AWS SDK for .NET Documentation
UpdateItem Method (updateItemRequest)
AmazonAmazon.DynamoDBv2AmazonDynamoDBClientUpdateItem(UpdateItemRequest) Did this page help you?   Yes   No    Tell us about it...

Edits an existing item's attributes, or inserts a new item if it does not already exist. You can put, delete, or add attribute values. You can also perform a conditional update (insert a new attribute name-value pair if it doesn't exist, or replace an existing name-value pair if it has certain expected attribute values).

In addition to updating an item, you can also return the item's attribute values in the same operation, using the ReturnValues parameter.

Declaration Syntax
C#
public UpdateItemResponse UpdateItem(
	UpdateItemRequest updateItemRequest
)
Parameters
updateItemRequest (UpdateItemRequest)
Container for the necessary parameters to execute the UpdateItem service method on AmazonDynamoDBv2.
Return Value
The response from the UpdateItem service method, as returned by AmazonDynamoDBv2.
Examples

This example shows how to update an item in a table.

CopyUpdateItem sample
// Create a client
AmazonDynamoDBClient client = new AmazonDynamoDBClient();

// Define item key
//  Hash-key of the target item is string value "Mark Twain"
//  Range-key of the target item is string value "The Adventures of Tom Sawyer"
Dictionary<string, AttributeValue> key = new Dictionary<string, AttributeValue>
{
    { "Author", new AttributeValue { S = "Mark Twain" } },
    { "Title", new AttributeValue { S = "The Adventures of Tom Sawyer" } }
};

// Define attribute updates
Dictionary<string, AttributeValueUpdate> updates = new Dictionary<string, AttributeValueUpdate>();
// Update item's Setting attribute
updates["Setting"] = new AttributeValueUpdate()
    .WithAction("PUT")
    .WithValue(new AttributeValue { S = "St. Petersburg, Missouri" });
// Remove item's Bibliography attribute
updates["Bibliography"] = new AttributeValueUpdate()
    .WithAction("DELETE");
// Add a new string to the item's Genres SS attribute
updates["Genres"] = new AttributeValueUpdate()
    .WithAction("ADD")
    .WithValue(new AttributeValue { SS = new List<string> { "Bildungsroman" } });

// Create UpdateItem request
UpdateItemRequest request = new UpdateItemRequest
{
    TableName = "SampleTable",
    Key = key,
    AttributeUpdates = updates
};

// Issue request
client.UpdateItem(request);
Exceptions

Assembly: AWSSDK (Module: AWSSDK) Version: 1.5.60.0 (1.5.60.0)