How to code this logic?

Question

I have an internal table with two fields FLD1 & FLD2(flag). I have to make sure that for same FLD1, there has to be only one FLD2 flag:
    FLD1           FLD2
       A            X
       A           
       B            X
       B            X
       B
For example in the above example, 'B' has two 'X' therefore, I have to give an error message saying " Maintain only one 'X' value for  B"
How do I do this?
Thanks
Sg

Answer 1

try the code given below. It may help to code occording to ur desired logic.
DATA: BEGIN OF it  OCCURS 10,
      fld1 TYPE c,
      fld2 TYPE c,
      END OF it.
PARAMETERS: pfld1 type c .
            pfld2 type  c.
data temp type i.
start-of-SELECTION.
loop at it.
  if it-fld1 = pfld1 and it-fld2 = pfld2.
  temp = 1.
   STOP.
  endif.
   ENDLOOP.
end-of-SELECTION.
if temp = 0.
it-fld1 = pfld1. it-fld2 = pfld2.
append it.
write: / 'data append'.
sort it by fld1.
loop at it.
write: / it-fld1, it-fld2.
ENDLOOP.
else.
WRITE / 'Maintain only one',pfld2, 'value for',pfld1.
it-fld1 = pfld1. it-fld2 = ''.
APPEND it.
sort it by fld1.
loop at it.
write: / it-fld1, it-fld2.
ENDLOOP.
endif.
regards
Vijaykumar Reddy. S