BAPI: TRANSACTION_BEGIN的作用

大概知道是启动一个新会话，

CALL FUNCTION 'TRANSACTION_BEGIN'

业务数据处理，

CALL FUNCTION 'TRANSACTION_END'

详细功能不清楚。

      CLEAR G_TRANSACTION_ID.
 
**.Transaction control for BAPIs
      CALL FUNCTION 'TRANSACTION_BEGIN'
        IMPORTING
          TRANSACTION_ID = G_TRANSACTION_ID.
**.BAPIs for Creating/Changing Matl Data
      CALL FUNCTION 'BAPI_MATERIAL_SAVEDATA'
        EXPORTING
          HEADDATA       = WA_HEADER
          PLANTDATA      = WA_MARC
          PLANTDATAX     = WA_MARCX
          VALUATIONDATA  = WA_MBEW
          VALUATIONDATAX = WA_MBEWX
        TABLES
          RETURNMESSAGES = IT_RETURN.
 
      READ TABLE IT_RETURN WITH KEY TYPE = 'E'.
      IF SY-SUBRC EQ .
*get reprocess data and error log
        MOVE-CORRESPONDING IT_UPLOAD TO IT_ELOG.
        MOVE IT_RETURN-MESSAGE TO IT_ELOG-REASON.
        APPEND IT_ELOG.
      ELSE.
*get successful log
        MOVE-CORRESPONDING IT_UPLOAD TO IT_SLOG.
        APPEND IT_SLOG.
        CALL FUNCTION 'TRANSACTION_STATUS'
          IMPORTING
            STATUS = G_STATUS_OF_TRANSACTION.
        IF G_STATUS_OF_TRANSACTION = 'COMMIT_WORK'.
          COMMIT WORK AND WAIT.
        ENDIF.
        CALL FUNCTION 'TRANSACTION_END'
          EXPORTING
            TRANSACTION_ID = G_TRANSACTION_ID.
 
      ENDIF.