[ABAP] Schlüsselspalten einer DB-Tabelle ermitteln

SELECT FROM mara
  FIELDS *
  INTO TABLE @DATA(it_mara)
  UP TO 10 ROWS.

IF sy-subrc = 0.
* Table: Beschreibung
  DATA(o_tdesc) = CAST cl_abap_tabledescr( cl_abap_tabledescr=>describe_by_data( it_mara ) ).
* Row: Beschreibung
  DATA(o_sdesc) = CAST cl_abap_structdescr( o_tdesc->get_table_line_type( ) ).
* Key Fields
  DATA(it_keyflied_list) = o_sdesc->get_ddic_field_list( ).
* nur die Keyfields zurückgeben
  DELETE it_keyflied_list WHERE keyflag <> abap_true.

  cl_demo_output=>write_data( it_keyflied_list ).
  cl_demo_output=>write_data( it_mara ).

* HTML-Code vom Demo-Output holen
  DATA(lv_html) = cl_demo_output=>get( ).

* Daten im Inline-Browser im SAP-Fenster anzeigen
  cl_abap_browser=>show_html( EXPORTING title       = 'Key-Fields'
                                        html_string = lv_html
                                        container   = cl_gui_container=>default_screen ).

* cl_gui_container=>default_screen erzwingen
  WRITE: space.
ENDIF.