How to create dynamic strcture for a interrnal table

Question

first i created one internal table . with five fields . suppose i want add two more fields in internal table.
what is the code for the this . if any one konow

Answer 1

REPORT  ZTEST05.
PARAMETERS dbtab TYPE tabname DEFAULT 'SPFLI'.
TYPE-POOLS rsds.
DATA tadir_wa  TYPE tadir.
DATA selid     TYPE  rsdynsel-selid.
DATA field_tab TYPE TABLE OF rsdsfields.
DATA table_tab TYPE TABLE OF rsdstabs.
DATA table     LIKE LINE OF table_tab.
DATA cond_tab  TYPE  rsds_twhere.
DATA cond      LIKE LINE OF cond_tab.
DATA dref      TYPE REF TO data.
DATA alv       TYPE REF TO cl_salv_table.
FIELD-SYMBOLS <table> TYPE STANDARD TABLE.
SELECT SINGLE *
       FROM tadir
       INTO tadir_wa
       WHERE pgmid = 'R3TR' AND
             object = 'TABL' AND
             obj_name = dbtab.
IF sy-subrc <> 0.
  MESSAGE 'Database not found' TYPE 'I' DISPLAY LIKE 'E'.
  LEAVE PROGRAM.
ENDIF.
table-prim_tab = dbtab.
APPEND table TO table_tab.
CALL FUNCTION 'FREE_SELECTIONS_INIT'
  EXPORTING
    kind         = 'T'
  IMPORTING
    selection_id = selid
  TABLES
    tables_tab   = table_tab
  EXCEPTIONS
    OTHERS       = 4.
IF sy-subrc <> 0.
  MESSAGE 'Error in initialization' TYPE 'I' DISPLAY LIKE 'E'.
  LEAVE PROGRAM.
ENDIF.
CALL FUNCTION 'FREE_SELECTIONS_DIALOG'
  EXPORTING
    selection_id  = selid
    title         = 'Free Selection'
    as_window     = ' '
  IMPORTING
    where_clauses = cond_tab
  TABLES
    fields_tab    = field_tab
  EXCEPTIONS
    OTHERS        = 4.
IF sy-subrc <> 0.
  MESSAGE 'No free selection created' TYPE 'I'.
  LEAVE PROGRAM.
ENDIF.
READ TABLE cond_tab WITH KEY tablename = dbtab INTO cond.
IF sy-subrc <> 0.
  MESSAGE 'Error in condition' TYPE 'I' DISPLAY LIKE 'E'.
  LEAVE PROGRAM.
ENDIF.
CREATE DATA dref TYPE TABLE OF (dbtab).
ASSIGN dref->* TO <table>.
TRY.
    SELECT *
           FROM (dbtab)
           INTO TABLE <table>
           WHERE (cond-where_tab).
  CATCH cx_sy_dynamic_osql_error.
    MESSAGE 'Error in dynamic Open SQL' TYPE 'I' DISPLAY LIKE 'E'.
    LEAVE PROGRAM.
ENDTRY.
TRY.
    cl_salv_table=>factory(
      IMPORTING r_salv_table = alv
      CHANGING  t_table      = <table> ).
    alv->display( ).
  CATCH cx_salv_msg.
    MESSAGE 'Error in ALV display' TYPE 'I' DISPLAY LIKE 'E'.
ENDTRY.