I have two tables in a master/detail configuration pm_project_revision and pm_task. In my classes ProjectRevisionTo has an array list of tasks. I want to use an order list for the tasks. When I save the revision the index column in the pm_task table is not saved. So when I try to obtain the revision I get null index column for collection.

Hibernate version: 3.1.3

Mapping documents:
<?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>
<class name="ve.com.tcs.pm.to.ProjectRevisionTo" table="pm_project_revision" lazy="false">
<id name="id" column="id" type="long" unsaved-value="0">
<generator class="sequence">
<param name="sequence">pm_sequence</param>
</generator>
</id>
<property name="revision" column="revision" type="long"/>
<property name="author" column="author" type="string"/>
<property name="startDate" column="start_date" type="timestamp"/>
<property name="endDate" column="end_date" type="timestamp"/>
<property name="duration" column="duration" type="double"/>
<property name="actualStartDate" column="actual_start_date" type="timestamp"/>
<property name="actualEndDate" column="actual_end_date" type="timestamp"/>
<property name="actualDuration" column="actual_duration" type="double"/>
<property name="latest" column="latest" type="yes_no"/>
<many-to-one name="project" column="project_id" class="ve.com.tcs.pm.to.ProjectTo" cascade="save-update"/>
<list name="tasks" table="pm_task" lazy="true" cascade="all-delete-orphan" inverse="true">
<key column="project_revision_id"/>
<index column="order_seq"/>
<one-to-many class="ve.com.tcs.pm.to.TaskTo"/>
</list>
</class>
</hibernate-mapping>

<hibernate-mapping>
<class name="ve.com.tcs.pm.to.TaskTo" table="pm_task" lazy="false">
<id name="id" column="id" type="long" unsaved-value="0">
<generator class="sequence">
<param name="sequence">pm_sequence</param>
</generator>
</id>
<property name="name" column="name" type="string"/>
<property name="startDate" column="start_date" type="timestamp"/>
<property name="endDate" column="end_date" type="timestamp"/>
<property name="duration" column="duration" type="double"/>
<property name="actualStartDate" column="actual_start_date" type="timestamp"/>
<property name="actualEndDate" column="actual_end_date" type="timestamp"/>
<property name="actualDuration" column="actual_duration" type="double"/>
<property name="actualCost" column="actual_cost" type="double"/>
<property name="plannedValue" column="planned_value" type="double"/>
<property name="earnedValue" column="earned_value" type="double"/>
<many-to-one name="revision" column="project_revision_id" class="ve.com.tcs.pm.to.ProjectRevisionTo"/>
<many-to-one name="parent" column="parent_id" class="ve.com.tcs.pm.to.TaskTo"/>
<bag name="children" table="pm_task" lazy="true" cascade="all-delete-orphan" inverse="true">
<key column="parent_id"/>
<!-- index column="order_seq"/ -->
<one-to-many class="ve.com.tcs.pm.to.TaskTo"/>
</bag>
<list name="predecessors" table="pm_task_dependency" lazy="true" cascade="all-delete-orphan">
<key column="successor_task_id"/>
<index column="order_seq"/>
<many-to-many class="ve.com.tcs.pm.to.TaskTo" column="predecessor_task_id"/>
</list>
<list name="successors" table="pm_task_dependency" lazy="true" cascade="none">
<key column="predecessor_task_id"/>
<index column="order_seq"/>
<many-to-many class="ve.com.tcs.pm.to.TaskTo" column="successor_task_id"/>
</list>
</class>
</hibernate-mapping>

Code between sessionFactory.openSession() and session.close():

revision = (ProjectRevisionTo) session.createQuery ("from ProjectRevisionTo where id = ?").setLong (0, id).uniqueResult ();
if (revision != null)
{
Hibernate.initialize (revision.getTasks ());

iterator = revision.getTasks ().iterator ();
while (iterator.hasNext ())
{
task = (TaskTo) iterator.next ();

Hibernate.initialize (task.getChildren ());
}
}

Full stack trace of any exception that occurs:

rg.hibernate.HibernateException: null index column for collection: ve.com.tcs.pm.to.ProjectRevisionTo.tasks

at org.hibernate.persister.collection.AbstractCollectionPersister.readIndex(AbstractCollectionPersister.java:652)

at org.hibernate.collection.PersistentList.readFrom(PersistentList.java:358)

at org.hibernate.loader.Loader.readCollectionElement(Loader.java:994)

at org.hibernate.loader.Loader.readCollectionElements(Loader.java:635)

at org.hibernate.loader.Loader.getRowFromResultSet(Loader.java:580)

at org.hibernate.loader.Loader.doQuery(Loader.java:689)

at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:224)

at org.hibernate.loader.Loader.loadCollection(Loader.java:1919)

at org.hibernate.loader.collection.CollectionLoader.initialize(CollectionLoader.java:36)

at org.hibernate.persister.collection.AbstractCollectionPersister.initialize(AbstractCollectionPersister.java:521)

at org.hibernate.event.def.DefaultInitializeCollectionEventListener.onInitializeCollection(DefaultInitializeCollectionEventListener.java:60)

at org.hibernate.impl.SessionImpl.initializeCollection(SessionImpl.java:1676)

at org.hibernate.collection.AbstractPersistentCollection.forceInitialization(AbstractPersistentCollection.java:454)

at org.hibernate.Hibernate.initialize(Hibernate.java:295)

at ve.com.tcs.pm.bf.ProjectManagementBf.getProjectRevision(ProjectManagementBf.java:926)

Name and version of the database you are using:

Oracle10g Release 2

The generated SQL (show_sql=true):

Hibernate: select tasks0_.project_revision_id as project12_2_, tasks0_.id as id2_, tasks0_.order_seq as order14_2_, tasks0_.id as id11_1_, tasks0_.name as name11_1_, tasks0_.start_date as start3_11_1_, tasks0_.end_date as end4_11_1_, tasks0_.duration as duration11_1_, tasks0_.actual_start_date as actual6_11_1_, tasks0_.actual_end_date as actual7_11_1_, tasks0_.actual_duration as actual8_11_1_, tasks0_.actual_cost as actual9_11_1_, tasks0_.planned_value as planned10_11_1_, tasks0_.earned_value as earned11_11_1_, tasks0_.project_revision_id as project12_11_1_, tasks0_.parent_id as parent13_11_1_, taskto1_.id as id11_0_, taskto1_.name as name11_0_, taskto1_.start_date as start3_11_0_, taskto1_.end_date as end4_11_0_, taskto1_.duration as duration11_0_, taskto1_.actual_start_date as actual6_11_0_, taskto1_.actual_end_date as actual7_11_0_, taskto1_.actual_duration as actual8_11_0_, taskto1_.actual_cost as actual9_11_0_, taskto1_.planned_value as planned10_11_0_, taskto1_.earned_value as earned11_11_0_, taskto1_.project_revision_id as project12_11_0_, taskto1_.parent_id as parent13_11_0_ from pm_task tasks0_, pm_task taskto1_ where tasks0_.parent_id=taskto1_.id(+) and tasks0_.project_revision_id=?

I don't know if either of these are causing your problem, but maybe they're a good place to start:

1. cascade="delete-orphan" and inverse="true" is not a good combination of attrbiutes. delete-orphan means "parent object dictates lifecycle to child", and inverse="true" means "parent does not dictate lifecycle to child". A confusing mix, to be sure...
2. one-to-many probably doesn't fit with <list table="???">. I've certainly never seen that, and I don't know what it will do. If you specify a table attrbiute in a collection element, you usually (exclusively?) pair it with either a many-to-many or an <element> element. If you want a one-to-many with join table, the usual syntax is many-to-many unique="true".

Perhaps changing your mapping to eliminate those two oddities will fix your problem.