Columns in a dynamic table

Question

Hi guys!
I'm working with field symbols and dynamic tables and i have this code:
REPORT  zpractica03.
PARAMETERS: p_tabla TYPE dd02l-tabname.
DATA: tabla_name TYPE dd02l-tabname,
      tabla_generica  TYPE REF TO data,
      linea_generica  TYPE REF TO data.
FIELD-SYMBOLS: <fs_tabla> TYPE ANY TABLE,
               <fs_linea> TYPE ANY,
               <fs_campo> TYPE ANY.
tabla_name = p_tabla.
CREATE DATA tabla_generica TYPE STANDARD TABLE OF (tabla_name).
ASSIGN tabla_generica->* TO <fs_tabla>.
CREATE DATA linea_generica TYPE (tabla_name).
ASSIGN linea_generica->* TO <fs_linea>.
SELECT *
       INTO CORRESPONDING FIELDS OF TABLE <fs_tabla>
       FROM (tabla_name).
DATA: lv_indice_campo TYPE sy-tabix,
      lv_valor_campo.
LOOP AT <fs_tabla> INTO <fs_linea>.
  CLEAR lv_indice_campo.
  lv_indice_campo = sy-tabix.
     ASSIGN COMPONENT lv_indice_campo OF STRUCTURE <fs_linea> TO <fs_campo>.
    IF sy-subrc EQ 0.
      MOVE <fs_campo> TO lv_valor_campo.
    ENDIF.
ENDLOOP.
In the last step, I know that I need something like this in order to get one line and save the info in a workarea and then create an ALV :
Do n Times
     ASSIGN COMPONENT lv_indice_campo OF STRUCTURE <fs_linea> TO <fs_campo>.
    IF sy-subrc EQ 0.
      MOVE <fs_campo> TO lv_valor_campo.
    ENDIF.
Enddo.
What I don't know how to do is how can I get the number 'N' ? Can somebody explain me how can I get the number of the columns in a table that can be different any time that i run the program?
Thank you very much.
Gaby

Answer 1

Hello,
You can use the FM: DDIF_FIELDINFO_GET & pass the table name tabla_name.
It will return the table DFIES_TAB which will contain the column details. So before this:
Do n Times
lv_indice_campo = lv_indice_campo + 1.
ASSIGN COMPONENT lv_indice_campo OF STRUCTURE <fs_linea> TO <fs_campo>.
IF sy-subrc EQ 0.
MOVE <fs_campo> TO lv_valor_campo.
ENDIF.
Enddo.
Add this code:
DATA: LT_DFIES        TYPE STANDARD TABLE OF DFIES.
    CALL FUNCTION 'DDIF_FIELDINFO_GET'
      EXPORTING
        TABNAME        = tabla_name
      TABLES
        DFIES_TAB      = LT_DFIES
      EXCEPTIONS
        NOT_FOUND      = 1
        INTERNAL_ERROR = 2
        OTHERS         = 3.
    IF SY-SUBRC = 0.
      N = LINES ( LT_DFIES ).
    ENDIF.
Else you can easily avoid this stuff by EXITing the DO...ENDDO loop.
Do.
lv_indice_campo = lv_indice_campo + 1.
ASSIGN COMPONENT lv_indice_campo OF STRUCTURE <fs_linea> TO <fs_campo>.
IF sy-subrc EQ 0.
  MOVE <fs_campo> TO lv_valor_campo.
ELSE.
  EXIT.
ENDIF.
Enddo.
Hope i am clear.
BR,
Suhas