ABAP Select data from SAP table DIS20 into internal table

Get Example source ABAP code based on a different SAP table
  Get ABAP code

Below is a number of ABAP code snippets to demonstrate how to select data from SAP DIS20 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 DIS20. 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 DIS20 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_DIS20 TYPE STANDARD TABLE OF DIS20,
      WA_DIS20 TYPE DIS20,
      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: <DIS20> TYPE DIS20.

*Process all fields in table header/work area as string values
  PERFORM process_as_string_field_values CHANGING wa_DIS20.

SELECT *
*restrict ABAP select to first 10 rows
 UP TO 10 ROWS      
  FROM DIS20
  INTO TABLE IT_DIS20.

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM DIS20
*  INTO TABLE @DATA(IT_DIS202).
*--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_DIS20 INDEX 1 INTO DATA(WA_DIS202).


*Demonstrate how to loop at an internal table and update values using a FIELD-SYMBOL
LOOP AT IT_DIS20 ASSIGNING <DIS20>.

*To update a field value using a field symbol simply change the value via the field symbol pointer
<DIS20>-MCONAME = 1.
<DIS20>-AS4LOCAL = 1.
<DIS20>-AS4VERS = 1.
<DIS20>-DDLANGUAGE = 1.
<DIS20>-APPLCLASS = 1.

ENDLOOP.

LOOP AT IT_DIS20 INTO WA_DIS20.
*Write horizonal line to screen report.
  WRITE:/ sy-uline.

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_DIS20-AUTHCLASS, sy-vline,
  WA_DIS20-VIEWNAME, sy-vline,
  WA_DIS20-ROOTTAB, sy-vline,
  WA_DIS20-POOL, sy-vline,
  WA_DIS20-AS4USER, sy-vline,
  WA_DIS20-AS4DATE, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_DIS20 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_DIS20 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_DIS20 INTO WA_DIS20.


*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_DIS20_STR, 
MCONAME TYPE STRING,
AS4LOCAL TYPE STRING,
AS4VERS TYPE STRING,
DDLANGUAGE TYPE STRING,
APPLCLASS TYPE STRING,
AUTHCLASS TYPE STRING,
VIEWNAME TYPE STRING,
ROOTTAB TYPE STRING,
POOL TYPE STRING,
AS4USER TYPE STRING,
AS4DATE TYPE STRING,
AS4TIME TYPE STRING,
MCTEXT TYPE STRING,END OF T_EKKO_STR.
DATA: WA_DIS20_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_DIS20_STR-MCONAME sy-vline 
WA_DIS20_STR-AS4LOCAL sy-vline 
WA_DIS20_STR-AS4VERS sy-vline 
WA_DIS20_STR-DDLANGUAGE sy-vline 
WA_DIS20_STR-APPLCLASS sy-vline 
WA_DIS20_STR-AUTHCLASS sy-vline 
WA_DIS20_STR-VIEWNAME sy-vline 
WA_DIS20_STR-ROOTTAB sy-vline 
WA_DIS20_STR-POOL sy-vline 
WA_DIS20_STR-AS4USER sy-vline 
WA_DIS20_STR-AS4DATE sy-vline 
WA_DIS20_STR-AS4TIME sy-vline 
WA_DIS20_STR-MCTEXT sy-vline      INTO ld_text SEPARATED BY SPACE.

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