C_ABAPD_2309 SAP Certified Associate - Back-End Developer - ABAP Cloud Questions and Answers

The following are the integration frameworks that have been released for ABAP cloud development:

SOAP consumption: This framework allows you to consume SOAP web services from ABAP cloud applications. You can use the ABAP Development Tools in Eclipse to create a service consumption model based on a WSDL file or URL. The service consumption model generates the required ABAP artifacts, such as proxy classes, data types, and constants, to access the web service. You can then use the proxy classes to call the web service operations from your ABAP code1

Business Events: This framework allows you to publish and subscribe to business events from ABAP cloud applications. Business events are messages that represent a change in the state of a business object or process. You can use the ABAP Development Tools in Eclipse to create a business event definition based on a CDS view entity or a projection view. The business event definition specifies the event key, the event payload, and the event metadata. You can then use the ABAP Messaging Channel (AMC) framework to publish and subscribe to business events using the AMC API2

OData services: This framework allows you to expose and consume OData services from ABAP cloud applications. OData is a standardized protocol for creating and consuming RESTful APIs. You can use the ABAP RESTful Application Programming Model (RAP) to create OData services based on CDS view entities or projection views. The RAP framework generates the required OData metadata and runtime artifacts, such as service definitions, service bindings, and service implementations. You can then use the SAP Gateway framework to register and activate your OData services. You can also use the ABAP Development Tools in Eclipse to consume OData services from other sources using the service consumption model3

The other integration frameworks are not released for ABAP cloud development, as they are either not supported or not recommended for cloud scenarios. These frameworks are:

CDS Views: CDS views are not an integration framework, but a data modeling framework. CDS views are used to define data models based on database tables or other CDS view entities. CDS views can have associations, aggregations, filters, parameters, and annotations. CDS views can also be used as the basis for other integration frameworks, such as OData services or business events4

Business Add-ins (BAdls): BAdls are not supported for ABAP cloud development, as they are part of the classic ABAP enhancement framework. BAdls are used to implement custom logic in predefined enhancement spots in the standard SAP code. BAdls are not compatible with the cloud strategy and the clean core paradigm, as they modify the SAP code and can cause upgrade and maintenance issues. For ABAP cloud development, SAP recommends using the key user extensibility tools or the side-by-side extensibility approach instead of BAdls.

References: Consuming SOAP Services - ABAP Keyword Documentation, Business Events - ABAP Keyword Documentation, OData Services - ABAP Keyword Documentation, CDS Data Model Views - ABAP Keyword Documentation, [Business Add-Ins (BAdIs) - ABAP Keyword Documentation]

A unique secondary key is a type of secondary key that ensures that the key combination of all the rows in a table is unique. A unique secondary key has two purposes: firstly, to speed up access to the table, and secondly, to enforce data integrity1.

It is created with the first read access of a table: This is true. A unique secondary key is created when an internal table is filled for the first time using the statement READ TABLE or a similar statement. The system assigns a name and an index to each row of the table based on the key fields23.

It is updated when the modified table is read again: This is false. A unique secondary key does not need to be updated when the internal table content changes, because it already ensures data uniqueness. The system uses a lazy update strategy for non-unique secondary keys, which means that it delays updating them until they are actually accessed23.

You cannot do any of the following:

It is created when a table is filled: This is false. As explained above, a unique secondary key is created only with the first read access of a table23.

It is updated when the modified table is read again: This is false. As explained above, a unique secondary key does not need to be updated when the internal table content changes23.

References: 1: Improving Internal Table Performance Using Secondary Keys - SAP Learning 2: [Secondary Key - ABAP Keyword Documentation - SAP Online Help] 3: [Secondary Table Key - ABAP Keyword Documentation - SAP Online Help]

The following are the explanations for each ABAP SQL statement:

A: This statement is valid. It selects the fields carrid, airpfrom, and the aggregate functions MAX(distance) and MIN(distance) from the table /dmo/connection, and groups the results by carrid and airpfrom. The aggregate functions are aliased as dist_max and dist_min. The results are stored in an internal table named It_hits, which is created using the inline declaration operator @DATA.

B: This statement is valid. It is similar to statement A, except that it does not specify the GROUP BY clause. This means that the aggregate functions are applied to the entire table, and the results are stored in an internal table named It_hits, which is created using the inline declaration operator @DATA.

C: This statement is invalid. It selects the aggregate functions MAX(distance) and MIN(distance) from the table /dmo/connection, but it does not specify any grouping or non-aggregate fields. This is not allowed in ABAP SQL, as the SELECT list must contain at least one non-aggregate field or a GROUP BY clause. The statement will cause a syntax error.

D: This statement is invalid. It selects the fields carrid and airpfrom from the table /dmo/connection, and groups the results by carrid and connid. However, the field connid is not included in the SELECT list, which is not allowed in ABAP SQL, as the GROUP BY clause must contain only fields that are also in the SELECT list. The statement will cause a syntax error.

References: SELECT - ABAP Keyword Documentation, GROUP BY - ABAP Keyword Documentation

The following are the explanations for each statement:

A: This statement is valid. go_ifl may call method ml with go_ifl->ml(). This is because go_ifl is a data object of type REF TO ifl, which is a reference to the interface ifl. The interface ifl defines a method ml, which can be called using the reference variable go_ifl. The class cll implements the interface ifl, which means that it provides an implementation of the method ml. The data object go_ifl is assigned to a new instance of the class cll using the NEW operator and the inline declaration operator @DATA. Therefore, when go_ifl->ml() is called, the implementation of the method ml in the class cll is executed123

B: This statement is valid. Instead of go_cll = NEW #(…) you could use go_ifl = NEW cll(…). This is because go_ifl is a data object of type REF TO ifl, which is a reference to the interface ifl. The class cll implements the interface ifl, which means that it is compatible with the interface ifl. Therefore, go_ifl can be assigned to a new instance of the class cll using the NEW operator and the class name cll. The inline declaration operator @DATA is optional in this case, as go_ifl is already declared. The parentheses after the class name cll can be used to pass parameters to the constructor of the class cll, if any123

E: This statement is valid. go_ifl may call method m2 with go_ifl->m2(…). This is because go_ifl is a data object of type REF TO ifl, which is a reference to the interface ifl. The class cll implements the interface ifl, which means that it inherits all the components of the interface ifl. The class cll also defines a method m2, which is a public method of the class cll. Therefore, go_ifl can call the method m2 using the reference variable go_ifl. The method m2 is not defined in the interface ifl, but it is accessible through the interface ifl, as the interface ifl is implemented by the class cll. The parentheses after the method name m2 can be used to pass parameters to the method m2, if any123

The other statements are not valid, as they have syntax errors or logical errors. These statements are:

C: This statement is not valid. go_cll may call method ml with go_cll->ifl~ml(). This is because go_cll is a data object of type REF TO cll, which is a reference to the class cll. The class cll implements the interface ifl, which means that it inherits all the components of the interface ifl. The interface ifl defines a method ml, which can be called using the reference variable go_cll. However, the syntax for calling an interface method using a class reference is go_cll->ml(), not go_cll->ifl~ml(). The interface component selector ~ is only used when calling an interface method using an interface reference, such as go_ifl->ifl~ml(). Using the interface component selector ~ with a class reference will cause a syntax error123

D: This statement is not valid. Instead of go_cll = NEW #() you could use go_ifl = NEW #(…). This is because go_ifl is a data object of type REF TO ifl, which is a reference to the interface ifl. The interface ifl cannot be instantiated, as it does not have an implementation. Therefore, go_ifl cannot be assigned to a new instance of the interface ifl using the NEW operator and the inline declaration operator @DATA. This will cause a syntax error or a runtime error. To instantiate an interface, you need to use a class that implements the interface, such as the class cll123

References: INTERFACES - ABAP Keyword Documentation, CLASS - ABAP Keyword Documentation, NEW - ABAP Keyword Documentation

The ABAP Cloud Development Model is the ABAP development model to build cloud-ready business apps, services, and extensions. It comes with SAP BTP and SAP S/4HANA. It works with public or private cloud, and even on-premise1. However, the complete ABAP Cloud Development Model, including the cloud-optimized ABAP language and public local SAP APIs and extension points, is available only in SAP BTP ABAP Environment and in the 2208/2022 versions of the SAP S/4HANA editions1. Therefore, you must use the ABAP Cloud Development Model in SAP BTP, ABAP environment and SAP S/4HANA Cloud, private edition. You can also use it in SAP S/4HANA on premise, but it is not mandatory. You cannot use it in SAP S/4HANA Cloud, public edition, because it does not allow custom ABAP code2. References: 1: ABAP Cloud | SAP Blogs 2: SAP S/4HANA Cloud Extensibility – Overview and Comparison | SAP Blogs

The correct expression to change a given string value ‘mr joe doe’ into ‘JOE’ in an ABAP SQL field list is C. SELECT FROM TABLE dbtabl FIELDS Of1, substring(upper(‘mr joe doe’), 4, 3) AS f2_sub_up, f3,… This expression uses the following SQL functions for strings12:

upper: This function converts all lowercase characters in a string to uppercase. For example, upper(‘mr joe doe’) returns ‘MR JOE DOE’.

substring: This function returns a substring of a given string starting from a specified position and with a specified length. For example, substring(‘MR JOE DOE’, 4, 3) returns ‘JOE’.

AS: This keyword assigns an alias or a temporary name to a field or an expression in the field list. For example, AS f2_sub_up assigns the name f2_sub_up to the expression substring(upper(‘mr joe doe’), 4, 3).

You cannot do any of the following:

A. SELECT FROM TABLE dbtabl FIELDS Of1, upper(left( ‘mr joe doe’, 6)) AS f2_up_left, f3,…: This expression uses the wrong SQL function for strings to get the desired result. The left function returns the leftmost characters of a string with a specified length, ignoring the trailing blanks. For example, left( ‘mr joe doe’, 6) returns ‘mr joe’. Applying the upper function to this result returns ‘MR JOE’, which is not the same as ‘JOE’.

B. SELECT FROM TABLE dbtabl FIELDS Of1, left(lower(substring( ‘mr joe doe’, 4, 3)), 3) AS f2_left_lo_sub, f3,…: This expression uses unnecessary and incorrect SQL functions for strings to get the desired result. The lower function converts all uppercase characters in a string to lowercase. For example, lower(substring( ‘mr joe doe’, 4, 3)) returns ‘joe’. Applying the left function to this result with the same length returns ‘joe’ again, which is not the same as ‘JOE’.

D. SELECT FROM TABLE dbtabl FIELDS Of1, substring(lower(upper( ‘mr joe doe’ ) ), 4, 3) AS f2_sub_lo_up, f3,…: This expression uses unnecessary and incorrect SQL functions for strings to get the desired result. The lower function converts all uppercase characters in a string to lowercase, and the upper function converts all lowercase characters in a string to uppercase. Applying both functions to the same string cancels out the effect of each other and returns the original string. For example, lower(upper( ‘mr joe doe’ ) ) returns ‘mr joe doe’. Applying the substring function to this result returns ‘joe’, which is not the same as ‘JOE’.

References: 1: SQL Functions for Strings - ABAP Keyword Documentation - SAP Online Help 2: sql_func - String Functions - ABAP Keyword Documentation - SAP Online Help

Incomplete ABAP types are types that do not specify all the attributes of a data type, such as the length, the number of decimal places, or the value range. Incomplete types can only be used for the typing of field symbols and formal parameters, not for the definition of data objects or constants. Incomplete types can be either predefined or user-defined1.

The following are incomplete ABAP types:

C. C is a type for character strings with a generic length. The length of the character string has to be specified when a data object or a constant is defined with this type. For example, DATA text TYPE c LENGTH 10 defines a data object named text with a type c and a length of 10 characters2.

D. P is a type for packed numbers with a generic length and a generic number of decimal places. The length and the number of decimal places of the packed number have to be specified when a data object or a constant is defined with this type. For example, DATA amount TYPE p LENGTH 8 DECIMALS 2 defines a data object named amount with a type p, a length of 8 bytes, and 2 decimal places3.

The following are not incomplete ABAP types, because they specify all the attributes of a data type:

A. String is a type for variable-length character strings. The length of the character string is determined at runtime and can vary from 0 to 2,147,483,647 characters. The length does not have to be specified when a data object or a constant is defined with this type. For example, DATA text TYPE string defines a data object named text with a type string and a variable length4.

B. T is a type for time values in the format HHMMSS. The length of the time value is fixed at 6 characters and does not have to be specified when a data object or a constant is defined with this type. For example, DATA time TYPE t defines a data object named time with a type t and a length of 6 characters.

References: 1: Generic ABAP Types - ABAP Keyword Documentation 2: C - ABAP Keyword Documentation 3: P - ABAP Keyword Documentation 4: String - ABAP Keyword Documentation : T - ABAP Keyword Documentation

The possible replacements for “???” in the CDS view entity definition with an input parameter are A. built-in ABAP type and C. A data element. These are the valid types that can be used to specify the data type of an input parameter in a CDS view entity. A built-in ABAP type is a predefined elementary type in the ABAP language, such as abap.char, abap.numc, abap.dec, etc. A data element is a reusable semantic element in the ABAP Dictionary that defines the technical attributes and the meaning of a field12. For example:

The following code snippet defines a CDS view entity with an input parameter currency of type abap.cuky, which is a built-in ABAP type for currency key:

Define view entity Z_CONVERT With parameters currency : abap.cuky as select from … { … }

The following code snippet defines a CDS view entity with an input parameter currency of type waers, which is a data element for currency key:

Define view entity Z_CONVERT With parameters currency : waers as select from … { … }

You cannot do any of the following:

B. A built-in ABAP Dictionary type: This is not a valid type for an input parameter in a CDS view entity. A built-in ABAP Dictionary type is a predefined elementary type in the ABAP Dictionary, such as CHAR, NUMC, DEC, etc. However, these types cannot be used directly in a CDS view entity definition. Instead, they have to be prefixed with abap. to form a built-in ABAP type, as explained above12.

D. A component of an ABAP Dictionary structure: This is not a valid type for an input parameter in a CDS view entity. A component of an ABAP Dictionary structure is a field that belongs to a structure type, which is a complex type that consists of multiple fields. However, an input parameter in a CDS view entity can only be typed with an elementary type, which is a simple type that has no internal structure12.

References: 1: ABAP CDS - SELECT, parameter_list - ABAP Keyword Documentation - SAP Online Help 2: ABAP Data Types - ABAP Keyword Documentation - SAP Online Help

 In class ZCL_CLASS_A, you use the statement DATA var TYPE *** to declare a data object named var with a data type specified by ***. The data type can be any of the following1:

A predefined ABAP type, such as i, f, c, string, xstring, and so on.

A data element from the ABAP Dictionary, such as matnr, carrid, bukrs, and so on. A data element defines the semantic and technical attributes of a data field, such as the domain, the length, the data type, the description, and the value range2.

A domain from the ABAP Dictionary, such as matnr_d, carrid_d, bukrs_d, and so on. A domain defines the technical attributes of a data field, such as the data type, the length, the output length, the number of decimal places, and the value range3.

A type defined globally in a class, an interface, or a type pool, such as zcl_class_b=>type_a, zif_interface_c=>type_b, ztype_pool_d=>type_c, and so on. A global type is a type that is defined in a global repository object and can be used in any program or class4.

A type defined locally in the current class, such as type_a, type_b, type_c, and so on. A local type is a type that is defined in the declaration part of a class and can only be used within the class5.

Therefore, the possible values for *** are B. the name of a data element from the ABAP Dictionary and D. the name of a domain from the ABAP Dictionary. The other options are not valid because:

A. The name of a type defined privately in class ZCL_CLASS_A is a local type and cannot be used with the DATA statement. A local type can only be used with the TYPES statement5.

C. The name of a type defined privately in another class is a private type and cannot be accessed from outside the class. A private type can only be used within the class that defines it.

References: 1: DATA - ABAP Keyword Documentation 2: Data Elements - ABAP Dictionary - SAP Online Help 3: Domains - ABAP Dictionary - SAP Online Help 4: Global Types - ABAP Keyword Documentation 5: Local Types - ABAP Keyword Documentation : Private Types - ABAP Keyword Documentation

Comprehensive and Detailed Step-by-Step Explanation:

Interface Implementation in cl1

The INTERFACES if1 statement in the cl1 definition explicitly declares that cl1 implements the interface if1.

Therefore, option E is correct.

Interface Method Naming in cl1

When an interface is implemented in a class, its methods are accessed using the syntax if1~m1 to distinguish them from other methods in the class.

This makes option C correct.

Usage of if1 in cl2

The DATA mo_if1 TYPE REF TO if1 in cl2 creates a reference variable of type if1. However, it does not mean that cl2 implements or uses the interface if1.

This makes option B incorrect.

Interface Method Naming in cl2

Since cl2 does not implement the interface, it does not inherit its methods. Hence, the method if1~m1 is not available in cl2.

This makes option A incorrect.

Class cl1 and Interface Usage

Class cl1 explicitly states INTERFACES if1, which means it not only implements the interface but also uses it.

This makes option D correct.

References:

SAP ABAP Documentation: Interfaces

SAP Training for Back-End Developer - ABAP Cloud

The object that can be used to set a field to read-only in all applications of the RESTful Application Programming model (RAP) is the behaviour definition. The behaviour definition is a CDS artefact that defines the business logic and the UI behaviour of a business object. A business object is a CDS entity that represents a business entity or concept, such as a customer, an order, or a product. The behaviour definition can specify the properties of the fields of a business object, such as whether they are mandatory, read-only, or transient. These properties are valid for all applications that use the business object, such as transactional, analytical, or draft-enabled apps12. For example:

The following code snippet defines a behaviour definition for a business object ZI_PB_APPLICATION. It sets the field APPLICATION to read-only for all applications that use this business object:

define behavior for ZI_PB_APPLICATION { field ( read only ) APPLICATION; … }

You cannot do any of the following:

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, these properties are only valid for the specific service that uses the business object, not for all applications that use the business object12.

C. Projection view: 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.

D. 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, these properties are only valid for the specific UI or analytical application that uses the metadata extension, not for all applications that use the CDS entity12.

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

The nested join is evaluated from the top to the bottom in the order of the ON conditions. This means that the join expression is formed by assigning each ON condition to the directly preceding JOIN from left to right. The join expression can be parenthesized implicitly or explicitly to show the order of evaluation. In this case, the implicit parentheses are as follows:

SELECT * FROM (a INNER JOIN (b INNER JOIN c ON b~c = c~c) ON a~b = b~b)

This means that the first join expression is b INNER JOIN c ON b~c = c~c, which joins the columns of tables b and c based on the condition that b~c equals c~c. The second join expression is a INNER JOIN (b INNER JOIN c ON b~c = c~c) ON a~b = b~b, which joins the columns of table a and the result of the first join expression based on the condition that a~b equals b~b. The final result set contains all combinations of rows from tables a, b, and c that satisfy both join conditions.

References: 1: SELECT, FROM JOIN - ABAP Keyword Documentation - SAP Online Help

A CDS view is a data definition that defines a data structure and a data selection from one or more data sources. A CDS view consists of several parts, but two of them are:

Extension: An extension is an optional clause that allows a CDS view to extend another CDS view by adding new elements, annotations, or associations. The extension clause has the syntax EXTEND VIEW view_name WITH view_name. The first view_name is the name of the CDS view that is being extended, and the second view_name is the name of the CDS view that is doing the extension1.

Field list: A field list is a mandatory clause that specifies the elements of the CDS view. The field list has the syntax SELECT FROM data_source { element_list }. The data_source is the name of the data source that the CDS view selects data from, and the element_list is a comma-separated list of elements that the CDS view exposes. The elements can be fields of the data source, expressions, associations, or annotations2.

The following example shows a CDS view that extends another CDS view and defines a field list:

@AbapCatalog.sqlViewName: ‘ZCDS_EXT’ define view Z_CDS_Extension extend view Z_CDS_Base with Z_CDS_Extension as select from ztable { // field list key ztable.id as ID, ztable.name as Name, ztable.age as Age, // extension @Semantics.currencyCode: true ztable.currency as Currency }

The other options are not parts of a CDS view, but rather related concepts:

Partitioning attributes: Partitioning attributes are attributes that are used to partition a table into smaller subsets of data. Partitioning attributes are defined in the ABAP Dictionary for transparent tables and can improve the performance and scalability of data access. Partitioning attributes are not part of the CDS view definition, but rather the underlying table definition3.

Semantic table attributes: Semantic table attributes are attributes that provide additional information about the meaning and usage of a table. Semantic table attributes are defined in the ABAP Dictionary for transparent tables and can be used to enhance the data modeling and consumption of the table. Semantic table attributes are not part of the CDS view definition, but rather the underlying table definition4.

References: 1: Extending CDS Views | SAP Help Portal 2: SELECT List - ABAP Keyword Documentation 3: Partitioning Attributes - ABAP Keyword Documentation 4: Semantic Table Attributes - ABAP Keyword Documentation

The sub constructor is the instance constructor of the subclass sub that inherits from the superclass super. The sub constructor has some rules that it must follow when it is defined and implemented12. Some of the valid rules are:

The method signature can be changed: This is true. The sub constructor can have a different method signature than the super constructor, which means that it can have different input parameters, output parameters, or exceptions. However, the sub constructor must still call the super constructor with appropriate actual parameters that match its interface12.

The constructor of super must be called before using any components of your own instance: This is true. The sub constructor must ensure that the super constructor is called explicitly using super->constructor before accessing any instance components of its own class, such as attributes or methods. This is because the super constructor initializes the inherited components of the subclass and sets the self-reference me-> to the current instance12.

You cannot do any of the following:

Import parameters can only be evaluated after calling the constructor of super: This is false. The sub constructor can evaluate its own import parameters before calling the constructor of super, as long as it does not access any instance components of its own class. For example, the sub constructor can use its import parameters to calculate some values or check some conditions that are needed for calling the super constructor12.

Events of your own instance cannot be raised before the registration of a handler in super: This is false. The sub constructor can raise events of its own instance before calling the constructor of super, as long as it does not access any instance components of its own class. For example, the sub constructor can raise an event to notify the consumers of the subclass about some status or error that occurred during the initialization of the subclass12.

References: 1: Inheritance and Constructors - ABAP Keyword Documentation - SAP Online Help 2: Using Static and Instance constructor methods | SAP Blogs

SAP recommends that you eliminate the following types of legacy code when you review modifications as part of an SAP S/4HANA system conversion:

Code that now is identical to a standard SAP object. This type of code is redundant and unnecessary, as it does not provide any additional functionality or customization. It can also cause conflicts or errors during the system conversion, as the standard SAP object may have changed or been replaced in SAP S/4HANA. Therefore, you should delete this type of code and use the standard SAP object instead.

Code that can be redesigned as a key user extension. This type of code is usually related to UI or business logic adaptations that can be achieved using the in-app tools provided by SAP S/4HANA. By redesigning this type of code as a key user extension, you can simplify and standardize your code base, reduce maintenance efforts, and avoid compatibility issues during the system conversion. Therefore, you should migrate this type of code to the key user extensibility framework and delete the original code.

The other types of legacy code are not recommended to be eliminated, as they may still be relevant or necessary for your business processes. However, you should still review and adjust them according to the SAP S/4HANA simplification items and best practices. These types of code are:

Code that supports a critical business process. This type of code is essential for your business operations and cannot be easily replaced or removed. However, you should check if this type of code is compatible with SAP S/4HANA, and if not, you should adapt it accordingly. You should also consider if this type of code can be optimized or enhanced using the new features and capabilities of SAP S/4HANA.

Code that has less than 10% usage according to usage statistics. This type of code is rarely used and may not be worth maintaining or converting. However, you should not delete this type of code without verifying its relevance and impact on your business processes. You should also consider if this type of code can be replaced or consolidated with other code that has higher usage or better performance.

References: Custom Code Management (CCM) During an SAP S/4HANA Conversion, Custom Code Migration Guide for SAP S/4HANA 2020

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 annotation @Environment.systemField: #LANGUAGE is used to assign the ABAP system field sy-langu to an input parameter of a CDS view or a CDS table function. This enables the implicit parameter passing in Open SQL, which means that the value of sy-langu will be automatically passed to the CDS view without explicitly specifying it in the WHERE clause. This also applies to the CDS views that use the annotated CDS view as a data source, which means that the value of sy-langu will be propagated to the nested CDS views (view on view)12. For example:

The following code snippet defines a CDS view ZI_FLIGHT_TEXTS with an input parameter p_langu that is annotated with @Environment.systemField: #LANGUAGE:

define view ZI_FLIGHT_TEXTS with parameters p_langu : syst_langu @

The following code snippet shows how to use the CDS view ZI_FLIGHT_TEXTS in ABAP without specifying the value of p_langu in the WHERE clause. The value of sy-langu will be automatically passed to the CDS view:

SELECT carrid, connid, fldate, carrname, carrtext FROM zi_flight_texts INTO TABLE @DATA(lt_flights).

The following code snippet shows how to use the CDS view ZI_FLIGHT_TEXTS in another CDS view ZI_FLIGHT_REPORT. The value of sy-langu will be automatically passed to the nested CDS view ZI_FLIGHT_TEXTS:

define view ZI_FLIGHT_REPORT with parameters p_langu : syst_langu @

The annotation @Environment.systemField: #LANGUAGE does not prevent the possibility of overriding the default value with a value of your own. You can still specify a different value for the input parameter p_langu in the WHERE clause, either in ABAP or in another CDS view. This will override the value of sy-langu and pass the specified value to the CDS view12. For example:

The following code snippet shows how to use the CDS view ZI_FLIGHT_TEXTS in ABAP with a specified value of p_langu in the WHERE clause. The value ‘E’ will be passed to the CDS view instead of the value of sy-langu:

SELECT carrid, connid, fldate, carrname, carrtext FROM zi_flight_texts WHERE p_langu = ‘E’ INTO TABLE @DATA(lt_flights).

The following code snippet shows how to use the CDS view ZI_FLIGHT_TEXTS in another CDS view ZI_FLIGHT_REPORT with a specified value of p_langu in the WHERE clause. The value ‘E’ will be passed to the nested CDS view ZI_FLIGHT_TEXTS instead of the value of sy-langu:

define view ZI_FLIGHT_REPORT with parameters p_langu : syst_langu @

References: 1: ABAP CDS - parameter_annot - ABAP Keyword Documentation - SAP Online Help 2: ABAP CDS - session_variable - ABAP Keyword Documentation - SAP Online Help