User guide

Console.WriteLine(jsonPrettyText);

// Output:

// {

// "Name" : "Shadow",

// "Type" : "Horse",

// "Id" : 3

// }

In the preceding example, the Document class's ToJson method converts an item from the table into a

JSON-formatted string. The item is retrieved through the Table class's GetItem method.To determine

the item to get, in this example, the GetItem method uses the hash-and-range primary key of the target

item.To determine the table to get the item from, the Table class's LoadTable method uses an instance

of the AmazonDynamoDBClient class and the name of the target table in DynamoDB.

Insert JSON Format Data into a DynamoDB Table

The following example shows how to use JSON format to insert an item into a DynamoDB table:

// using Amazon.DynamoDBv2;

// using Amazon.DynamoDBv2.DocumentModel;

var client = new AmazonDynamoDBClient();

var table = Table.LoadTable(client, "AnimalsInventory");

var jsonText = "{\"Id\":6,\"Type\":\"Bird\",\"Name\":\"Tweety\"}";

var item = Document.FromJson(jsonText);

table.PutItem(item);

In the preceding example, the Document class's FromJson method converts a JSON-formatted string

into an item. The item is inserted into the table through the Table class's PutItem method, which uses

the instance of the Document class that contains the item. To determine the table to insert the item into,

the Table class's LoadTable method is called, specifying an instance of the AmazonDynamoDBClient

class and the name of the target table in DynamoDB.

DynamoDB Data Type Conversions to JSON

Whenever you call the Document class's ToJson method, and then on the resulting JSON data you call

the FromJson method to convert the JSON data back into an instance of a Document class, some

DynamoDB data types will not convert as expected. Specifically:

• DynamoDB sets (the SS, NS, and BS types) will be converted to JSON arrays.

• DynamoDB binary scalars and sets (the B and BS types) will be converted to base64-encoded JSON

strings or lists of strings.

In this scenario, you must call the Document class's DecodeBase64Attributes method to replace

the base64-encoded JSON data with the correct binary representation.The following example replaces

a base64-encoded binary scalar item attribute in an instance of a Document class, named Picture,

with the correct binary representation.This example also does the same for a base64-encoded binary

set item attribute in the same instance of the Document class, named RelatedPictures:

item.DecodeBase64Attributes("Picture", "RelatedPictures");

Version v2.0.0

AWS SDK for .NET Developer Guide

JSON Support in Amazon DynamoDB