Function Module - Generic Extraction : Not able to solve

Question

Hi Guys,
       I have created a function module. The function module is working well. But when i start the extraction. It does not stops. It starts loading same data package again and again. It is becoming an endless loop. I have ot ask basis person to kill that job. He inturn has to restart SAP r/3 server. This has become a big issue. Guys please help I am attaching the code for your reference
Example: DataSource for table SFLIGHT
TABLES: YSALES,
       MBEW.
  DATA: BEGIN OF I_YSALES OCCURS 0.
          INCLUDE STRUCTURE YSALES.
  DATA: END  OF I_YSALES.
  DATA: BEGIN OF I_MBEW OCCURS 0.
          INCLUDE STRUCTURE MBEW.
  DATA: END OF I_MBEW.
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,
          S_CURSOR1 TYPE CURSOR.
Select ranges
  RANGES: L_R_ZYEAR  FOR YSALES-ZYEAR,
          L_R_ZMONTH  FOR YSALES-ZMONTH.
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 '0SAPI_ysales_SIMPLE'.
     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.
Fill range tables BW will only pass down simple selection criteria
of the type SIGN = 'I' and OPTION = 'EQ' or OPTION = 'BT'.
    LOOP AT S_S_IF-T_SELECT INTO L_S_SELECT WHERE FIELDNM = 'ZYEAR'.
      MOVE-CORRESPONDING L_S_SELECT TO L_R_ZYEAR.
      APPEND L_R_ZYEAR.
    ENDLOOP.
    LOOP AT S_S_IF-T_SELECT INTO L_S_SELECT WHERE FIELDNM = 'ZMONTH'.
      MOVE-CORRESPONDING L_S_SELECT TO L_R_ZMONTH.
      APPEND L_R_ZMONTH.
    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.
     OPEN CURSOR WITH HOLD S_CURSOR FOR
     SELECT (S_S_IF-T_FIELDS)
        FROM YSALES .
     OPEN CURSOR WITH HOLD S_CURSOR1 FOR
      SELECT (S_S_IF-T_FIELDS)
      FROM MBEW WHERE YSALES~MATNR
          AND BWKEY = YSALES~WERKS.
    select  BUKRS
            ZYEAR
            ZMONTH
            WERKS
            MATNR
            SLSCAT
            KNDNR
            SPART
            MATKL
            MENGE
            DMBTR
            VV702
            VV703
            VVADS
            VV704
            VV731
            INTO
            CORRESPONDING FIELDS OF table I_YSALES
            PACKAGE SIZE S_S_IF-MAXSIZE
            FROM YSALES
            WHERE ZYEAR IN L_R_ZYEAR
            AND   ZMONTH IN L_R_ZMONTH.
   ENDSELECT.
        WHERE MATNR IN L_R_MATNR.
        WHERE WERKS = WERKS
        AND   MATNR = MATNR
        AND   KNDNR = KNDNR
        AND   SPART = SPART.
    IF SY-SUBRC = 0.
      SORT I_YSALES BY WERKS MATNR .
    ENDIF.
    IF NOT I_YSALES[] IS INITIAL.
      SELECT MATNR
             BWKEY
             BWTAR
             LBKUM
             SALK3
             BKLAS
             INTO CORRESPONDING FIELDS OF TABLE I_MBEW
             PACKAGE SIZE S_S_IF-MAXSIZE
             FROM MBEW
             FOR ALL ENTRIES IN I_YSALES
             WHERE MATNR = I_YSALES-MATNR
             AND   BWKEY = I_YSALES-WERKS.
      ENDSELECT.
    ENDIF.
    LOOP AT I_YSALES .
      MOVE-CORRESPONDING I_YSALES TO E_T_DATA.
      READ TABLE I_MBEW WITH KEY MATNR = I_YSALES-MATNR
                                 BWKEY = I_YSALES-WERKS.
      IF SY-SUBRC = 0.
        MOVE-CORRESPONDING I_MBEW TO E_T_DATA.
      ENDIF.
      APPEND E_T_DATA.
    ENDLOOP.
   IF SY-SUBRC <> 0.
     CLOSE CURSOR S_CURSOR.
      RAISE NO_MORE_DATA.
    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.
    S_COUNTER_DATAPAKID = S_COUNTER_DATAPAKID + 1.
  ENDIF.              "Initialization mode or data extraction ?
ENDFUNCTION.

Answer 1

Hi Baljit,
This is a dangerous way of extracting your data.
I am not surprised that it has become an endless loop.
You have to use the cursor and the fetch statement and after the fetch statement you have to use a subreturncode
to wonder if the fetch statement did get any data.
if not use the folowing statements.
close cursor s_cursor.
raise no_more_data.
In your situation the select statement will start every time from the first record in the table ysales because you don't use the cursor. By using the cursor and the fetch statement, the fetch statement will start from the cursor everytime it calls the function module.
I guess this function module is part of an endless loop and will be exited at the moment that the function module returns with raise no_more_data. (in other words, the cursor is at the last record of the table ysales, so no more records will be found)
Hope this will help
Maarten