Complete C_ABAPD_2309 SAP Materials

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 predicate condition that can be used to ensure that the CAST will work is IS INSTANCE OF. The IS INSTANCE OF predicate condition checks whether the operand is an instance of the specified class or interface. This is useful when you want to perform a downcast, which is a conversion from a more general type to a more specific type. A downcast can fail if the operand is not an instance of the target type, and this can cause a runtime error. Therefore, you can use the IS INSTANCE OF predicate condition to check whether the downcast is possible before using the CAST operator12. For example:

• The following code snippet uses the IS INSTANCE OF predicate condition to check whether the variable g_super is an instance of the class lcl_super. If it is, the CAST will work and the variable g_sub1 will be assigned the value of g_super.

DATA: g_super TYPE REF TO lcl_super, g_sub1 TYPE REF TO lcl_sub1. IF g_super IS INSTANCE OF lcl_super. g_sub1 = CAST #( g_super ). g_sub1->method( … ). ENDIF.

You cannot do any of the following:

• IS SUPPLIED: The IS SUPPLIED predicate condition checks whether an optional parameter of a method or a function module has been supplied by the caller. This is useful when you want to handle different cases depending on whether the parameter has a value or not. However, this predicate condition has nothing to do with the CAST operator or the type of the operand12.
• IS NOT INITIAL: The IS NOT INITIAL predicate condition checks whether the operand has a non-initial value. This is useful when you want to check whether the operand has been assigned a value or not. However, this predicate condition does not guarantee that the CAST will work, because the operand may have a value but not be an instance of the target type12.
• IS BOUND: The IS BOUND predicate condition checks whether the operand is a bound reference variable. This is useful when you want to check whether the operand points to an existing object or not. However, this predicate condition does not guarantee that the CAST will work, because the operand may point to an object but not be an instance of the target type12.

References: 1: Predicate Expressions - ABAP Keyword Documentation - SAP Online Help 2: ABAP - Predicates | SAP Community

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

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