Working with DynamoDB tables in .NET

You can use the Amazon 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 Amazon SDK for .NET.

Creating a table

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

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.

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.

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.

The following C# example demonstrates the preceding steps.

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.

The following C# code example demonstrates the preceding steps.

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 Amazon 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.

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);