CLASS zcl_itab_nesting DEFINITION
  PUBLIC
  FINAL
  CREATE PUBLIC .

  PUBLIC SECTION.

    TYPES: BEGIN OF artists_type,
             artist_id   TYPE string,
             artist_name TYPE string,
           END OF artists_type.
    TYPES artists TYPE STANDARD TABLE OF artists_type WITH KEY artist_id.
    TYPES: BEGIN OF albums_type,
             artist_id  TYPE string,
             album_id   TYPE string,
             album_name TYPE string,
           END OF albums_type.
    TYPES albums TYPE STANDARD TABLE OF albums_type WITH KEY artist_id album_id.
    TYPES: BEGIN OF songs_type,
             artist_id TYPE string,
             album_id  TYPE string,
             song_id   TYPE string,
             song_name TYPE string,
           END OF songs_type.
    TYPES songs TYPE STANDARD TABLE OF songs_type WITH KEY artist_id album_id song_id.


    TYPES: BEGIN OF song_nested_type,
             song_id   TYPE string,
             song_name TYPE string,
           END OF song_nested_type.
    TYPES: BEGIN OF album_song_nested_type,
             album_id   TYPE string,
             album_name TYPE string,
             songs      TYPE STANDARD TABLE OF song_nested_type WITH KEY song_id,
           END OF album_song_nested_type.
    TYPES: BEGIN OF artist_album_nested_type,
             artist_id   TYPE string,
             artist_name TYPE string,
             albums      TYPE STANDARD TABLE OF album_song_nested_type WITH KEY album_id,
           END OF artist_album_nested_type.
    TYPES nested_data TYPE STANDARD TABLE OF artist_album_nested_type WITH KEY artist_id.

    METHODS perform_nesting
      IMPORTING
        artists            TYPE artists
        albums             TYPE albums
        songs              TYPE songs
      RETURNING
        VALUE(nested_data) TYPE nested_data.

  PROTECTED SECTION.
  PRIVATE SECTION.
ENDCLASS.

CLASS zcl_itab_nesting IMPLEMENTATION.

  METHOD perform_nesting.

    nested_data = VALUE #(
        FOR artist_iterator IN artists ( artist_id = artist_iterator-artist_id artist_name = artist_iterator-artist_name
            albums = VALUE #( FOR album_iterator IN albums
                     WHERE ( artist_id = artist_iterator-artist_id )
                           ( album_id = album_iterator-album_id album_name = album_iterator-album_name
            songs  = VALUE #( FOR song_iterator IN songs
                     WHERE ( artist_id = artist_iterator-artist_id AND album_id = album_iterator-album_id )
                           ( song_id = song_iterator-song_id song_name = song_iterator-song_name ) )
             ) ) ) ).

  ENDMETHOD.

ENDCLASS.