ABAP Select data from SAP table VWAHN into internal table

Get Example source ABAP code based on a different SAP table
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Below is a number of ABAP code snippets to demonstrate how to select data from SAP VWAHN 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 VWAHN. 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 VWAHN 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_VWAHN TYPE STANDARD TABLE OF VWAHN,
      WA_VWAHN TYPE VWAHN,
      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: <VWAHN> TYPE VWAHN.

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

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

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM VWAHN
*  INTO TABLE @DATA(IT_VWAHN2).
*--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_VWAHN INDEX 1 INTO DATA(WA_VWAHN2).


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

*To update a field value using a field symbol simply change the value via the field symbol pointer
<VWAHN>-EXIDV = 1.
<VWAHN>-EXIDE = 1.
<VWAHN>-VHILM = 1.
<VWAHN>-VHMKU = 1.
<VWAHN>-NTGEW = 1.

ENDLOOP.

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

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_VWAHN-BRGEW, sy-vline,
  WA_VWAHN-GEWEI, sy-vline,
  WA_VWAHN-SMGKN, sy-vline,
  WA_VWAHN-VEMNG, sy-vline,
  WA_VWAHN-VEMEH, sy-vline,
  WA_VWAHN-MATNR, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_VWAHN 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_VWAHN 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_VWAHN INTO WA_VWAHN.


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

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

*Conversion exit MATN1, internal->external for field VHILM
CALL FUNCTION 'CONVERSION_EXIT_MATN1_OUTPUT'
  EXPORTING
    input =                      WA_VWAHN-VHILM
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_VWAHN-VHILM.
WRITE:/ 'New Value:', ld_input.

*Conversion exit CUNIT, internal->external for field GEWEI
CALL FUNCTION 'CONVERSION_EXIT_CUNIT_OUTPUT'
  EXPORTING
    input =                      WA_VWAHN-GEWEI
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_VWAHN-GEWEI.
WRITE:/ 'New Value:', ld_input.

*Conversion exit CUNIT, internal->external for field VEMEH
CALL FUNCTION 'CONVERSION_EXIT_CUNIT_OUTPUT'
  EXPORTING
    input =                      WA_VWAHN-VEMEH
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_VWAHN-VEMEH.
WRITE:/ 'New Value:', ld_input.

*Conversion exit MATN1, internal->external for field MATNR
CALL FUNCTION 'CONVERSION_EXIT_MATN1_OUTPUT'
  EXPORTING
    input =                      WA_VWAHN-MATNR
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_VWAHN-MATNR.
WRITE:/ 'New Value:', ld_input.

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

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

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

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

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

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

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

*Conversion exit CUNIT, internal->external for field /CWM/VEMEH
CALL FUNCTION 'CONVERSION_EXIT_CUNIT_OUTPUT'
  EXPORTING
    input =                      WA_VWAHN-/CWM/VEMEH
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_VWAHN-/CWM/VEMEH.
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_VWAHN_STR, 
EXIDV TYPE STRING,
EXIDE TYPE STRING,
VHILM TYPE STRING,
VHMKU TYPE STRING,
NTGEW TYPE STRING,
BRGEW TYPE STRING,
GEWEI TYPE STRING,
SMGKN TYPE STRING,
VEMNG TYPE STRING,
VEMEH TYPE STRING,
MATNR TYPE STRING,
KDMAT TYPE STRING,
CHARG TYPE STRING,
AESKD TYPE STRING,
ARKTX TYPE STRING,
KUNNR TYPE STRING,
KUADR TYPE STRING,
KULAN TYPE STRING,
ABLAD TYPE STRING,
VBRST TYPE STRING,
EIKTO TYPE STRING,
VSTEL TYPE STRING,
VSADR TYPE STRING,
VBELN TYPE STRING,
LIFEX TYPE STRING,
TKNUM TYPE STRING,
ANZPK TYPE STRING,
WADAT TYPE STRING,
AUFNR TYPE STRING,
VEGR1 TYPE STRING,
VEGR2 TYPE STRING,
VEGR3 TYPE STRING,
VEGR4 TYPE STRING,
VEGR5 TYPE STRING,
ADDR_TYPE TYPE STRING,
ADRNP TYPE STRING,
/CWM/VEMNG TYPE STRING,
/CWM/VEMEH TYPE STRING,END OF T_EKKO_STR.
DATA: WA_VWAHN_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_VWAHN_STR-EXIDV sy-vline 
WA_VWAHN_STR-EXIDE sy-vline 
WA_VWAHN_STR-VHILM sy-vline 
WA_VWAHN_STR-VHMKU sy-vline 
WA_VWAHN_STR-NTGEW sy-vline 
WA_VWAHN_STR-BRGEW sy-vline 
WA_VWAHN_STR-GEWEI sy-vline 
WA_VWAHN_STR-SMGKN sy-vline 
WA_VWAHN_STR-VEMNG sy-vline 
WA_VWAHN_STR-VEMEH sy-vline 
WA_VWAHN_STR-MATNR sy-vline 
WA_VWAHN_STR-KDMAT sy-vline 
WA_VWAHN_STR-CHARG sy-vline 
WA_VWAHN_STR-AESKD sy-vline 
WA_VWAHN_STR-ARKTX sy-vline 
WA_VWAHN_STR-KUNNR sy-vline 
WA_VWAHN_STR-KUADR sy-vline 
WA_VWAHN_STR-KULAN sy-vline 
WA_VWAHN_STR-ABLAD sy-vline 
WA_VWAHN_STR-VBRST sy-vline 
WA_VWAHN_STR-EIKTO sy-vline 
WA_VWAHN_STR-VSTEL sy-vline 
WA_VWAHN_STR-VSADR sy-vline 
WA_VWAHN_STR-VBELN sy-vline 
WA_VWAHN_STR-LIFEX sy-vline 
WA_VWAHN_STR-TKNUM sy-vline 
WA_VWAHN_STR-ANZPK sy-vline 
WA_VWAHN_STR-WADAT sy-vline 
WA_VWAHN_STR-AUFNR sy-vline 
WA_VWAHN_STR-VEGR1 sy-vline 
WA_VWAHN_STR-VEGR2 sy-vline 
WA_VWAHN_STR-VEGR3 sy-vline 
WA_VWAHN_STR-VEGR4 sy-vline 
WA_VWAHN_STR-VEGR5 sy-vline 
WA_VWAHN_STR-ADDR_TYPE sy-vline 
WA_VWAHN_STR-ADRNP sy-vline 
WA_VWAHN_STR-/CWM/VEMNG sy-vline 
WA_VWAHN_STR-/CWM/VEMEH sy-vline      INTO ld_text SEPARATED BY SPACE.

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