ABAP嵌套优化

提供代码三例。

1、（se30可以找到）

I = 1.
LOOP AT ITAB1 INTO WA1.
   LOOP AT ITAB2 INTO WA2 FROM I.
     IF WA2-K <> WA1-K.
       I = SY-TABIX.
       EXIT.
     ENDIF.
     " ...
   ENDLOOP.
ENDLOOP.

2、（和上述有些不同）

   DATA: fcount TYPE i.
   fcount = 1.
   SORT tvbrk BY vbeln.
   SORT tvbrp BY vbeln.
   LOOP AT tvbrp.
     LOOP AT tvbrk FROM fcount.
       IF tvbrk-vbeln = tvbrp-vbeln.
         fcount = sy-tabix.
         tvbrp-bukrs = tvbrk-bukrs.
         tvbrp-vkorg = tvbrk-vkorg.
         tvbrp-kunag = tvbrk-kunag.
         tvbrp-fkdat = tvbrk-fkdat.
         tvbrp-fkart = tvbrk-fkart.
         MODIFY tvbrp.
         EXIT.
       ENDIF.
     ENDLOOP.
   ENDLOOP.

3、（se30提示）

   LOOP AT tvbrp.
     READ TABLE tvbrk WITH KEY vbeln = tvbrp-vbeln BINARY SEARCH.
     tvbrp-bukrs = tvbrk-bukrs.
     tvbrp-vkorg = tvbrk-vkorg.
     tvbrp-kunag = tvbrk-kunag.
     tvbrp-fkdat = tvbrk-fkdat.
     tvbrp-fkart = tvbrk-fkart.
     MODIFY tvbrp.
   ENDLOOP.