Left joins : Case or if statement

Question

Hi
I want to know if one can build in a case or if statement into a left join. I want to multiply a value with -1 if the condition is met.

Answer 1

I think it is not possible in SELECT statement...but you can do the below to resolve it.
add a field for FKART in your internal table.
TYPES: BEGIN OF tab ,
       kunag LIKE vbrk-kunag,
       fkdat like vbrk-fkdat,
       matnr LIKE vbrp-matnr,
       werks LIKE vbrp-werks,
       fkart like vbrk-fkart,
       volum LIKE vbrp-volum,
       END OF tab.
DATA: wa_outtab TYPE table of tab WITH HEADER LINE.
SELECT akunag  afkdat
       bmatnr bwerks a~fkart
       SUM( b~volum )
   INTO  table wa_outtab
FROM vbrk AS a
INNER JOIN vbrp AS b
      ON  avbeln  = bvbeln
WHERE
avbeln = bvbeln                                                                               
AND ( afkart LIKE 'F2' OR afkart LIKE 'RE' )
GROUP BY  akunag afkdat bmatnr bwerks a~fkart.
sort wa_outtab.
Loop at wa_outtab.
  if wa_outtab-fkart = 'RE'.
    lpos = lpos +  wa_outtab-volum.
  else.
    lneg = lneg +  wa_outtab-volum.
  endif.
  at end of werks.
     lvaule = lpos - lneg.
    lpos = lneg = 0.
  endat.
endloop.