I know I'm doing something stupid, but can't figure out what. Please help.

here's the parent's mapping:

and the child's mapping:

When I do this:


what I get is a new record in the employee table, but no new record in the appointment table.

Now, if I go into Appointment.hbm.xml and change <id> from foreign to native, then an appointment record does get inserted, but the primary key value is not, obviously, syncrhoized with the parent's primary key.

What am I doing wrong?


Hibernate version:
2.1.3

Mapping documents:
see above

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

Full stack trace of any exception that occurs:
n/a

Name and version of the database you are using:
mysql 3.1.xx

The generated SQL (show_sql=true):
see below

Debug level Hibernate log excerpt:
...
[main] DEBUG net.sf.hibernate.impl.SessionFactoryImpl - instantiated session factory
Hibernate factory inited
[main] DEBUG net.sf.hibernate.impl.SessionImpl - opened session
Openning Hibernate session net.sf.hibernate.impl.SessionImpl@1e7c5cb
[main] DEBUG net.sf.hibernate.impl.SessionImpl - saveOrUpdate() unsaved instance
[main] DEBUG net.sf.hibernate.impl.SessionImpl - saving [edu.ucsd.som.salpro.model.SalProEmployee#<null>]
[main] DEBUG net.sf.hibernate.impl.SessionImpl - executing insertions
[main] DEBUG net.sf.hibernate.engine.Cascades - processing cascades for: edu.ucsd.som.salpro.model.SalProEmployee
[main] DEBUG net.sf.hibernate.engine.Cascades - done processing cascades for: edu.ucsd.som.salpro.model.SalProEmployee
[main] DEBUG net.sf.hibernate.impl.WrapVisitor - Wrapped collection in role: edu.ucsd.som.salpro.model.SalProEmployee.divisions
[main] DEBUG net.sf.hibernate.engine.Cascades - id unsaved-value strategy NULL
[main] DEBUG net.sf.hibernate.persister.EntityPersister - Inserting entity: edu.ucsd.som.salpro.model.SalProEmployee (native id)
[main] DEBUG net.sf.hibernate.impl.BatcherImpl - about to open: 0 open PreparedStatements, 0 open ResultSets
[main] DEBUG net.sf.hibernate.SQL - insert into salpro_employee (full_name, ucsd_id, home_department_id) values (?, ?, ?)
[main] DEBUG net.sf.hibernate.impl.BatcherImpl - preparing statement
[main] DEBUG net.sf.hibernate.persister.EntityPersister - Dehydrating entity: [edu.ucsd.som.salpro.model.SalProEmployee#<null>]
[main] DEBUG net.sf.hibernate.type.StringType - binding 'Jonny Smith' to parameter: 1
[main] DEBUG net.sf.hibernate.type.StringType - binding null to parameter: 2
[main] DEBUG net.sf.hibernate.engine.Cascades - id unsaved-value strategy NULL
[main] DEBUG net.sf.hibernate.type.StringType - binding '34' to parameter: 3
[main] DEBUG net.sf.hibernate.persister.AbstractEntityPersister - Natively generated identity: 2
[main] DEBUG net.sf.hibernate.impl.BatcherImpl - done closing: 0 open PreparedStatements, 0 open ResultSets
[main] DEBUG net.sf.hibernate.impl.BatcherImpl - closing statement
[main] DEBUG net.sf.hibernate.engine.Cascades - processing cascades for: edu.ucsd.som.salpro.model.SalProEmployee
[main] DEBUG net.sf.hibernate.engine.Cascades - cascading to saveOrUpdate()
[main] DEBUG net.sf.hibernate.impl.SessionImpl - saveOrUpdate() unsaved instance
[main] DEBUG net.sf.hibernate.impl.SessionImpl - generated identifier: 2
[main] DEBUG net.sf.hibernate.impl.SessionImpl - saving [edu.ucsd.som.salpro.model.Appointment#2]
[main] DEBUG net.sf.hibernate.engine.Cascades - done processing cascades for: edu.ucsd.som.salpro.model.SalProEmployee

Hi, I think the problem may be becasue you are saving the Appointment which has no cascade set, so it will not save the Employee. Try saving the Employee, or adding a cascade to the Appointment mapping.

HTH

Paul :-)

Doh! You're right. But this doesn't change anything. That code was just a simplyfied version of the real code (which has correct logic). Here's a corrected version:



the end result is the same as before: a new Employee record is created in the employee table, but no appointment record is created in the appointment table.

A bigger question is: what conditions may prevent appointment data from getting persisted? (keeping in mind that no exceptions are thrown and the debug trace contains no errors/warnings)

Hi looking at the example in Hibernate in Action (if you have the book, it's page 220 onwards, if you don't & you're serious about Hibernate, then you need it!), you need to map one end of the relationship with a many-to-one mapping with a unique="true" attribute!! Yes weird & counter-intuitive, but that's how it seems to work.

You'll have to work out which end of the relationship you want to map as many-to-one (I'm not sure if it matters), but for example yours could look like this.





This would give you a bi-directional relationship.

Give this a try
Paul :-)

Oops, just looked again & realized that you are using primary-Key mapping not foreign-key mapping!! Sorry :-)

I think the problem is the generator class in your employee. It shouldn't be native, but should be


HTH
Paul

Paul, but the employee's id is not a foreign key, it's the table's primary key. Now, i agree that the appointment's id is a foreign key into the employee table, and that's how I have these two mapped.

Oops sorry again! Late night posting isn't good, I didn't notice that you had commented out the "native" line & added a foreign generator underneath.

Are you sure no appointment record is being persisted to the database
this line
[main] DEBUG net.sf.hibernate.impl.SessionImpl - saving [edu.ucsd.som.salpro.model.Appointment#2] would appear to indicate that an appointment record is being saved??

Also can you show the code for your PersistentObject.save() method.

Paul :-)

This is the most puzzling part of the problem. Yes, i've checked over and over :) and nothing is being saved. I'm using DBUnit for testing, so it's easy to see when anything is being created. At the moment the table is emply.

Also, i have show_sql enabed and I can see in the trace the sql statement used for inserting a new employee record.



Yet, an sql statement for inserting an appointment is conspicuously missing from the trace. Which tells me that Hibernate never actually generates and sends a query to the database. Weird. WHy?

Here's the code for the save() method:



this function is used through out multiple production applications and i've not had any problems with it.

Dmitry

PS. Thanks for your help so far, Paul

Have you tried using unsaved value?? Try the following..hope this helps.
(Parent mapping)
<id name="id" column="salpro_employee_id" type="long" unsaved-value="null">


(Child mapping)
<id name="_id" column="appointment_id" type="long" unsaved-value="null">

"unsaved-value" is null by default. this isn't it :(

Are you closing the sesion anywhere? Your method doesn't seem to do this (maybe as you've only shown part of the code). I think that you should close the session, but the problem may be that as you are not using transactions (why not?), you probably need to call session.flush() before closing the session.

Paul :-)