Mapping a parent-child relationship on a single table

ann_meads · **Posted:** Fri Feb 15, 2008 5:46 am

Is it possible to map a parent-child relationship on the same table in Hibernate?

For example,

<class name="tlss.TLSSProcess" table="TLSS_PROCESSES">
<id name="id" column="ID">
<generator class="native"/>
</id>

<many-to-one name="parent"
class="tlss.TLSSProcess"
column="tlss_process_id"/>

<set name="children" inverse="true" >
<key column="ID"/>
<one-to-many class="tlss.TLSSProcess"/>
</set>

In trying to save instances of this class, I was getting transient object issues. Where would it be best to put the cascade="all"? Tried putting it on the children and I got concurrency issues.

somu_ngm1 · **Joined:** Wed Jun 20, 2007 1:53 am **Posts:** 75

Your set asscoiation is wrong. It should be,

<set name="children" inverse="true" >
<key column="tlss_process_id"/>
<one-to-many class="tlss.TLSSProcess"/>
</set>

ann_meads · **Posted:** Fri Feb 15, 2008 12:11 pm

Thank you for your reply.

I did notice that error and have changed it. However, I'm still getting a concurrent modification exception. Any suggestions?

Regards,
Ann

somu_ngm1 · **Joined:** Wed Jun 20, 2007 1:53 am **Posts:** 75

Post your code between session.open and session.close()

ann_meads · **Posted:** Mon Feb 18, 2008 5:41 am

The problem is that we are trying to pass an instance associated with Hibernate to a rules engine (jrules). This will fire rules and add things to the instance that we cannot predict. Perhaps we cannot do it this way but it would be nice if we could!

Thanks, Ann

Code:

TlssrulesResult tlssrulesresult = null;
      session = HibernateUtil.getSessionFactory().getCurrentSession();
      session.beginTransaction();
      
   
      ContractDao contractDao = new  ContractDao();
      contract = contractDao.getContract("aston", session);
      
      ContractConstraint cc = new ContractConstraint("cc1", "SOM level", contract, tlss.SOM.CapabilityServiceOnBalanceSheet);
      Parameter opConst1 = new Parameter("opConst1","operational_autonomy","yes");
      ContractConstraint cc2 = new ContractConstraint("cc2", "support constraint",contract,opConst1);

      Parameter opConst2 = new Parameter("opConst2","mission_profile","yes");
      ContractConstraint cc3 = new ContractConstraint("cc3", "support constraint",contract,opConst2);

      Parameter opConst3 = new Parameter("opConst3","accessibility_in_theatre","yes");
      ContractConstraint cc4 = new ContractConstraint("cc4", "support constraint",contract,opConst3);

      
      IlrRuleSessionProvider rsProvider = new IlrRuleSessionProviderFactory.Builder(
            IlrRuleSessionProviderFactory.SIMPLE_RULESESSION_PROVIDER).build();

      IlrStatelessRuleSession rs = rsProvider   .createStatelessRuleSession();

      IlrSessionRequest request1 = new IlrSessionRequest(rulesetPath);
      
      IlrSessionExecutionSettings execSettings = request1.getExecutionSettings();
      IlrSessionParameters params = execSettings.getInputParameters();
      params.setParameter("contract", contract);

      // Executes the ruleset
      IlrSessionResponse response1 = rs.executeRules(request1);
   
      tlssrulesresult = new TlssrulesResult();        
      
      tlssrulesresult.contract = (Contract) response1.getExecutionResult().getOutputParameters().getObjectValue(
      "contract");
      
      
      tlssrulesresult.userdata = (String)response1.getExecutionProperties().getUserData();
      tlssrulesresult.outputString = response1.getExecutionResult().getOutputString();

      
      session.saveOrUpdate(contract);
      session.getTransaction().commit();