Modifying database table in ALV Grid

Question

Hi all.
I need to be able to modify the database table in ALV Grid. Here's the code. The database table, that is displayed is 'zng_so_head', it's internal table is 'res_tab'. In the program i tried to create a button 'CHANGE' on the ALV-toolbar, but when executing the program there's no such button (why?). What code, screens, screen elements, etc. should be added to this program to provide a possibility of changing data of the database table 'zng_so_head' (i mean changing existing data, adding new lines and saving changes)?
CODE:
& Report  ZNG_ALV_TC_EDIT_SIMP&
REPORT  ZNG_ALV_TC_EDIT_SIMP.
*-- GLOBAL DATA DECLARATIONS FOR ALV
DATA gr_alvgrid TYPE REF TO cl_gui_alv_grid.
DATA gc_custom_control_name TYPE scrfname VALUE 'CC_ALV'.
DATA gr_ccontainer TYPE REF TO cl_gui_custom_container.
DATA gt_fieldcat TYPE lvc_t_fcat.
DATA gs_layout TYPE lvc_s_layo.
TABLES: zng_so_head, zng_cust, zng_vendors.
*-- STRUCTURE OF INTERNAL TABLE
TYPES: BEGIN OF in_tab,
        so_num TYPE zng_so_head-so_num,          "type numc
        vend_num TYPE zng_so_head-vend_num,      "type numc
        cust_num TYPE zng_so_head-cust_num,      "type numc
        so_date TYPE zng_so_head-so_date,        "type dats
       END OF in_tab.
*-- INTERNAL TABLE HOLDING LIST DATA
DATA res_tab TYPE TABLE OF in_tab WITH HEADER LINE.
*-- FILLING IN INTERNAL TABLE
SELECT hso_num hvend_num hcust_num hso_date
INTO TABLE res_tab FROM zng_so_head AS h.
*&      Form  prepare_field_catalog
FORM prepare_field_catalog CHANGING pt_fieldcat TYPE lvc_t_fcat.
  DATA ls_fcat TYPE lvc_s_fcat.
  ls_fcat-fieldname = 'SO_NUM'.
  ls_fcat-inttype = 'N'.
  ls_fcat-ref_table = 'zng_so_head'.
  ls_fcat-outputlen = '12'.
  ls_fcat-coltext = 'SO_NUM'.
  ls_fcat-seltext = 'SO_NUM'.
  APPEND ls_fcat TO pt_fieldcat.
  CLEAR ls_fcat.
  ls_fcat-fieldname = 'VEND_NUM'.
  ls_fcat-inttype = 'N'.
  ls_fcat-ref_table = 'zng_so_head'.
  ls_fcat-outputlen = '12'.
  ls_fcat-coltext = 'VEND_NUM'.
  ls_fcat-seltext = 'VEND_NUM'.
  APPEND ls_fcat TO pt_fieldcat.
  CLEAR ls_fcat.
  ls_fcat-fieldname = 'CUST_NUM'.
  ls_fcat-inttype = 'N'.
  ls_fcat-ref_table = 'zng_so_head'.
  ls_fcat-outputlen = '12'.
  ls_fcat-coltext = 'CUST_NUM'.
  ls_fcat-seltext = 'CUST_NUM'.
  APPEND ls_fcat TO pt_fieldcat.
  CLEAR ls_fcat.
  ls_fcat-fieldname = 'SO_DATE'.
  ls_fcat-inttype = 'D'.
  ls_fcat-ref_table = 'zng_so_head'.
  ls_fcat-outputlen = '12'.
  ls_fcat-coltext = 'SO_DATE'.
  ls_fcat-seltext = 'SO_DATE'.
  APPEND ls_fcat TO pt_fieldcat.
ENDFORM.                    "prepare_field_catalog
*&      Form  display_alv
FORM display_alv.
  IF gr_alvgrid IS INITIAL.
    CREATE OBJECT gr_ccontainer
    EXPORTING container_name = gc_custom_control_name.
    CREATE OBJECT gr_alvgrid
    EXPORTING i_parent = gr_ccontainer.
    PERFORM prepare_field_catalog CHANGING gt_fieldcat.
    CALL METHOD gr_alvgrid->set_table_for_first_display
      EXPORTING
        is_layout       = gs_layout
      CHANGING
        it_outtab       = res_tab[]
        it_fieldcatalog = gt_fieldcat.
  ELSE.
    CALL METHOD gr_alvgrid->refresh_table_display.
  ENDIF.
ENDFORM.                    "display_alv
      CLASS lcl_event_handler DEFINITION
CLASS lcl_event_handler DEFINITION.
  PUBLIC SECTION.
    METHODS:
    handle_toolbar
      FOR EVENT toolbar OF cl_gui_alv_grid
        IMPORTING e_object
                  e_interactive.
ENDCLASS.             "lcl_event_handler DEFINITION
      CLASS lcl_event_handler IMPLEMENTATION
CLASS lcl_event_handler IMPLEMENTATION.
  METHOD handle_toolbar.
    DATA: ls_toolbar TYPE stb_button.
    MOVE 3 TO ls_toolbar-butn_type.
    APPEND ls_toolbar TO e_object->mt_toolbar.
    CLEAR ls_toolbar.
    MOVE 'CHANGE' TO ls_toolbar-function.
    MOVE icon_change TO ls_toolbar-icon.
    MOVE 'change' TO ls_toolbar-quickinfo.
    MOVE 'change' TO ls_toolbar-text.
    APPEND ls_toolbar TO e_object->mt_toolbar.
  ENDMETHOD.                    "handle_toolbar
ENDCLASS.                    "lcl_event_handler IMPLEMENTATION
DATA object_ref TYPE REF TO lcl_event_handler.
START-OF-SELECTION.
  CALL SCREEN 100.
MODULE STATUS_0100 OUTPUT
MODULE display_alv OUTPUT.
  SET PF-STATUS 'SCREEN_100'.
  PERFORM display_alv.
  CREATE OBJECT object_ref.
  SET HANDLER object_ref->handle_toolbar FOR gr_alvgrid.
ENDMODULE.                    "display_alv OUTPUT
MODULE USER_COMMAND_0100 INPUT
MODULE user_command_0100 INPUT.
  IF sy-ucomm = 'BACK' OR
     sy-ucomm = 'EXIT' OR
     sy-ucomm = 'CANCEL'.
    LEAVE PROGRAM.
  ELSE.
    CALL METHOD object_ref->handle_toolbar.
  ENDIF.
ENDMODULE.                    "status_0100 INPUT
END OF CODE
Thanks all.

Answer 1

Hi,
For the button on the toolbar,here is the code:
CLASS lcl_eh IMPLEMENTATION.
*METHOD:      HANDLE_TOOLBAR
*DESCRIPTION: This method provides the necessary detail required to
             create an extra button in the toolbar.
  METHOD handle_toolbar.
    CLEAR ls_toolbar.
    MOVE 'CHANGE' TO ls_toolbar-function.
    MOVE 0 TO ls_toolbar-butn_type.
    MOVE CHANGETO ls_toolbar-text.
    MOVE 'ICON_DETAIL' TO ls_toolbar-icon.
    MOVE 'CHANGE' TO ls_toolbar-quickinfo.
    APPEND ls_toolbar TO e_object->mt_toolbar.
  ENDMETHOD.                    "handle_toolbar
Also,if you are using the CHANGE button to record changes in the DB,then in the local class that you have defined,you should use the following method and then write the logic:
*METHOD:      HANDLE_USER_COMMAND
  METHOD handle_user_command.
    CASE e_ucomm.
      WHEN 'CHANGE'.
CHECK_CHANGED_DATA
REFRESH_TABLE_DISPLAY
Now call the methods that i have given in my previous post.This function code will be checked at the event you click the button 'CHANGE'.I think you have done this in an ELSE condition in the PAI of the screen.Not too sure if it works in the PAI.
Regards,
Beejal
**Reward if this helps