ABAP Select data from SAP table RNAT2 into internal table

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Below is a number of ABAP code snippets to demonstrate how to select data from SAP RNAT2 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 RNAT2. 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 RNAT2 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_RNAT2 TYPE STANDARD TABLE OF RNAT2,
      WA_RNAT2 TYPE RNAT2,
      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: <RNAT2> TYPE RNAT2.

*Process all fields in table header/work area as string values
  PERFORM process_as_string_field_values CHANGING wa_RNAT2.

SELECT *
*restrict ABAP select to first 10 rows
 UP TO 10 ROWS      
  FROM RNAT2
  INTO TABLE IT_RNAT2.

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM RNAT2
*  INTO TABLE @DATA(IT_RNAT22).
*--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_RNAT2 INDEX 1 INTO DATA(WA_RNAT22).


*Demonstrate how to loop at an internal table and update values using a FIELD-SYMBOL
LOOP AT IT_RNAT2 ASSIGNING <RNAT2>.

*To update a field value using a field symbol simply change the value via the field symbol pointer
<RNAT2>-BELNR = 1.
<RNAT2>-EINRI = 1.
<RNAT2>-FALNR = 1.
<RNAT2>-KOSTR = 1.
<RNAT2>-LFDNR = 1.

ENDLOOP.

LOOP AT IT_RNAT2 INTO WA_RNAT2.
*Write horizonal line to screen report.
  WRITE:/ sy-uline.

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_RNAT2-EZLRE, sy-vline,
  WA_RNAT2-VERLG, sy-vline,
  WA_RNAT2-BEZST, sy-vline,
  WA_RNAT2-KLASS, sy-vline,
  WA_RNAT2-KUBD1, sy-vline,
  WA_RNAT2-PROZ1, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_RNAT2 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_RNAT2 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_RNAT2 INTO WA_RNAT2.


*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 BELNR
CALL FUNCTION 'CONVERSION_EXIT_ALPHA_OUTPUT'
  EXPORTING
    input =                      WA_RNAT2-BELNR
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_RNAT2-BELNR.
WRITE:/ 'New Value:', ld_input.

*Conversion exit ALPHA, internal->external for field EINRI
CALL FUNCTION 'CONVERSION_EXIT_ALPHA_OUTPUT'
  EXPORTING
    input =                      WA_RNAT2-EINRI
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_RNAT2-EINRI.
WRITE:/ 'New Value:', ld_input.

*Conversion exit ALPHA, internal->external for field FALNR
CALL FUNCTION 'CONVERSION_EXIT_ALPHA_OUTPUT'
  EXPORTING
    input =                      WA_RNAT2-FALNR
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_RNAT2-FALNR.
WRITE:/ 'New Value:', ld_input.

*Conversion exit ALPHA, internal->external for field KOSTR
CALL FUNCTION 'CONVERSION_EXIT_ALPHA_OUTPUT'
  EXPORTING
    input =                      WA_RNAT2-KOSTR
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_RNAT2-KOSTR.
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_RNAT2_STR, 
BELNR TYPE STRING,
EINRI TYPE STRING,
FALNR TYPE STRING,
KOSTR TYPE STRING,
LFDNR TYPE STRING,
EZLRE TYPE STRING,
VERLG TYPE STRING,
BEZST TYPE STRING,
KLASS TYPE STRING,
KUBD1 TYPE STRING,
PROZ1 TYPE STRING,
KUBD2 TYPE STRING,
PROZ2 TYPE STRING,
KUBD3 TYPE STRING,
PROZ3 TYPE STRING,
KUEDT TYPE STRING,
FRIST TYPE STRING,
ABLGR TYPE STRING,
KBFRE TYPE STRING,
VPTKB TYPE STRING,
VPTBT TYPE STRING,
KRZUS TYPE STRING,
BSTAT TYPE STRING,
ERDAT TYPE STRING,
ERUSR TYPE STRING,
UPDAT TYPE STRING,
UPUSR TYPE STRING,
GEBKZ TYPE STRING,END OF T_EKKO_STR.
DATA: WA_RNAT2_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_RNAT2_STR-BELNR sy-vline 
WA_RNAT2_STR-EINRI sy-vline 
WA_RNAT2_STR-FALNR sy-vline 
WA_RNAT2_STR-KOSTR sy-vline 
WA_RNAT2_STR-LFDNR sy-vline 
WA_RNAT2_STR-EZLRE sy-vline 
WA_RNAT2_STR-VERLG sy-vline 
WA_RNAT2_STR-BEZST sy-vline 
WA_RNAT2_STR-KLASS sy-vline 
WA_RNAT2_STR-KUBD1 sy-vline 
WA_RNAT2_STR-PROZ1 sy-vline 
WA_RNAT2_STR-KUBD2 sy-vline 
WA_RNAT2_STR-PROZ2 sy-vline 
WA_RNAT2_STR-KUBD3 sy-vline 
WA_RNAT2_STR-PROZ3 sy-vline 
WA_RNAT2_STR-KUEDT sy-vline 
WA_RNAT2_STR-FRIST sy-vline 
WA_RNAT2_STR-ABLGR sy-vline 
WA_RNAT2_STR-KBFRE sy-vline 
WA_RNAT2_STR-VPTKB sy-vline 
WA_RNAT2_STR-VPTBT sy-vline 
WA_RNAT2_STR-KRZUS sy-vline 
WA_RNAT2_STR-BSTAT sy-vline 
WA_RNAT2_STR-ERDAT sy-vline 
WA_RNAT2_STR-ERUSR sy-vline 
WA_RNAT2_STR-UPDAT sy-vline 
WA_RNAT2_STR-UPUSR sy-vline 
WA_RNAT2_STR-GEBKZ sy-vline      INTO ld_text SEPARATED BY SPACE.

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