package org.hibernate.test.collection.list;

import java.util.List;
import java.util.ArrayList;

/**
* {@inheritDoc}
*
* @author Steve Ebersole
*/

public class ListOwner {

   private String name;
   private ListOwner parent;
   private List children = new ArrayList();

   public ListOwner() {
   }

   public ListOwner(String name) {
      this.name = name;
   }

   public String getName() {
      return name;
   }

   public void setName(String name) {
      this.name = name;
   }

   public ListOwner getParent() {
      return parent;
   }

   public void setParent(ListOwner parent) {
      this.parent = parent;
   }

   public List getChildren() {
      return children;
   }

   public void setChildren(List children) {
      this.children = children;
   }

}

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
   "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
   "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping package="org.hibernate.test.collection.list">
    <class name="ListOwner">
      <id name="name" column="NAME" type="string" />
        <many-to-one name="parent" class="ListOwner" cascade="none" update="false" insert="false" />
        <list name="children"  cascade="all, delete-orphan" table="listowners">       
            <key column="PARENT" />
            <list-index column="LIST_INDEX"/>
            <many-to-many class="ListOwner" unique="true" />
        </list>
   </class>
</hibernate-mapping>

package org.hibernate.test.collection.list;

import java.util.ArrayList;
import junit.framework.Test;
import org.hibernate.Session;
import org.hibernate.collection.PersistentList;
import org.hibernate.junit.functional.FunctionalTestCase;
import org.hibernate.junit.functional.FunctionalTestClassTestSuite;


/**
* Tests related to operations on a PersistentList
*
* @author Steve Ebersole
*/

public class PersistentListTest extends FunctionalTestCase {

   public PersistentListTest(String name) {
      super( name );
   }

   public String[] getMappings() {
      return new String[] { "collection/list/Mappings.hbm.xml" };
   }

   public static Test suite() {
      return new FunctionalTestClassTestSuite( PersistentListTest.class );
   }

   public void testRandomRemove() {

      ListOwner parent = new ListOwner( "root" );
      ListOwner child = new ListOwner( "c1" );
      ListOwner child1 = new ListOwner( "c2" );
      ListOwner child2 = new ListOwner( "c3" );
      ListOwner child3 = new ListOwner( "c4" );
      parent.getChildren().add( child );
      parent.getChildren().add( child1 );
      parent.getChildren().add( child2 );
      parent.getChildren().add( child3 );
      child.setParent( parent );
      child1.setParent( parent );
      child2.setParent( parent );


      Session session = openSession();
      session.beginTransaction();
      session.save( parent );
      session.flush();

      parent.getChildren().remove( 1 );
      session.update( parent );
      session.flush();
      session.getTransaction().commit();
      session.close();            

   }
}

Hibernate:
    delete
    from
        listowners
    where
        PARENT=?
        and LIST_INDEX=?
Hibernate:
    update
        listowners
    set
        elt=?
    where
        PARENT=?
        and LIST_INDEX=?
14:08:41,470  WARN JDBCExceptionReporter:77 - SQL Error: 0, SQLState: null
14:08:41,470 ERROR JDBCExceptionReporter:78 - Batch entry 0 update listowners set elt=c3 where PARENT=root and LIST_INDEX=1 was aborted.  Call getNextException to see the cause.
14:08:41,470  WARN JDBCExceptionReporter:77 - SQL Error: 0, SQLState: 23505
14:08:41,470 ERROR JDBCExceptionReporter:78 - ERROR: duplicate key violates unique constraint "listowners_elt_key"
14:08:41,477 ERROR AbstractFlushingEventListener:301 - Could not synchronize database state with session
org.hibernate.exception.ConstraintViolationException: Could not execute JDBC batch update
   at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:71)
   at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)
   at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:253)
   at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:237)
   at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:144)
   at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:298)
   at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:27)
   at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1000)
   at org.hibernate.test.collection.list.PersistentListTest.testRandomRemove(PersistentListTest.java:93)
   at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
   at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
   at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
   at java.lang.reflect.Method.invoke(Method.java:597)
   at junit.framework.TestCase.runTest(TestCase.java:154)
   at org.hibernate.junit.functional.FunctionalTestCase.runTest(FunctionalTestCase.java:101)
   at junit.framework.TestCase.runBare(TestCase.java:127)
   at org.hibernate.junit.UnitTestCase.runBare(UnitTestCase.java:34)
   at junit.framework.TestResult$1.protect(TestResult.java:106)
   at junit.framework.TestResult.runProtected(TestResult.java:124)
   at junit.framework.TestResult.run(TestResult.java:109)
   at junit.framework.TestCase.run(TestCase.java:118)
   at junit.framework.TestSuite.runTest(TestSuite.java:208)
   at org.hibernate.junit.functional.FunctionalTestClassTestSuite.runTest(FunctionalTestClassTestSuite.java:100)
   at junit.framework.TestSuite.run(TestSuite.java:203)
   at org.hibernate.junit.functional.FunctionalTestClassTestSuite.run(FunctionalTestClassTestSuite.java:69)
   at org.eclipse.jdt.internal.junit.runner.junit3.JUnit3TestReference.run(JUnit3TestReference.java:128)
   at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
   at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:460)
   at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:673)
   at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:386)
   at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:196)
Caused by: java.sql.BatchUpdateException: Batch entry 0 update listowners set elt=c3 where PARENT=root and LIST_INDEX=1 was aborted.  Call getNextException to see the cause.
   at org.postgresql.jdbc2.AbstractJdbc2Statement$BatchResultHandler.handleError(AbstractJdbc2Statement.java:2497)
   at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1299)
   at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:349)
   at org.postgresql.jdbc2.AbstractJdbc2Statement.executeBatch(AbstractJdbc2Statement.java:2559)
   at com.p6spy.engine.logging.P6LogPreparedStatement.executeBatch(P6LogPreparedStatement.java:329)
   at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:48)
   at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:246)
   ... 28 more