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ABAP CDS - Data Definitions

CDS data definitions are created using the CDS DDL of the ABAP CDS in the DDL source code. CDS data definitions can be used to define (and possibly enhance) CDS entities:

A CDS entity is a structured ABAP CDS object managed by ABAP Dictionary. When a CDS data definition is activated, it is created as metadata in DDL source code. The CDS entities themselves are not transported. Instead they are created after the transport of a DDL source code when this code is activated in the target system. Each CDS entity is defined in a separate piece of DDL source code in the ABAP Development Tools (ADT). In the development tools, CDS entities are only visible as CDS definitions in their DDL source code. The ABAP Dictionary tool in ABAP Workbench (SE11) does not support any CDS data definitions of CDS entities. The ABAP runtime environment and other frameworks access the internal metadata of CDS entities. For example, the ABAP runtime environment recognizes a CDS entity as a data type of ABAP Dictionary or as a potential data source of Open SQL statements. The name of a CDS must be unique accordingly.

A CDS entity represents a structured type as a data type in ABAP Dictionary. In ABAP CDS, the CDS entity can be used as a data source in other CDS entities. In ABAP, a CDS entity can be specified after the TYPE addition to reference this structure type and its components in ABAP programs. The components of the structured type are, as usual, specified using the structure component selector cds_entity-comp. CDS entities can be accessed In Open SQL read statements but not in Native SQL or AMDP.

A CDS entity cannot be used as a data type in ABAP Dictionary. It cannot, for example, be used as a type of a substructure, as an include structure, or as the row type of a table type.

The following sections describe the possible CDS entities and the associated DDL statements:

A further section describes the problems that can arise due to cyclical dependencies between CDS entities.

Notes

The same applies to the DDL source code of a CDS view extension and its append view.


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ABAP CDS - Views
ABAP CDS - Table Functions
ABAP CDS - DDL for Data Definitions
ABAP CDS - Cyclical Dependencies