In a transactional application using the ABAP RESTful Application Programming Model (RAP), where should field name mapping be defined?

In a transactional application utilizing the ABAP RESTful Application Programming Model (RAP), field name mapping is essential for defining how fields from different layers or structures correspond to one another. The correct place to define this mapping is in the Behavior Definition. This is because the Behavior Definition serves as the central point where the business logic and behavior of the data model are defined, including the mapping of fields from the database to the application layer.

When you define the Behavior Definition, you essentially outline how the application should behave concerning the underlying data model, and this includes specifying field names and their mappings. The Behavior Definition provides a framework that connects the application logic with the data and its representation, ensuring that the application functions correctly when it accesses these fields.

The Behavior Projection, Behavior Implementation, and field mapping view, while essential components of the RAP, serve different purposes. The Behavior Projection focuses on exposing the behavior of a business object to consumers without directly handling the underlying data mappings. The Behavior Implementation contains the actual coding and implementation logic for the behaviors defined in the Behavior Definition. The field mapping view is typically used to provide a specific view on the data for front-end applications but is not where the field mappings between the database and the application models are fundamentally defined.

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