AWS SDK for .NET Documentation
Action Property
AmazonAmazon.DynamoDB.ModelAttributeValueUpdateAction Did this page help you?   Yes   No    Tell us about it...
The type of action for an item update operation. Only use the add action for numbers or sets; the specified value is added to the existing value. If a set of values is specified, the values are added to the existing set. Adds the specified attribute. If the attribute exists, it is replaced by the new value. If no value is specified, this removes the attribute and its value. If a set of values is specified, then the values in the specified set are removed from the old set.

Constraints:

Allowed Values
ADD, PUT, DELETE

Declaration Syntax
C#
public string Action { get; set; }

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