ABAP CDS on HANA-13

ABAP CDS View Types & Annotation Types

 

 

 

Different CDS views  types are allowed to create and those are :-

1. Basic– Views that form the core data basis without data redundancies.
2. Composite– Views that provide data derived and/or composed from the BASIC views.
3. Consumption– Views that serve for specific application purposes and may be defined based upon public interface (for example, BASIC and COMPOSITE) views.
4. Extension– A HANA view can be used as abap CDS view called Extension view.

A CDS interface view cam be made as Public or private. Private interface (for example, BASIC & COMPOSITE) views represent technical helper views which may only be used by their defining responsibilities.

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CDS Annotations: A CDS annotation adds metadata to the view that expands the syntax options of SQL.

1. Core annotations – It can be specified in the source code of any ABAP CDS object & are evaluated by  run time environment.
2. UI annotations -It  allows to focus OData UI vocabulary on usage patterns of data in UIs representing certain semantic views of  data. The UI annotations used are evaluated by the SADL framework, which means that SADL translates CDS annotations into the corresponding OData annotations.
3. Search annotations – It allows to define search fields as filters . The annotations used are also evaluated by the SADL framework.
4. Analytics annotations – It provides data elements with aggregation behavior in analytical scenarios.

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An example of – a Public BASIC CDS Interface View

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@VDM.viewType: #BASIC

define view Flight ... { key Carrid, ... }

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An example of – a Private  COMPOSITE CDS Interface View

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@VDM.private: true

@VDM.viewType: #COMPOSITE

define view FlightDetails ... { key Carrid, ... }

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