Create AMDP Class Method & Implementation.

1. AMDP Architecture Overview.

CLASS zcl_amdp_demo DEFINITION
  PUBLIC
  FINAL
  CREATE PUBLIC.

  PUBLIC SECTION.

    INTERFACES: if_amdp_marker_hdb.

    TYPES: 
      BEGIN OF ty_mara,
        matnr TYPE mara-matnr,
        mtart TYPE mara-mtart,
      END OF ty_mara.

    CLASS-METHODS get_data
      IMPORTING VALUE(iv_mtart) TYPE mara-mtart
      EXPORTING VALUE(et_data) TYPE STANDARD TABLE OF ty_mara.

ENDCLASS.

CLASS zcl_amdp_demo IMPLEMENTATION.

  METHOD get_data
    BY DATABASE PROCEDURE
    FOR HDB
    LANGUAGE SQLSCRIPT
    OPTIONS READ-ONLY
    USING mara.

    et_data = 
      SELECT matnr, mtart
      FROM mara
      WHERE mtart = :iv_mtart;

  ENDMETHOD.

ENDCLASS.

Call AMDP into Program.

DATA: lt_data TYPE STANDARD TABLE OF zcl_amdp_demo=>ty_mara.

CALL METHOD zcl_amdp_demo=>get_data
  EXPORTING
    iv_mtart = 'FERT'
  IMPORTING
    et_data  = lt_data.

LOOP AT lt_data INTO DATA(ls_data).
  WRITE: / ls_data-matnr, ls_data-mtart.
ENDLOOP.