DynamoDB. Additional On Update behavior for particular attribute.

[uraniumdawn]

Describe the feature

Current SDK v2 has UpdateBehavior enum. It contains only WRITE_ALWAYS and WRITE_IF_NOT_EXISTS. It would be great to have additional enum to define the updated policy for elements in the collection attribute's type as like Set/List. Something like list_appent() in update expression but for DynamoDbBean

Is your Feature Request related to a problem?

No.

Proposed Solution

Additional enum APPEND_ON_COLLECTION inside of UpadteBehavior annotation applied only for Set/List attribute.
On UpdateItem action all elements of the collection's attribute should add to the existing ones. In the List case elements can contain duplicates and don't contain in the Set case.

Describe alternatives you've considered

No response

Acknowledge

• I may be able to implement this feature request

AWS Java SDK version used

2.17.97

JDK version used

openjdk 11.0.13 2021-10-19 OpenJDK Runtime Environment Temurin-11.0.13+8 (build 11.0.13+8) OpenJDK 64-Bit Server VM Temurin-11.0.13+8 (build 11.0.13+8, mixed mode)

Operating System and version

MacOS 12.0.1

[debora-ito]

Hi @uraniumdawn thank you for reaching out.

You mean like this list_append function for update expression, correct? -
https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.UpdateExpressions.html#Expressions.UpdateExpressions.SET.UpdatingListElements

[uraniumdawn]

@debora-ito Exactly.