Mapping question using @OneToOne @PrimaryKeyJoinColumn

Question

I am trying to create a simple web application to maintain a ContractAssignment table.
Created an EJB from this table with @Id of contractNumber.
public class ContractAssignment .....
@Id
@Column(name = "CONTRACT_NUMBER",
nullable = false,updatable=false)
private String contractNumber;
@OneToOne @PrimaryKeyJoinColumn
private Contract contractInfo;
I need contract info that exists in multiple tables so I created a view called Contract.
Created an EJB for this view with @Id of contractNumber.
public class Contract ......
@Id
@Column(name="CONTRACT_NUMBER", nullable = false,updatable=false)
private String contractNumber;
I will only be maintaining the ContractAssignment EJB.
The Contract EJB will NOT be maintained by this app.
It will only be used to obtain valid contract numbers that can be used in ContractAssignment maintenance.
It will also be used to display contract information when maintaining the ContractAssignment.
Is this the right way to map the relationship?
Another question. I've created a search page to look up ContractAssignments.
For some reason, the SQL generated is joining the table to itself.
Not sure if this is because of incorrect mapping (described above).
SQL that was generated:
SELECT t0.CONTRACT_NUMBER, t0.DESCRIPTION, t0.CONTRACT_START_DATE, t0.IMS_STATUS
FROM CONTRACT_ASSIGNMENT t0,
CONTRACT_ASSIGNMENT t1
WHERE (CONTRACT_NUMBER = ?)
     bind => [1234]
from the following OQL:
select o from ContractUserAssignment o where ocontractNumber like :contractNumber
What is causing the incorrect join?
Thank you for any help.

Answer 1

All - Thanks much.. Here is my requirement that is no solved by regular mapping
<Root>
<Recordset>
  <Ordheader>
    <ord>
    <ord_type>
  </Ordheader>
   <Ord_line>
     <ord>
     <Linnum>
   </Ord_line>
  </Recordset>
<Recordset>
  <Ordheader>
    <ord>
    <ord_type>
  </Ordheader>
   <Ord_line>
     <ord>
     <Linnum>
   </Ord_line>
</Recordset>
<Root>
As you see above, each recordset has order transaction. One Root message can contain multiple of these. So, when I map to the IDOC, I want to filter out any ord_type <> XX.
If I use regular graphical map, it only looks at first recordset and accepts all or rejects all.
I need to use UDF. In the UDF, what comes in as input ? Resultset is output -correct ? Now how do I usse graphical mapping with UDF to generate the correct target info