ABAP开发学习——AT NEW/AT END OF

*如果要使用at的事件，首先要对表进行排序
SORT lt_ekpo BY ebeln.
LOOP AT lt_ekpo INTO ls_ekpo.
  ls_ekpo_tmp = ls_ekpo.
  WRITE: / ls_ekpo-ebeln, ls_ekpo-ebelp, ls_ekpo-txz01.
  AT FIRST."执行完内表中的第一条数据，输出
    WRITE: / 'AT First', ls_ekpo_tmp-ebeln, ls_ekpo_tmp-ebelp, ls_ekpo_tmp-txz01.
  ENDAT.
  AT LAST."执行完内表中的最后一条数据，输出
    WRITE: / 'AT LAST', ls_ekpo_tmp-ebeln, ls_ekpo_tmp-ebelp, ls_ekpo_tmp-txz01.
  ENDAT.
  AT NEW ebeln.当字段发生变化并且是其第一次出现，输出
    WRITE: / 'AT NEW EBELN', ls_ekpo_tmp-ebeln, ls_ekpo_tmp-ebelp, ls_ekpo_tmp-txz01.
  ENDAT.
  AT END OF ebeln.当字段发生变化并且是其最后一次出现，输出
    WRITE: / 'AT END OF EBELN', ls_ekpo_tmp-ebeln, ls_ekpo_tmp-ebelp, ls_ekpo_tmp-txz01.
  ENDAT.
ENDLOOP.

可以在输出时实现一些分块