How to update New_Value and Old_value field in CDPOS

Question

Hi,
I've been going through all the article and threads in the this forum. I can;t seem to get the field populate VALUE NEW, VALUE OLD and also the FNAME field always shows as KEY.
My intersion is to update CDPOS everytime there is a value to a record in my z-table being changed.
Below is my trial code. but it does seem to work. I can INSERT  into CDPOS but not UPDATE. Please review my code and let me know how can i get this problem solve please.
REPORT  zvintest1.
TABLES: cdhdr, zvin_test.
DATA: objectclass LIKE cdhdr-objectclas,
      objctid    LIKE cdhdr-objectid,
      stct_old TYPE zvin_test,
      stct_new TYPE zvin_test,
      tablename LIKE cdpos-tabname,
      changenum LIKE cdhdr-changenr.
objectclass = 'ZVIN_ATT'.
objctid = '2711'.
tablename = 'ZVIN_TEST '.
CALL FUNCTION 'CHANGEDOCUMENT_OPEN'
  EXPORTING
    objectclass                   = objectclass
    objectid                      = objctid
  PLANNED_CHANGE_NUMBER         = ' '
   PLANNED_OR_REAL_CHANGES       = 'R'
EXCEPTIONS
   sequence_invalid              = 1
   OTHERS                        = 2
IF sy-subrc <> 0.
MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO
        WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.
ENDIF.
stct_old-vendor = '110'.
stct_old-assembly = 'position'.
stct_old-serialnum = '001'.
stct_old-status = '2'.
*modify zvin_test FROM stct_old.
stct_new-vendor = '110'.
stct_new-assembly = 'position'.
stct_new-serialnum = '001'.
stct_new-status = '1'.
*modify zvin_test FROM stct_old.
CALL FUNCTION 'CHANGEDOCUMENT_SINGLE_CASE'
  EXPORTING
   change_indicator             = 'U'
   DOCU_DELETE                  = 'X'
  REFAREA_NEW                  =  STCT_NEW
  REFAREA_OLD                  =  stct_old
  REFTABLENAME                 = 'ZVIN_TEST'
    tablename                    = tablename
   workarea_new                 = stct_new
   workarea_old                 = stct_old
EXCEPTIONS
   nametab_error                = 1
   open_missing                 = 2
   position_insert_failed       = 3
   OTHERS                       = 4
IF sy-subrc <> 0.
MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO
        WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.
ENDIF.
CALL FUNCTION 'CHANGEDOCUMENT_CLOSE'
  EXPORTING
    date_of_change                = sy-datum
    objectclass                   = objectclass
    objectid                      = objctid
    tcode                         = 'MIGO'
    time_of_change                = sy-uzeit
    username                      = sy-uname
   object_change_indicator       = 'U'
  PLANNED_OR_REAL_CHANGES       = 'R'
   NO_CHANGE_POINTERS            = 'X'
IMPORTING
   changenumber                  = changenum
EXCEPTIONS
   header_insert_failed          = 1
   no_position_inserted          = 2
   object_invalid                = 3
   open_missing                  = 4
   position_insert_failed        = 5
   OTHERS                        = 6
IF sy-subrc <> 0.
MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO
        WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.
ENDIF.
the error i get is NO_POSITION_INSERTED.
Thank you.
Regards,
Vinod

Answer 1

Why don't you use the standard functionality of the record changes?
Go to SE11.. open your table.. go to Technical settings ..
here you can find the "Log data changes". Check this checkbox on.
Later on you can track changes by <b>SCU3</b> transaction code...
This the extract from the online help....
Log data changes
The logging flag defines whether changes to the data records of a table should be logged. If logging is activated, every change (with UPDATE, DELETE) to an existing data record by a user or an application program is recorded in a log table in the database.
Note: Activating logging slows down accesses that change the table. First of all, a record must be written in the log table for each change. Secondly, many users access this log table in parallel. This could cause lock situations even though the users are working with different application tables.
Dependencies
Logging only takes place if parameter rec/client in the system profile is set correctly. Setting the flag on its own does not cause the table changes to be logged.
The existing logs can be displayed with Transaction Table history (SCU3).
Regards,
Naimesh Patel