DynamoDB Auto Generate Timestamp

DynamoDB supports the use of the @DynamoDBAutoGenerateTimestamp annotation to automatically populate a timestamp attribute when an item is created or updated in a DynamoDB table. However, this annotation only works on top-level attributes of an item, not on nested attributes within a DynamoDBDocument.

To fix this, you can have a few options:

One approach is to extract the "Note" entity out of the "Post" table and create a new table for it. Then you can use the @DynamoDBAutoGenerateTimestamp annotation on the "createdAt" attribute in the "Note" table. Another option is to use a Lambda function that is triggered by the DynamoDB Streams of the "Post" table. The Lambda function can check if the "createdAt" attribute in the "Note" entity is null, and if so, set it to the current timestamp before storing the item in the "Post" table. You can write a code in the application layer that will populate the createdAt field with the current timestamp before storing the item in the "Post" table. By using one of the above options, you should be able to automatically populate the "createdAt" attribute in the "Note" entity when an item is stored in the "Post" table.

"@DynamoDBAutoGenerateTimestamp" has a typo, did you actually use "@DynamoDBAutoGeneratedTimestamp"?