExclusiveStartTableName is null. However, after fetching the first page of results, to retrieve the next page of results, you must set this parameter value to the LastEvaluatedTableName property of the current result.

Example

AmazonDynamoDBClient client = new AmazonDynamoDBClient(); // Initial value for the first page of table names. string lastEvaluatedTableName = null; do { // Create a request object to specify optional parameters. var request = new ListTablesRequest { Limit = 10, // Page size. ExclusiveStartTableName = lastEvaluatedTableName }; var response = client.ListTables(request); ListTablesResult result = response.ListTablesResult; foreach (string name in result.TableNames) Console.WriteLine(name); lastEvaluatedTableName = result.LastEvaluatedTableName; } while (lastEvaluatedTableName != null);