ABAP Select data from SAP table KNVA into internal table

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

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

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

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM KNVA
*  INTO TABLE @DATA(IT_KNVA2).
*--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_KNVA INDEX 1 INTO DATA(WA_KNVA2).


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

*To update a field value using a field symbol simply change the value via the field symbol pointer
<KNVA>-MANDT = 1.
<KNVA>-KUNNR = 1.
<KNVA>-ABLAD = 1.
<KNVA>-LFDNR = 1.
<KNVA>-KNFAK = 1.

ENDLOOP.

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

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_KNVA-WANID, sy-vline,
  WA_KNVA-TPQUA, sy-vline,
  WA_KNVA-TPGRP, sy-vline,
  WA_KNVA-STZKL, sy-vline,
  WA_KNVA-STZZU, sy-vline,
  WA_KNVA-MOAB1, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_KNVA 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_KNVA 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_KNVA INTO WA_KNVA.


*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 KUNNR
CALL FUNCTION 'CONVERSION_EXIT_ALPHA_OUTPUT'
  EXPORTING
    input =                      WA_KNVA-KUNNR
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_KNVA-KUNNR.
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_KNVA_STR, 
MANDT TYPE STRING,
KUNNR TYPE STRING,
ABLAD TYPE STRING,
LFDNR TYPE STRING,
KNFAK TYPE STRING,
WANID TYPE STRING,
TPQUA TYPE STRING,
TPGRP TYPE STRING,
STZKL TYPE STRING,
STZZU TYPE STRING,
MOAB1 TYPE STRING,
MOBI1 TYPE STRING,
MOAB2 TYPE STRING,
MOBI2 TYPE STRING,
DIAB1 TYPE STRING,
DIBI1 TYPE STRING,
DIAB2 TYPE STRING,
DIBI2 TYPE STRING,
MIAB1 TYPE STRING,
MIBI1 TYPE STRING,
MIAB2 TYPE STRING,
MIBI2 TYPE STRING,
DOAB1 TYPE STRING,
DOBI1 TYPE STRING,
DOAB2 TYPE STRING,
DOBI2 TYPE STRING,
FRAB1 TYPE STRING,
FRBI1 TYPE STRING,
FRAB2 TYPE STRING,
FRBI2 TYPE STRING,
SAAB1 TYPE STRING,
SABI1 TYPE STRING,
SAAB2 TYPE STRING,
SABI2 TYPE STRING,
SOAB1 TYPE STRING,
SOBI1 TYPE STRING,
SOAB2 TYPE STRING,
SOBI2 TYPE STRING,
DEFAB TYPE STRING,END OF T_EKKO_STR.
DATA: WA_KNVA_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_KNVA_STR-MANDT sy-vline 
WA_KNVA_STR-KUNNR sy-vline 
WA_KNVA_STR-ABLAD sy-vline 
WA_KNVA_STR-LFDNR sy-vline 
WA_KNVA_STR-KNFAK sy-vline 
WA_KNVA_STR-WANID sy-vline 
WA_KNVA_STR-TPQUA sy-vline 
WA_KNVA_STR-TPGRP sy-vline 
WA_KNVA_STR-STZKL sy-vline 
WA_KNVA_STR-STZZU sy-vline 
WA_KNVA_STR-MOAB1 sy-vline 
WA_KNVA_STR-MOBI1 sy-vline 
WA_KNVA_STR-MOAB2 sy-vline 
WA_KNVA_STR-MOBI2 sy-vline 
WA_KNVA_STR-DIAB1 sy-vline 
WA_KNVA_STR-DIBI1 sy-vline 
WA_KNVA_STR-DIAB2 sy-vline 
WA_KNVA_STR-DIBI2 sy-vline 
WA_KNVA_STR-MIAB1 sy-vline 
WA_KNVA_STR-MIBI1 sy-vline 
WA_KNVA_STR-MIAB2 sy-vline 
WA_KNVA_STR-MIBI2 sy-vline 
WA_KNVA_STR-DOAB1 sy-vline 
WA_KNVA_STR-DOBI1 sy-vline 
WA_KNVA_STR-DOAB2 sy-vline 
WA_KNVA_STR-DOBI2 sy-vline 
WA_KNVA_STR-FRAB1 sy-vline 
WA_KNVA_STR-FRBI1 sy-vline 
WA_KNVA_STR-FRAB2 sy-vline 
WA_KNVA_STR-FRBI2 sy-vline 
WA_KNVA_STR-SAAB1 sy-vline 
WA_KNVA_STR-SABI1 sy-vline 
WA_KNVA_STR-SAAB2 sy-vline 
WA_KNVA_STR-SABI2 sy-vline 
WA_KNVA_STR-SOAB1 sy-vline 
WA_KNVA_STR-SOBI1 sy-vline 
WA_KNVA_STR-SOAB2 sy-vline 
WA_KNVA_STR-SOBI2 sy-vline 
WA_KNVA_STR-DEFAB sy-vline      INTO ld_text SEPARATED BY SPACE.

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