New Release C_ABAPD_2309 SAP Certified Associate Questions

After you created a database table in the RESTful Application Programming model (RAP), the next step is to create a projection view on the database table. A projection view is a CDS artefact that defines a view on one or more data sources, such as tables, views, or associations. A projection view can select, rename, or aggregate the fields of the data sources, but it cannot change the properties of the fields, such as whether they are read-only or not. The properties of the fields are inherited from the data sources or the behaviour definitions of the business objects12. For example:

The following code snippet defines a projection view ZI_AGENCY on the database table /DMO/AGENCY:

define view ZI_AGENCY as select from /dmo/agency { key agency_id, agency_name, street, city, region, postal_code, country, phone_number, url }

The projection view is used to expose the data of the database table to the service definition, which is the next step in the RAP. The service definition is a CDS artefact that defines the interface and the binding of a service. A service is a CDS entity that exposes the data and the functionality of one or more business objects as OData, InA, or SQL services. A service definition can specify the properties of the fields of a service, such as whether they are filterable, sortable, or aggregatable12. For example:

The following code snippet defines a service definition ZI_AGENCY_SRV that exposes the projection view ZI_AGENCY as an OData service:

define service ZI_AGENCY_SRV { expose ZI_AGENCY as Agency; }

You cannot do any of the following:

A. A metadata extension: A metadata extension is a CDS artefact that defines additional annotations for a CDS entity, such as a business object, a service, or a projection view. A metadata extension can specify the properties of the fields of a CDS entity for UI or analytical purposes, such as whether they are visible, editable, or hidden. However, a metadata extension is not the next step after creating a database table in the RAP, as it is not required to expose the data of the database table to the service definition. A metadata extension can be created later to customize the UI or analytical application that uses the service12.

C. A data model view: A data model view is a CDS artefact that defines a view on one or more data sources, such as tables, views, or associations. A data model view can select, rename, or aggregate the fields of the data sources, and it can also change the properties of the fields, such as whether they are read-only or not. The properties of the fields are defined by the annotations or the behaviour definitions of the data model view. A data model view is used to define the data model of a business object, which is a CDS entity that represents a business entity or concept, such as a customer, an order, or a product. However, a data model view is not the next step after creating a database table in the RAP, as it is not required to expose the data of the database table to the service definition. A data model view can be created later to define a business object that uses the database table as a data source12.

D. A service definition: A service definition is a CDS artefact that defines the interface and the binding of a service. A service is a CDS entity that exposes the data and the functionality of one or more business objects as OData, InA, or SQL services. A service definition can specify the properties of the fields of a service, such as whether they are filterable, sortable, or aggregatable. However, a service definition is not the next step after creating a database table in the RAP, as it requires a projection view or a data model view to expose the data of the database table. A service definition can be created after creating a projection view or a data model view on the database table12.

References: 1: ABAP CDS - Data Definitions - ABAP Keyword Documentation - SAP Online Help 2: ABAP CDS - Service Definitions - ABAP Keyword Documentation - SAP Online Help

In a RESTful Application Programming (RAP) application, you can bind a CDS view to create a value help in the following objects:

Data model view: A data model view is a CDS view that defines the data structure and the associations of an entity in the RAP application. You can use the annotation @Consumption.valueHelpDefinition to bind a value help provider CDS view to an element of the data model view. The value help provider CDS view must contain the key fields of the value help entity and the fields that are displayed in the value help dialog. The value help annotation specifies the entity name, the element name, and optionally the additional binding conditions for the value help provider1.

Metadata Extension: A metadata extension is a CDS view that extends the metadata of another CDS view without changing its data structure. You can use the annotation @MetadataExtension.extendView to specify the target CDS view that you want to extend. You can then use the same annotation @Consumption.valueHelpDefinition to bind a value help provider CDS view to an element of the target CDS view. The metadata extension allows you to add value help definitions to existing CDS views without modifying them2.

Projection View: A projection view is a CDS view that defines the projection of another CDS view. You can use the annotation @AbapCatalog.sqlViewType: #PROJECTION to specify that the CDS view is a projection view. You can then use the same annotation @Consumption.valueHelpDefinition to bind a value help provider CDS view to an element of the projection view. The projection view allows you to add value help definitions to projected elements of another CDS view3.

You cannot bind a value help provider CDS view to a behavior definition or a service definition, because these objects do not define the data structure or the metadata of an entity in the RAP application. A behavior definition defines the behavior and the validation rules of an entity, such as the create, read, update, and delete (CRUD) operations, the draft handling, the authorization checks, and the side effects4. A service definition defines the service exposure and the service binding of an entity, such as the protocol, the version, the namespace, and the service name5.

References: 1: Value Help with Additional Binding | SAP Help Portal 2: Metadata Extensions - ABAP Keyword Documentation 3: Projection Views - ABAP Keyword Documentation 4: Behavior Definition - ABAP Keyword Documentation 5: Service Definition - ABAP Keyword Documentation

The following are the explanations for each statement:

A: This statement is correct. go_subl = CAST #(go_super) will not work. This is because go_subl is a data object of type REF TO cl_subl, which is a reference to the subclass cl_subl. go_super is a data object of type REF TO cl_super, which is a reference to the superclass cl_super. The CAST operator is used to perform a downcast or an upcast of a reference variable to another reference variable of a compatible type. A downcast is a conversion from a more general type to a more specific type, while an upcast is a conversion from a more specific type to a more general type. In this case, the CAST operator is trying to perform a downcast from go_super to go_subl, but this is not possible, as go_super is not pointing to an instance of cl_subl, but to an instance of cl_super. Therefore, the CAST operator will raise an exception CX_SY_MOVE_CAST_ERROR at runtime12

B: This statement is incorrect. go_sub2 = CAST #(go_super) will work. go_subl = CAST #(go_super) will not work. This is because go_sub2 is a data object of type REF TO cl_sub2, which is a reference to the subclass cl_sub2. go_super is a data object of type REF TO cl_super, which is a reference to the superclass cl_super. The CAST operator is used to perform a downcast or an upcast of a reference variable to another reference variable of a compatible type. A downcast is a conversion from a more general type to a more specific type, while an upcast is a conversion from a more specific type to a more general type. In this case, the CAST operator is trying to perform a downcast from go_super to go_sub2, and this is possible, as go_super is pointing to an instance of cl_sub2, which is a subclass of cl_super. Therefore, the CAST operator will assign the reference of go_super to go_sub2 without raising an exception. However, the CAST operator will not work for go_subl, as explained in statement A12

C: This statement is incorrect. go_sub2 = CAST #(go_super) will work. go_sub2->sub2_meth1(…) will not work. This is because go_sub2 is a data object of type REF TO cl_sub2, which is a reference to the subclass cl_sub2. go_super is a data object of type REF TO cl_super, which is a reference to the superclass cl_super. The CAST operator is used to perform a downcast or an upcast of a reference variable to another reference variable of a compatible type. A downcast is a conversion from a more general type to a more specific type, while an upcast is a conversion from a more specific type to a more general type. In this case, the CAST operator is trying to perform a downcast from go_super to go_sub2, and this is possible, as go_super is pointing to an instance of cl_sub2, which is a subclass of cl_super. Therefore, the CAST operator will assign the reference of go_super to go_sub2 without raising an exception. However, the method call go_sub2->sub2_meth1(…) will not work, as sub2_meth1 is a subclass-specific method of cl_sub2, which is not inherited by cl_super. Therefore, the method call will raise an exception CX_SY_DYN_CALL_ILLEGAL_METHOD at runtime123

D: This statement is correct. go_subl->subl_meth1(…) will work. This is because go_subl is a data object of type REF TO cl_subl, which is a reference to the subclass cl_subl. subl_meth1 is a subclass-specific method of cl_subl, which is not inherited by cl_super. Therefore, the method call go_subl->subl_meth1(…) will work, as go_subl is pointing to an instance of cl_subl, which has the method subl_meth1123

References: NEW - ABAP Keyword Documentation, CAST - ABAP Keyword Documentation, Method Call - ABAP Keyword Documentation