ABAP Select data from SAP table RCGAPICLASS into internal table

Get Example source ABAP code based on a different SAP table
  Get ABAP code

Below is a number of ABAP code snippets to demonstrate how to select data from SAP RCGAPICLASS table and store it within an internal table, including using the newer @DATA inline declaration methods. It also shows you various ways to process this data using ABAP work area, inline declaration or field symbols including executing all the relevant CONVERSION_EXIT routines specific to RCGAPICLASS. See here for more generic Select statement tips.

Sometimes data within SAP is stored within the database table in a different format to what it is displayed to the user. These input/output conversation FM routines are what translates the data between the two formats.

There is also a full declaration of the RCGAPICLASS table where each field has a char/string type for you to simply copy and paste. This allows you to use processing that is only available to these field types such as the CONCATENATE statement.

DATA: IT_RCGAPICLASS TYPE STANDARD TABLE OF RCGAPICLASS,
      WA_RCGAPICLASS TYPE RCGAPICLASS,
      GD_STR TYPE STRING.

DATA: lo_typedescr type REF TO cl_abap_typedescr.
DATA: lv_fieldname type fieldname.

FIELD-SYMBOLS: <FIELD> TYPE any.
FIELD-SYMBOLS: <RCGAPICLASS> TYPE RCGAPICLASS.

*Process all fields in table header/work area as string values
  PERFORM process_as_string_field_values CHANGING wa_RCGAPICLASS.

SELECT *
*restrict ABAP select to first 10 rows
 UP TO 10 ROWS      
  FROM RCGAPICLASS
  INTO TABLE IT_RCGAPICLASS.

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM RCGAPICLASS
*  INTO TABLE @DATA(IT_RCGAPICLASS2).
*--Further methods of using ABAP code to  select data from SAP database tables

*You can also declare the header/work area using the in-line DATA declaration method
READ TABLE IT_RCGAPICLASS INDEX 1 INTO DATA(WA_RCGAPICLASS2).


*Demonstrate how to loop at an internal table and update values using a FIELD-SYMBOL
LOOP AT IT_RCGAPICLASS ASSIGNING <RCGAPICLASS>.

*To update a field value using a field symbol simply change the value via the field symbol pointer
<RCGAPICLASS>-DMSDOKAR = 1.
<RCGAPICLASS>-DOKAR = 1.
<RCGAPICLASS>-DOKNR = 1.
<RCGAPICLASS>-DOKVR = 1.
<RCGAPICLASS>-DOKTL = 1.

ENDLOOP.

LOOP AT IT_RCGAPICLASS INTO WA_RCGAPICLASS.
*Write horizonal line to screen report.
  WRITE:/ sy-uline.

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_RCGAPICLASS-CLASSTYPE, sy-vline,
  WA_RCGAPICLASS-CLASSNAME, sy-vline,
  WA_RCGAPICLASS-STATUS, sy-vline,
  WA_RCGAPICLASS-STANDARDCLASS, sy-vline,
  WA_RCGAPICLASS-DELETEALLOCATION, sy-vline,
  WA_RCGAPICLASS-ECNUMBER, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_RCGAPICLASS you want to display...

  WRITE:/ sy-uline.
* Aternatively use generic code to Write field values (and NAME) to screen report
  DO.
    ASSIGN COMPONENT sy-index OF STRUCTURE wa_RCGAPICLASS TO <field>.
    IF sy-subrc <> 0. EXIT. ENDIF.
    WRITE:/ 'Field Value', <field>, sy-vline.
    gd_str = <field> .
    lo_typedescr ?= CL_ABAP_DATADESCR=>DESCRIBE_BY_DATA( <field> ).
    lv_fieldname = lo_typedescr->GET_RELATIVE_NAME( ).
    WRITE:/ 'Field Name', lv_fieldname.
  ENDDO.

  
*Redo loop but convert all fields from internal to out value  
LOOP AT IT_RCGAPICLASS INTO WA_RCGAPICLASS.


*Write horizonal line to screen report.
  WRITE:/ sy-uline.

*Convert all fields to display/output versions using conversion routines
  PERFORM convert_all_field_values CHANGING wa_EKKO.
	 
ENDLOOP.

  
*&---------------------------------------------------------------------*
*& Form convert_all_field_values
*&---------------------------------------------------------------------*
FORM convert_all_field_values CHANGING p_EKKO LIKE wa_EKKO.
DATA: ld_input(1000) TYPE c, ld_output(1000) TYPE C.

*Conversion exit ALPHA, internal->external for field DOKNR
CALL FUNCTION 'CONVERSION_EXIT_ALPHA_OUTPUT'
  EXPORTING
    input =                      WA_RCGAPICLASS-DOKNR
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_RCGAPICLASS-DOKNR.
WRITE:/ 'New Value:', ld_input.

*Conversion exit ALPHA, internal->external for field ECNUMBER
CALL FUNCTION 'CONVERSION_EXIT_ALPHA_OUTPUT'
  EXPORTING
    input =                      WA_RCGAPICLASS-ECNUMBER
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_RCGAPICLASS-ECNUMBER.
WRITE:/ 'New Value:', ld_input.
ENDFORM. 

*&---------------------------------------------------------------------*
*& Form process_as_string_field_values
*&---------------------------------------------------------------------*
FORM process_as_string_field_values CHANGING p_EKKO LIKE wa_EKKO.

TYPES: BEGIN OF T_RCGAPICLASS_STR, 
DMSDOKAR TYPE STRING,
DOKAR TYPE STRING,
DOKNR TYPE STRING,
DOKVR TYPE STRING,
DOKTL TYPE STRING,
CLASSTYPE TYPE STRING,
CLASSNAME TYPE STRING,
STATUS TYPE STRING,
STANDARDCLASS TYPE STRING,
DELETEALLOCATION TYPE STRING,
ECNUMBER TYPE STRING,
ERRORMODE TYPE STRING,
ERRORINFO TYPE STRING,
ERRORCLASS TYPE STRING,
ERRORPARAM TYPE STRING,
LOGLOCKMOD TYPE STRING,
EXTINFO TYPE STRING,
LINEMOD TYPE STRING,END OF T_EKKO_STR.
DATA: WA_RCGAPICLASS_STR type T_EKKO_STR.

DATA: ld_text TYPE string.

LOOP AT IT_EKKO INTO WA_EKKO.
  MOVE-CORRESPONDING wa_EKKO TO WA_EKKO_STR.
  CONCATENATE: sy-vline
WA_RCGAPICLASS_STR-DMSDOKAR sy-vline 
WA_RCGAPICLASS_STR-DOKAR sy-vline 
WA_RCGAPICLASS_STR-DOKNR sy-vline 
WA_RCGAPICLASS_STR-DOKVR sy-vline 
WA_RCGAPICLASS_STR-DOKTL sy-vline 
WA_RCGAPICLASS_STR-CLASSTYPE sy-vline 
WA_RCGAPICLASS_STR-CLASSNAME sy-vline 
WA_RCGAPICLASS_STR-STATUS sy-vline 
WA_RCGAPICLASS_STR-STANDARDCLASS sy-vline 
WA_RCGAPICLASS_STR-DELETEALLOCATION sy-vline 
WA_RCGAPICLASS_STR-ECNUMBER sy-vline 
WA_RCGAPICLASS_STR-ERRORMODE sy-vline 
WA_RCGAPICLASS_STR-ERRORINFO sy-vline 
WA_RCGAPICLASS_STR-ERRORCLASS sy-vline 
WA_RCGAPICLASS_STR-ERRORPARAM sy-vline 
WA_RCGAPICLASS_STR-LOGLOCKMOD sy-vline 
WA_RCGAPICLASS_STR-EXTINFO sy-vline 
WA_RCGAPICLASS_STR-LINEMOD sy-vline      INTO ld_text SEPARATED BY SPACE.

*Add any further fields from structure WA_EKKO_STR you want to CONCATENATE...
ENDLOOP.
ENDFORM.