At first and at new

Question

hi,
   Can anybody tell me wats the difference b/n at first and at new events?

Answer 1

Hi,
  AT FIRST is used for the first record in the internal table processing. This is similar to checking
   IF SY-TABIX = 1.
   ENDIF.
  AT NEW means the new set of record for the particular field in the internal table.
  EX.
  DATA: BEGIN OF ITAB OCCURS 0,
          MATNR TYPE MATNR,
          VBELN TYPE VBELN,
        END OF ITAB.
  SORT ITAB BY MATNR.
For AT NEW is sort is required on the field.
  LOOP AT ITAB.
    AT NEW MATNR.
If the material number changes from the previous one '
the statements between AT NEW MATNR and ENDAT will be *triggered.
    ENDDAT.
  ENDLOOP.
Note: If the "AT NEW field" is not the first field in the internal table structure then you have to sort with those fields also.
    EX.
  DATA: BEGIN OF ITAB OCCURS 0,
          WERKS TYPE WERKS_D,
          MATNR TYPE MATNR,
          VBELN TYPE VBELN,
        END OF ITAB.
  SORT ITAB BY WERKS MATNR.
For AT NEW is sort is required on the field.
  LOOP AT ITAB.
    AT NEW MATNR.
If there is a change in the WERKS also this piece of code will be triggeredt.
    ENDDAT.
  ENDLOOP.
Hope this helps.
Thanks,
Naren