one-to-one relation with subclass.

sdroovan · **Posted:** Wed Jan 05, 2005 2:25 pm

Let's try again...

How can I create a one-to-one relationship in a subclass with a subclass of the same root.
Example:

Class Parent;
|
|-----------------------------------------------------------------------------|
Class Subclass1 extends Parent ..............................Class Subclass2 extends Parent
private Subclass2; //==> how to map such a relation ???

Please, let me know ...
Regards, Stijn.

emmanuel · **Posted:** Thu Jan 06, 2005 3:42 pm

you can't since a true one-to-one imply you have the said id value.

You can map it using a many-to-one however

sdroovan · **Posted:** Fri Jan 07, 2005 12:08 pm

Thanks for your response, but I allready tried to solve it with a many-to-one mapping, but Hibernate still gives the following error:

Code:

16:50:27,375 ERROR JDBCExceptionReporter:58 - Referential Integrity Violation. ADVENTUREBUILDER.RULE references ADVENTUREBUILDER.OPERATION
16:50:27,375 ERROR SessionImpl:2399 - Could not synchronize database state with session
net.sf.hibernate.exception.GenericJDBCException: could not insert: [syntaxtree.Rule#1]
   at net.sf.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:81)
   at net.sf.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:70)
   at net.sf.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:30)
   at net.sf.hibernate.persister.AbstractEntityPersister.convert(AbstractEntityPersister.java:1332)
   at net.sf.hibernate.persister.NormalizedEntityPersister.insert(NormalizedEntityPersister.java:467)
   at net.sf.hibernate.persister.NormalizedEntityPersister.insert(NormalizedEntityPersister.java:429)
   at net.sf.hibernate.impl.ScheduledInsertion.execute(ScheduledInsertion.java:37)
   at net.sf.hibernate.impl.SessionImpl.executeAll(SessionImpl.java:2438)
   at net.sf.hibernate.impl.SessionImpl.execute(SessionImpl.java:2391)
   at net.sf.hibernate.impl.SessionImpl.flush(SessionImpl.java:2260)
   at net.sf.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:61)
   at managing.RuleManagerImpl.addRule(RuleManagerImpl.java:120)
   at managing.RuleManagerImpl.main(RuleManagerImpl.java:160)
Caused by: java.sql.SQLException: Referential Integrity Violation. ADVENTUREBUILDER.RULE references ADVENTUREBUILDER.OPERATION
   at com.pointbase.net.netJDBCPrimitives.handleResponse(Unknown Source)
   at com.pointbase.net.netJDBCPrimitives.handlePrimitiveResponse(Unknown Source)
   at com.pointbase.net.netJDBCPreparedStatement.executeUpdate(Unknown Source)
   at net.sf.hibernate.persister.NormalizedEntityPersister.insert(NormalizedEntityPersister.java:457)
   ... 8 more

I have the following sheme:

Abstract class SyntaxComponent;

2 subclasses:
Class Rule extends SyntaxComponent;
Class Operation extends SyntaxComponent;

And the subclass 'Rule' has an 'Operation' member value. And this gives the problems!

class Rule extends SyntaxComponent {
private Operation op;
...
}

I posted my mapping file below.

Code:

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC 
        "-//Hibernate/Hibernate Mapping DTD 2.0//EN"
        "http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">
<!-- @author Stijn Deroo-Van Maele -->
<!-- SyntaxComponent.hbm.xml -->
<!-- ORM mapping for 'SyntaxComponent' class -->

<hibernate-mapping>
    
    <class 
        name="syntaxtree.SyntaxComponent" 
        table="SYNTAX_COMPONENT">
        
        <id
            name="id"
            column="SYNTAX_COMPONENT_ID"
            type="long">
            <generator class="native"/>
        </id>        
 
        <property 
            name="name" 
            column="NAME" 
            not-null="false" 
            unique="false"
            type="string"/>

        <joined-subclass
         name="syntaxtree.Operation"
         table="OPERATION">
         <key column="id"/>  
         <property
             name="operatorType"
             column="OPERATOR_TYPE"
             type="string"
         />
            <joined-subclass
                name="syntaxtree.ComparisonOp"
                table="COMPARISON_OP">
                <key column="id"/>
            </joined-subclass>                             
      </joined-subclass>   
           
        <joined-subclass
         name="syntaxtree.Rule"
         table="RULE">
         <key column="id"/>
         <property
             name="active"
             column="ACTIVE"
             type="boolean"
         />
            <property
             name="description"
             column="DESCRIPTION"
             type="string"
         />   
         <property
             name="scope"
             column="SCOPE"
             type="int"
         />
         <property
             name="type"
             column="TYPE"
             type="int"
            />
            
            <many-to-one name="operation" class="syntaxtree.Operation" column="OPERATION_ID" unique="true"/>
            
            <!-- <one-to-one name="operation" class="syntaxtree.Operation" constrained="true"></one-to-one>-->
                        
      </joined-subclass>    
                                                                                
    </class> 
</hibernate-mapping>

[/code]

emmanuel · **Posted:** Mon Jan 10, 2005 10:39 am

Opration should be on the DB or somehow cascaded

sdroovan · **Posted:** Mon Jan 10, 2005 10:47 am

The problem was with the id. I declared it by mistake as long instead of Long.