ABAP Select data from SAP table PSG8A 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 PSG8A 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 PSG8A. 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 PSG8A 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_PSG8A TYPE STANDARD TABLE OF PSG8A,
      WA_PSG8A TYPE PSG8A,
      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: <PSG8A> TYPE PSG8A.

*Process all fields in table header/work area as string values
  PERFORM process_as_string_field_values CHANGING wa_PSG8A.

SELECT *
*restrict ABAP select to first 10 rows
 UP TO 10 ROWS      
  FROM PSG8A
  INTO TABLE IT_PSG8A.

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM PSG8A
*  INTO TABLE @DATA(IT_PSG8A2).
*--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_PSG8A INDEX 1 INTO DATA(WA_PSG8A2).


*Demonstrate how to loop at an internal table and update values using a FIELD-SYMBOL
LOOP AT IT_PSG8A ASSIGNING <PSG8A>.

*To update a field value using a field symbol simply change the value via the field symbol pointer
<PSG8A>-COMPNO = 1.
<PSG8A>-COMPC = 1.
<PSG8A>-COMPT = 1.
<PSG8A>-FORMULAE = 1.
<PSG8A>-COMPV = 1.

ENDLOOP.

LOOP AT IT_PSG8A INTO WA_PSG8A.
*Write horizonal line to screen report.
  WRITE:/ sy-uline.

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_PSG8A-OTYPE, sy-vline,
  WA_PSG8A-HEADER, sy-vline,
  WA_PSG8A-FOOTER1, sy-vline,
  WA_PSG8A-FOOTER2, sy-vline,
  WA_PSG8A-FOOTER3, sy-vline,
  WA_PSG8A-FOOTER4, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_PSG8A 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_PSG8A 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_PSG8A INTO WA_PSG8A.


*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_PSG8A_STR, 
COMPNO TYPE STRING,
COMPC TYPE STRING,
COMPT TYPE STRING,
FORMULAE TYPE STRING,
COMPV TYPE STRING,
OTYPE TYPE STRING,
HEADER TYPE STRING,
FOOTER1 TYPE STRING,
FOOTER2 TYPE STRING,
FOOTER3 TYPE STRING,
FOOTER4 TYPE STRING,
WAERS TYPE STRING,END OF T_EKKO_STR.
DATA: WA_PSG8A_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_PSG8A_STR-COMPNO sy-vline 
WA_PSG8A_STR-COMPC sy-vline 
WA_PSG8A_STR-COMPT sy-vline 
WA_PSG8A_STR-FORMULAE sy-vline 
WA_PSG8A_STR-COMPV sy-vline 
WA_PSG8A_STR-OTYPE sy-vline 
WA_PSG8A_STR-HEADER sy-vline 
WA_PSG8A_STR-FOOTER1 sy-vline 
WA_PSG8A_STR-FOOTER2 sy-vline 
WA_PSG8A_STR-FOOTER3 sy-vline 
WA_PSG8A_STR-FOOTER4 sy-vline 
WA_PSG8A_STR-WAERS sy-vline      INTO ld_text SEPARATED BY SPACE.

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