Generic Delta extraction by Function module issue

Question

Hello Experts,
Please help !!!
I have problem for delta extraction by Function module.  For the full load, I wrote function module based on RSAX_BIW_GET_DATA_SIMPLE. It works fine.
But I would like to have the delta load enabled. Therefore, I modified the datasource, add a delta specific field u2018ztimestampu2019, which type is calendar day.
Then I create a function module based on template u2018RSAX_BIW_GET_DATAu2019, as this support the upload mode. But when I test this datasource in RSA3, no matter itu2019s full load or initial delta load, it always send me an error, u201CErrors occurred during the extractionu201D.
I had some debug, and found that there is no value  for i_isource when my function module is called. Therefore it raised the exception.
But I do not have the chance to debug my code for the delta logic, can somebody help to check?
I also check the entries in ROOSOURCE,
For my datasource ZTRNREC_FM_DELTA, The DELTA value is u2018AIEu2019, and extraction method is u2018F2u2019, should I change them to DELTA= u2018Du2019 and extraction method to u2018F1u2019? Where to change?
FUNCTION ZRSAX_TRAININGREC_DELTA.
""Local Interface:
*"  IMPORTING
*"     VALUE(I_REQUNR) TYPE  SBIWA_S_INTERFACE-REQUNR
*"     VALUE(I_ISOURCE) TYPE  SBIWA_S_INTERFACE-ISOURCE OPTIONAL
*"     VALUE(I_MAXSIZE) TYPE  SBIWA_S_INTERFACE-MAXSIZE OPTIONAL
*"     VALUE(I_INITFLAG) TYPE  SBIWA_S_INTERFACE-INITFLAG OPTIONAL
*"     VALUE(I_UPDMODE) TYPE  SBIWA_S_INTERFACE-UPDMODE OPTIONAL
*"     VALUE(I_DATAPAKID) TYPE  SBIWA_S_INTERFACE-DATAPAKID OPTIONAL
*"     VALUE(I_PRIVATE_MODE) OPTIONAL
*"     VALUE(I_CALLMODE) LIKE  ROARCHD200-CALLMODE OPTIONAL
*"     VALUE(I_REMOTE_CALL) TYPE  SBIWA_FLAG DEFAULT SBIWA_C_FLAG_OFF
*"  TABLES
*"      I_T_SELECT TYPE  SBIWA_T_SELECT OPTIONAL
*"      I_T_FIELDS TYPE  SBIWA_T_FIELDS OPTIONAL
*"      E_T_DATA STRUCTURE  ZTRN_REC_TIME OPTIONAL
*"      E_T_SOURCE_STRUCTURE_NAME OPTIONAL
*"  EXCEPTIONS
*"      NO_MORE_DATA
*"      ERROR_PASSED_TO_MESS_HANDLER
The input parameter I_DATAPAKID is not supported yet !
Example: InfoSource containing TADIR objects
Auxiliary Selection criteria structure
  DATA: l_s_select TYPE sbiwa_s_select.
Maximum number of lines for DB table
  STATICS: l_maxsize TYPE sbiwa_s_interface-maxsize,
          S_S_IF TYPE SRSC_S_IF_SIMPLE,
          S_COUNTER_DATAPAKID LIKE SY-TABIX.
Parameter I_PRIVATE_MODE:
Some applications might want to use this function module for other
purposes as well (e.g. data supply for OLTP reporting tools). If the
processing logic has to be different in this case, use the optional
parameter I_PRIVATE_MODE (not supplied by BIW !) to distinguish
between BIW calls (I_PRIVATE_MODE = SPACE) and other calls
(I_PRIVATE_MODE = X).
If the message handling has to be different as well, define Your own
messaging macro which interprets parameter I_PRIVATE_MODE. When
called by BIW, it should use the LOG_WRITE macro, otherwise do what
You want.
Initialization mode (first call by SAPI) or data transfer mode
(following calls) ?
  IF i_initflag = sbiwa_c_flag_on.
Initialization: check input parameters
                buffer input parameters
                prepare data selection
The input parameter I_DATAPAKID is not supported yet !
Invalid second initialization call -> error exit
    IF NOT g_flag_interface_initialized IS INITIAL.
      IF 1 = 2. MESSAGE e008(r3). ENDIF.
      log_write 'E'                    "message type
                'R3'                   "message class
                '008'                  "message number
                ' '                    "message variable 1
                ' '.                   "message variable 2
      RAISE error_passed_to_mess_handler.
    ENDIF.
Check InfoSource validity
    CASE i_isource.
      WHEN 'ZTRNREC_FM_DELTA'.
      WHEN OTHERS.
        IF 1 = 2. MESSAGE e009(r3). ENDIF.
        log_write 'E'                  "message type
                  'R3'                 "message class
                  '009'                "message number
                  i_isource            "message variable 1
                  ' '.                 "message variable 2
        RAISE error_passed_to_mess_handler.
    ENDCASE.
Check for supported update mode
    CASE i_updmode.
      WHEN 'F'.
      WHEN 'D'.
      WHEN 'R'.
      WHEN OTHERS.
        IF 1 = 2. MESSAGE e011(r3). ENDIF.
        log_write 'E'                  "message type
                  'R3'                 "message class
                  '011'                "message number
                  i_updmode            "message variable 1
                  ' '.                 "message variable 2
        RAISE error_passed_to_mess_handler.
    ENDCASE.
Check for obligatory selection criteria
    APPEND LINES OF i_t_select TO g_t_select.
Fill parameter buffer for data extraction calls
    g_s_interface-requnr    = i_requnr.
    g_s_interface-isource   = i_isource.
    g_s_interface-maxsize   = i_maxsize.
    g_s_interface-initflag  = i_initflag.
    g_s_interface-updmode   = i_updmode.
    g_s_interface-datapakid = i_datapakid.
    g_flag_interface_initialized = sbiwa_c_flag_on.
Fill field list table for an optimized select statement
(in case that there is no 1:1 relation between InfoSource fields
and database table fields this may be far from beeing trivial)
    APPEND LINES OF i_t_fields TO g_t_segfields.
  ELSE.                 "Initialization mode or data extraction ?
Data transfer: First Call      OPEN CURSOR + FETCH
               Following Calls FETCH only
  LOOP AT G_T_SELECT INTO L_S_SELECT
        WHERE FIELDNM = 'ZTIMESTAMP'.
  ENDLOOP.
      IF G_COUNTER_DATAPAKID = 0.
        IF L_S_SELECT-LOW = '' AND L_S_SELECT-HIGH = ''.
        OPEN CURSOR WITH HOLD G_CURSOR FOR
            SELECT (g_t_fields)
            FROM ZTRN_REC_TIME.
        ELSE.
          OPEN CURSOR WITH HOLD G_CURSOR FOR
            SELECT (g_t_fields)
            FROM ZTRN_REC_TIME
            WHERE ZTIMESTAMP >= L_S_SELECT-LOW
              AND ZTIMESTAMP  <= L_S_SELECT-HIGH.
        ENDIF.
      ENDIF.
  FETCH NEXT CURSOR G_CURSOR
               APPENDING CORRESPONDING FIELDS
               OF TABLE E_T_DATA
               PACKAGE SIZE S_S_IF-MAXSIZE.
    IF SY-SUBRC <> 0.
      CLOSE CURSOR G_CURSOR.
      RAISE NO_MORE_DATA.
    ENDIF.
    S_COUNTER_DATAPAKID = S_COUNTER_DATAPAKID + 1.
  ENDIF.
ENDFUNCTION.
I found some similar issue in this forum by link
Generic Extractor Delta Function Module code, but still I could not get clear answer.
Can you please help me:
1)     why there is no value for i_source , how to fix it?
2)     For the delta logic for ztimestemp, is it correct?
3)     Need I modify the entries in ROOSOURCE ?
Thanks a lot !!!

Answer 1

Hello Andre,
        Thanks a lot for your help. I did some change , but still does not work. Could you please help check.
Now the source code are the following, It's based on the RSAX_BIW_GET_DATA_SIMPLE, as you confirm that this also supply the update mode (full, initial delta, delta).
FUNCTION RSAX_BIW_GET_DATA_TRAININGREC1.
""Local Interface:
*"  IMPORTING
*"     VALUE(I_REQUNR) TYPE  SRSC_S_IF_SIMPLE-REQUNR
*"     VALUE(I_DSOURCE) TYPE  SRSC_S_IF_SIMPLE-DSOURCE OPTIONAL
*"     VALUE(I_MAXSIZE) TYPE  SRSC_S_IF_SIMPLE-MAXSIZE OPTIONAL
*"     VALUE(I_INITFLAG) TYPE  SRSC_S_IF_SIMPLE-INITFLAG OPTIONAL
*"     VALUE(I_READ_ONLY) TYPE  SRSC_S_IF_SIMPLE-READONLY OPTIONAL
*"     VALUE(I_REMOTE_CALL) TYPE  SBIWA_FLAG DEFAULT SBIWA_C_FLAG_OFF
*"  TABLES
*"      I_T_SELECT TYPE  SRSC_S_IF_SIMPLE-T_SELECT OPTIONAL
*"      I_T_FIELDS TYPE  SRSC_S_IF_SIMPLE-T_FIELDS OPTIONAL
*"      E_T_DATA STRUCTURE  ZTRN_REC_TIME OPTIONAL
*"  EXCEPTIONS
*"      NO_MORE_DATA
*"      ERROR_PASSED_TO_MESS_HANDLER
Auxiliary Selection criteria structure
  DATA: L_S_SELECT TYPE SRSC_S_SELECT.
Maximum number of lines for DB table
  STATICS: S_S_IF TYPE SRSC_S_IF_SIMPLE,
counter
          S_COUNTER_DATAPAKID LIKE SY-TABIX,
cursor
          S_CURSOR TYPE CURSOR.
Select ranges
RANGES:
        L_R_ZTIMESTAMP FOR ZTRN_REC_TIME-ZTIMESTAMP.
Initialization mode (first call by SAPI) or data transfer mode
(following calls) ?
  IF I_INITFLAG = SBIWA_C_FLAG_ON.
Initialization: check input parameters
                buffer input parameters
                prepare data selection
Check DataSource validity
    CASE I_DSOURCE.
      WHEN 'ZTRNREC_FM'.
      WHEN OTHERS.
        IF 1 = 2. MESSAGE E009(R3). ENDIF.
this is a typical log call. Please write every error message like this
        LOG_WRITE 'E'                  "message type
                  'R3'                 "message class
                  '009'                "message number
                  I_DSOURCE   "message variable 1
                  ' '.                 "message variable 2
        RAISE ERROR_PASSED_TO_MESS_HANDLER.
    ENDCASE.
    APPEND LINES OF I_T_SELECT TO S_S_IF-T_SELECT.
Fill parameter buffer for data extraction calls
    S_S_IF-REQUNR    = I_REQUNR.
    S_S_IF-DSOURCE = I_DSOURCE.
    S_S_IF-MAXSIZE   = I_MAXSIZE.
Fill field list table for an optimized select statement
(in case that there is no 1:1 relation between InfoSource fields
and database table fields this may be far from beeing trivial)
    APPEND LINES OF I_T_FIELDS TO S_S_IF-T_FIELDS.
  ELSE.                 "Initialization mode or data extraction ?
Data transfer: First Call      OPEN CURSOR + FETCH
               Following Calls FETCH only
First data package -> OPEN CURSOR
    IF S_COUNTER_DATAPAKID = 0.
      LOOP AT S_S_IF-T_SELECT INTO L_S_SELECT WHERE FIELDNM = 'ZTIMESTAMP'.
      MOVE-CORRESPONDING L_S_SELECT TO L_R_ZTIMESTAMP.
      APPEND L_R_ZTIMESTAMP.
      ENDLOOP.
Determine number of database records to be read per FETCH statement
from input parameter I_MAXSIZE. If there is a one to one relation
between DataSource table lines and database entries, this is trivial.
In other cases, it may be impossible and some estimated value has to
be determined.
     IF L_S_SELECT-LOW = '' AND L_S_SELECT-HIGH = ''.
        OPEN CURSOR WITH HOLD S_CURSOR FOR
        SELECT (S_S_IF-T_FIELDS)
        FROM ZTRN_REC_TIME.
        ELSE.
        OPEN CURSOR WITH HOLD G_CURSOR FOR
        SELECT (S_S_IF-T_FIELDS)
        FROM ZTRN_REC_TIME
        WHERE ZTIMESTAMP >= L_S_SELECT-LOW
        AND ZTIMESTAMP <= L_S_SELECT-HIGH.
     ENDIF.
    ENDIF.                             "First data package ?
Fetch records into interface table.
  named E_T_'Name of extract structure'.
    FETCH NEXT CURSOR S_CURSOR
               APPENDING CORRESPONDING FIELDS
               OF TABLE E_T_DATA
               PACKAGE SIZE S_S_IF-MAXSIZE.
    IF SY-SUBRC <> 0.
      CLOSE CURSOR S_CURSOR.
      RAISE NO_MORE_DATA.
    ENDIF.
    S_COUNTER_DATAPAKID = S_COUNTER_DATAPAKID + 1.
  ENDIF.              "Initialization mode or data extraction ?
ENDFUNCTION.
I think it already includes the important statements you suggested.
I test this FM in RSA3, for the Full load mode, it works fine. Also if I checked the debug mode in execution , it will stop in the code and let me debug.
But when I choose other mode, like 'initializion of the delta transfer'  or simulation of initial delta, I always get error 'error occurs  during the extraction' .. even I choose debug mode, but it could not enter the code for debug..
Till now I did not see any parameter or value for the upload mode..
Another questions is that, in RSO2, I define Ztimestamp as my delta field.. But , can I add other field as selection condition in the datasource definition, and has its range table in this function module ?
Should I change the entries in ROOSOURCE for this datasource ??
Please let me know your feedback, do you have some concret example for generic delta extraction ?
Thanks a lot !