Problem with Persistent Object as Reference Attribute of Persistent Object

Question

Hello All,
I have a problem with a persistent class that contains a reference attribute to another persistent class.  I can write the reference object attribute to the DB but when I read the reference attribute back from the DB the object is null.  Allow me to explain...
I have two tables; one is a data table with one key field of type OS_GUID, the second is a mapping table with several business key fields and two further fields; an instance GUID and a class identifier GUID.  The data table is used to contain all the data for an object.  The mapping table is used to hold a relationship between the GUID assigned in the data table and the business key.  The mapping table has been structured in this way by following the help here:
http://help.sap.com/saphelp_erp2005vp/helpdata/en/df/e785a9e87111d4b2eb0050dadfb92b/frameset.htm
and the field mapping in persistent class for the mapping table has been mapped following the help here:
http://help.sap.com/saphelp_erp2005vp/helpdata/en/06/f23c33638d11d4966d00a0c94260a5/frameset.htm
The code I use to create entries in the data and mapping table is:
<-snip->
  DATA:
    gv_blank_data_guid TYPE REF TO zcl_ps_data,
    gv_data_guid       TYPE        os_guid,
    go_data_ps         TYPE REF TO zcl_ps_data,
    go_data_agent      TYPE REF TO zca_ps_data,
    go_data_map_ps     TYPE REF TO zcl_ps_data_map,
    go_data_map_agent  TYPE REF TO zca_ps_data_map,
    go_exc             TYPE REF TO cx_root.
  go_data_agent = zca_ps_data=>agent.
  go_data_map_agent = zca_ps_data_map=>agent.
  TRY.
Check if there's already data with the business key on the DB
      go_data_map_ps = go_data_map_agent->get_persistent(
                         i_data_ref     = iv_data_ref
                         i_action       = iv_action ).
... if there is then exit.
      EXIT.
    CATCH cx_root INTO go_exc.
  ENDTRY.
  TRY.
Create the data...
      go_data_ps = go_data_agent->create_persistent(
                       i_root_guid = gv_blank_data_guid
                       i_req_date  = iv_req_date ).
      TRY.
... finally, write the new data to the data business key map table
          go_data_map_ps = go_data_map_agent->create_persistent(
                             i_data_ref     = iv_data_ref
                             i_action       = iv_action
                             i_data_guid    = go_data_ps ).    "note1
        CATCH cx_root INTO go_exc.
      ENDTRY.
    CATCH cx_os_object_not_found.
  ENDTRY.
  COMMIT WORK.
<-snip->
The fact that it is possible to pass the object GO_DATA_PS in the call to GO_DATA_MAP_AGENT (the line that I've put the comment "note1" on) indicates to me that the reference to the data persistent object can be written to the DB by the mapping persistent object.  After executing the above code the mapping table object and class identifier fields are populated.  Also, if multiple entries are written to the tables then the class identifier field in the mapping table is always the same and the object ID is different as expected.
However, the problem I have is if I read an object from the DB using the business key with the following code:
<-snip->
  DATA:
    gv_req_date        type        datum,
    gv_data_guid       TYPE        os_guid,
    go_data_ps         TYPE REF TO zcl_ps_data,
    go_data_agent      TYPE REF TO zca_ps_data,
    go_data_map_ps     TYPE REF TO zcl_ps_data_map,
    go_data_map_agent  TYPE REF TO zca_ps_data_map,
    go_exc             TYPE REF TO cx_root.
  go_data_agent = zca_ps_data=>agent.
  go_data_map_agent = zca_ps_data_map=>agent.
  TRY.
Read data mapping with the business key
      go_data_map_ps = go_data_map_agent->get_persistent(
                         i_data_ref     = iv_data_ref
                         i_action       = iv_action ).
... then read the data.
      TRY.
          CALL METHOD go_data_map_ps->get_data_guid
            RECEIVING
              result = go_data_ps.
        CATCH cx_os_object_not_found.
      ENDTRY.
    CATCH cx_root INTO go_exc.
  ENDTRY.
<-snip->
At no point during this code are the attributes of the object of the persistent class for the data table populated with the contents of the fields of the data table referenced as the attribute of the mapping table.  To clarify, when viewing the object in the debugger all the attributes of the mapping object that are simple table fields are populated with the values of the fields of in the mapping table, however, the attributes of the object that represents the persistent class for the data table are not populated with the fields of the data table.  I had hoped that by reading the mapping table object the data object would automatically be populated.  Is there another step I need to perform to populate the data object?
I'm sorry if the above is hard to follow.  Without being able to provide screenshots it's difficult to explain.
If someone has managed to store references to persistent objects in a table and then read the references back could you list the steps you went through to create the persistent classes and include the code that reads the objects please?  The code I have almost works, I must be just missing some subtle point...
Thanks in advance,
Steve.

Answer 1

Hi Andrea,
The iObject being replicated at item level for Service Complaints is the SAP standard behaviour.
Generally we raise complaint refering to some sales or service issues. In your scenario you are trying to create a complaint based on an iObject, then you have to mention the corresponding product details. I dont see any business requirement not to copy the iObject product at the item level.
If you want it then I think only you have to write a Z program for it.
Hope this helps!
Regards,
Chethan