ABAP CDS Basics
What is ABAP CDS?
ABAP CDS provides a framework for defining and consuming semantic data models on the DB of the ABAP AS. The data models are based on data definition language[DDL] and data control language[DCL].
What are ABAP CDS Entities?
ABAP CDS Entities are models based on the data definition language[DDL] and managed by the ABAP Dictionary.
The ABAP CDS Entities are:
- ABAP CDS Views
- ABAP CDS Table Functions
What is ABAP CDS View?
A CDS view is defined on the existing database tables/views/other cds views in ABAP dictionary using specific DDL statement Define View. It serves to define the structure of the CDS database view and represents a project on several database tables/views in ABAP dictionary.
A CDS View associated with the CDS Data Base View and the CDS entity are part of same namespace, so different names must be assigned to the database view and to the cds entity.
When a CDS View is activated it creates following objects in ABAP dictionary:
- Actual CDS Entity
- CDS Database View
CDS View Building Architecture
What is ABAP CDS Table Functions:
These are table functions that are implemented natively on the database and can be called in CDS view. They support code push down capabilities in ABAP CDS.
A CDS Table Function is defined using statement DEFINE TABLE FUNCTION . In contrast to the CDS views , the CDS table functions can be implemented by using native SQL . The implementation is done within AMDP method of the AMDP class and is managed as an AMDP function by the AMDP framework in the DB.