ABAP Select data from SAP table V_TWWKA into internal table

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

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

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

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM V_TWWKA
*  INTO TABLE @DATA(IT_V_TWWKA2).
*--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_V_TWWKA INDEX 1 INTO DATA(WA_V_TWWKA2).


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

*To update a field value using a field symbol simply change the value via the field symbol pointer
<V_TWWKA>-MANDT = 1.
<V_TWWKA>-WKART = 1.
<V_TWWKA>-WKATX = 1.
<V_TWWKA>-EKERV = 1.
<V_TWWKA>-VKERV = 1.

ENDLOOP.

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

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_V_TWWKA-WWAER, sy-vline,
  WA_V_TWWKA-WAUFR, sy-vline,
  WA_V_TWWKA-KURST, sy-vline,
  WA_V_TWWKA-VKLIG, sy-vline,
  WA_V_TWWKA-VKLIV, sy-vline,
  WA_V_TWWKA-NUMKI, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_V_TWWKA 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_V_TWWKA 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_V_TWWKA INTO WA_V_TWWKA.


*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.
ENDFORM. 

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

TYPES: BEGIN OF T_V_TWWKA_STR, 
MANDT TYPE STRING,
WKART TYPE STRING,
WKATX TYPE STRING,
EKERV TYPE STRING,
VKERV TYPE STRING,
WWAER TYPE STRING,
WAUFR TYPE STRING,
KURST TYPE STRING,
VKLIG TYPE STRING,
VKLIV TYPE STRING,
NUMKI TYPE STRING,
NUMKE TYPE STRING,
LTEXT TYPE STRING,
CURVW TYPE STRING,
LITXT TYPE STRING,
SVARI TYPE STRING,
PERNU TYPE STRING,
AFNAM TYPE STRING,END OF T_EKKO_STR.
DATA: WA_V_TWWKA_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_V_TWWKA_STR-MANDT sy-vline 
WA_V_TWWKA_STR-WKART sy-vline 
WA_V_TWWKA_STR-WKATX sy-vline 
WA_V_TWWKA_STR-EKERV sy-vline 
WA_V_TWWKA_STR-VKERV sy-vline 
WA_V_TWWKA_STR-WWAER sy-vline 
WA_V_TWWKA_STR-WAUFR sy-vline 
WA_V_TWWKA_STR-KURST sy-vline 
WA_V_TWWKA_STR-VKLIG sy-vline 
WA_V_TWWKA_STR-VKLIV sy-vline 
WA_V_TWWKA_STR-NUMKI sy-vline 
WA_V_TWWKA_STR-NUMKE sy-vline 
WA_V_TWWKA_STR-LTEXT sy-vline 
WA_V_TWWKA_STR-CURVW sy-vline 
WA_V_TWWKA_STR-LITXT sy-vline 
WA_V_TWWKA_STR-SVARI sy-vline 
WA_V_TWWKA_STR-PERNU sy-vline 
WA_V_TWWKA_STR-AFNAM sy-vline      INTO ld_text SEPARATED BY SPACE.

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