ABAP Select data from SAP table KNA1_REFERENCE into internal table

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Below is a number of ABAP code snippets to demonstrate how to select data from SAP KNA1_REFERENCE 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 KNA1_REFERENCE. 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 KNA1_REFERENCE 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_KNA1_REFERENCE TYPE STANDARD TABLE OF KNA1_REFERENCE,
      WA_KNA1_REFERENCE TYPE KNA1_REFERENCE,
      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: <KNA1_REFERENCE> TYPE KNA1_REFERENCE.

*Process all fields in table header/work area as string values
  PERFORM process_as_string_field_values CHANGING wa_KNA1_REFERENCE.

SELECT *
*restrict ABAP select to first 10 rows
 UP TO 10 ROWS      
  FROM KNA1_REFERENCE
  INTO TABLE IT_KNA1_REFERENCE.

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM KNA1_REFERENCE
*  INTO TABLE @DATA(IT_KNA1_REFERENCE2).
*--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_KNA1_REFERENCE INDEX 1 INTO DATA(WA_KNA1_REFERENCE2).


*Demonstrate how to loop at an internal table and update values using a FIELD-SYMBOL
LOOP AT IT_KNA1_REFERENCE ASSIGNING <KNA1_REFERENCE>.

*To update a field value using a field symbol simply change the value via the field symbol pointer
<KNA1_REFERENCE>-LAND1 = 1.
<KNA1_REFERENCE>-BEGRU = 1.
<KNA1_REFERENCE>-BRSCH = 1.
<KNA1_REFERENCE>-KONZS = 1.
<KNA1_REFERENCE>-SPRAS = 1.

ENDLOOP.

LOOP AT IT_KNA1_REFERENCE INTO WA_KNA1_REFERENCE.
*Write horizonal line to screen report.
  WRITE:/ sy-uline.

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_KNA1_REFERENCE-STKZA, sy-vline,
  WA_KNA1_REFERENCE-STKZU, sy-vline,
  WA_KNA1_REFERENCE-XZEMP, sy-vline,
  WA_KNA1_REFERENCE-STKZN, sy-vline,
  WA_KNA1_REFERENCE-KTOCD, sy-vline,
  WA_KNA1_REFERENCE-DTAMS, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_KNA1_REFERENCE 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_KNA1_REFERENCE 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_KNA1_REFERENCE INTO WA_KNA1_REFERENCE.


*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 ISOLA, internal->external for field SPRAS
CALL FUNCTION 'CONVERSION_EXIT_ISOLA_OUTPUT'
  EXPORTING
    input =                      WA_KNA1_REFERENCE-SPRAS
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_KNA1_REFERENCE-SPRAS.
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_KNA1_REFERENCE_STR, 
LAND1 TYPE STRING,
BEGRU TYPE STRING,
BRSCH TYPE STRING,
KONZS TYPE STRING,
SPRAS TYPE STRING,
STKZA TYPE STRING,
STKZU TYPE STRING,
XZEMP TYPE STRING,
STKZN TYPE STRING,
KTOCD TYPE STRING,
DTAMS TYPE STRING,
DTAWS TYPE STRING,
XKNZA TYPE STRING,END OF T_EKKO_STR.
DATA: WA_KNA1_REFERENCE_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_KNA1_REFERENCE_STR-LAND1 sy-vline 
WA_KNA1_REFERENCE_STR-BEGRU sy-vline 
WA_KNA1_REFERENCE_STR-BRSCH sy-vline 
WA_KNA1_REFERENCE_STR-KONZS sy-vline 
WA_KNA1_REFERENCE_STR-SPRAS sy-vline 
WA_KNA1_REFERENCE_STR-STKZA sy-vline 
WA_KNA1_REFERENCE_STR-STKZU sy-vline 
WA_KNA1_REFERENCE_STR-XZEMP sy-vline 
WA_KNA1_REFERENCE_STR-STKZN sy-vline 
WA_KNA1_REFERENCE_STR-KTOCD sy-vline 
WA_KNA1_REFERENCE_STR-DTAMS sy-vline 
WA_KNA1_REFERENCE_STR-DTAWS sy-vline 
WA_KNA1_REFERENCE_STR-XKNZA sy-vline      INTO ld_text SEPARATED BY SPACE.

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