Working with the .NET document model in DynamoDB - Amazon DynamoDB
Supported data types

Working with the .NET document model in DynamoDB

The AWS SDK for .NET provides document model classes that wrap some of the low-level Amazon DynamoDB operations, further simplifying your coding. In the document model, the primary classes are Table and Document. The Table class provides data operation methods such as PutItem, GetItem, and DeleteItem. It also provides the Query and the Scan methods. The Document class represents a single item in a table.

The preceding document model classes are available in the Amazon.DynamoDBv2.DocumentModel namespace.

Note

You can't use the document model classes to create, update, and delete tables. However, the document model does support most common data operations.

Supported data types

The document model supports a set of primitive .NET data types and collections data types. The model supports the following primitive data types.

  • bool

  • byte

  • char

  • DateTime

  • decimal

  • double

  • float

  • Guid

  • Int16

  • Int32

  • Int64

  • SByte

  • string

  • UInt16

  • UInt32

  • UInt64

The following table summarizes the mapping of the preceding .NET types to the DynamoDB types.

.NET primitive type DynamoDB type

All number types

N (number type)

All string types

S (string type)

MemoryStream, byte[]

B (binary type)

bool N (number type). 0 represents false and 1 represents true.
DateTime S (string type). The DateTime values are stored as ISO-8601 formatted strings.
Guid S (string type).
Collection types (List, HashSet, and array) BS (binary set) type, SS (string set) type, and NS (number set) type

AWS SDK for .NET defines types for mapping DynamoDB's Boolean, null, list and map types to .NET document model API:

  • Use DynamoDBBool for Boolean type.

  • Use DynamoDBNull for null type.

  • Use DynamoDBList for list type.

  • Use Document for map type.

Note

  • Empty binary values are supported.

  • Reading of empty string values is supported. Empty string attribute values are supported within attribute values of string Set type while writing to DynamoDB. Empty string attribute values of string type and empty string values contained within List or Map type are dropped from write requests