ABAP Select data from SAP table VIAK18 into internal table

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Below is a number of ABAP code snippets to demonstrate how to select data from SAP VIAK18 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 VIAK18. 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 VIAK18 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_VIAK18 TYPE STANDARD TABLE OF VIAK18,
      WA_VIAK18 TYPE VIAK18,
      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: <VIAK18> TYPE VIAK18.

*Process all fields in table header/work area as string values
  PERFORM process_as_string_field_values CHANGING wa_VIAK18.

SELECT *
*restrict ABAP select to first 10 rows
 UP TO 10 ROWS      
  FROM VIAK18
  INTO TABLE IT_VIAK18.

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM VIAK18
*  INTO TABLE @DATA(IT_VIAK182).
*--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_VIAK18 INDEX 1 INTO DATA(WA_VIAK182).


*Demonstrate how to loop at an internal table and update values using a FIELD-SYMBOL
LOOP AT IT_VIAK18 ASSIGNING <VIAK18>.

*To update a field value using a field symbol simply change the value via the field symbol pointer
<VIAK18>-MANDT = 1.
<VIAK18>-VVABBLN = 1.
<VIAK18>-BUKRS = 1.
<VIAK18>-SMIVE = 1.
<VIAK18>-SWENR = 1.

ENDLOOP.

LOOP AT IT_VIAK18 INTO WA_VIAK18.
*Write horizonal line to screen report.
  WRITE:/ sy-uline.

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_VIAK18-SMENR, sy-vline,
  WA_VIAK18-BVERWHON, sy-vline,
  WA_VIAK18-BMWST, sy-vline,
  WA_VIAK18-MWSKZ, sy-vline,
  WA_VIAK18-TXJCD, sy-vline,
  WA_VIAK18-PROZENTSATZ, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_VIAK18 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_VIAK18 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_VIAK18 INTO WA_VIAK18.


*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 SMIVE
CALL FUNCTION 'CONVERSION_EXIT_ALPHA_OUTPUT'
  EXPORTING
    input =                      WA_VIAK18-SMIVE
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_VIAK18-SMIVE.
WRITE:/ 'New Value:', ld_input.

*Conversion exit SWENR, internal->external for field SWENR
CALL FUNCTION 'CONVERSION_EXIT_SWENR_OUTPUT'
  EXPORTING
    input =                      WA_VIAK18-SWENR
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_VIAK18-SWENR.
WRITE:/ 'New Value:', ld_input.

*Conversion exit SMENR, internal->external for field SMENR
CALL FUNCTION 'CONVERSION_EXIT_SMENR_OUTPUT'
  EXPORTING
    input =                      WA_VIAK18-SMENR
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_VIAK18-SMENR.
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_VIAK18_STR, 
MANDT TYPE STRING,
VVABBLN TYPE STRING,
BUKRS TYPE STRING,
SMIVE TYPE STRING,
SWENR TYPE STRING,
SMENR TYPE STRING,
BVERWHON TYPE STRING,
BMWST TYPE STRING,
MWSKZ TYPE STRING,
TXJCD TYPE STRING,
PROZENTSATZ TYPE STRING,
JEXTRACHARGE TYPE STRING,
DVONPER TYPE STRING,
DBISPER TYPE STRING,END OF T_EKKO_STR.
DATA: WA_VIAK18_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_VIAK18_STR-MANDT sy-vline 
WA_VIAK18_STR-VVABBLN sy-vline 
WA_VIAK18_STR-BUKRS sy-vline 
WA_VIAK18_STR-SMIVE sy-vline 
WA_VIAK18_STR-SWENR sy-vline 
WA_VIAK18_STR-SMENR sy-vline 
WA_VIAK18_STR-BVERWHON sy-vline 
WA_VIAK18_STR-BMWST sy-vline 
WA_VIAK18_STR-MWSKZ sy-vline 
WA_VIAK18_STR-TXJCD sy-vline 
WA_VIAK18_STR-PROZENTSATZ sy-vline 
WA_VIAK18_STR-JEXTRACHARGE sy-vline 
WA_VIAK18_STR-DVONPER sy-vline 
WA_VIAK18_STR-DBISPER sy-vline      INTO ld_text SEPARATED BY SPACE.

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