Get Example source ABAP code based on a different SAP table
• EXTEND SERVICE ABAP_SDL_DEFINE_SERV • WITH ABAP_CDS_SD_EXT
ABAP_CDS_SDL - EXTEND SERVICE
ABAP_SYNTAX EXTEND SERVICE name WITH { EXPOSE cds_entity1 $[AS alias1$]; $[EXPOSE cds_entity2 $[AS alias2$]; ...$] }
What does it do? Extends an existing CDS service definition name using a CDS service definition extension in the CDS SDL . An existing CDS service definition can have one or more CDS service definition extensions.
ABAP_PREREQUISITE As a prerequisite for service definition extensions, the service definition to be extended must explicitly allow extensions. The annotation @AbapCatalog.extensibility.extensible must be set to true . ABAP_PREREQ_END
Rules for a Service Definition Extension Service definition extensions can make additions to the original service definition, but they cannot modify, overwrite, or delete elements from it. The following rules apply:
CDS entities cds_entity1, cds_entity2, ... can be exposed using the keyword EXPOSE. The same rules apply as to the original service definition, see topic TITLE .
Each exposed entity must have a unique name across the original service definition and all existing extensions. In case of naming conflicts, an alternative element alias1 must be assigned using the addition AS.
The exposed entities cds_entity1, cds_entity2, ... can be entities from the original data model or extension entities. The names of the exposed entities must comply with the namespace of the service definition extension. For example, if the name of a service definition extension starts with a Z, each exposed entity must also have a name that starts with Z. This can also be achieved by assigning an alias name with the addition AS.
If exposed, each entity should be exposed only once in a service definition and any of its extensions. Even if a new alias name is assigned, a syntax check warning occurs if an entity is exposed more than once.
ABAP_RESTRICTIONS
CDS service definition extensions themselves cannot be extended.
Service definition annotations are not supported. That means that no annotations are allowed in front of the statement EXTEND SERVICE. ABAP_RESTR_END
ABAP_EXAMPLE_VX5 The following CDS service definition extension SRVD DEMO_CDS_EXTENSION_SD adds one further entity to the service definition SRVD DEMO_CDS_ORIGINAL_SD ABAP_EXAMPLE_END
