Hello, I'm having a big problem with hibernate I can't seem to solve.
I have 2 java classes :
CMinimalProfile and CProfile. CProfile extends CMinimalProfile

CMinimalProfile only contrains the id of the profile whereas CProfile contains a ton of information. I don't want to send the full profile to the client when only the ID is needed.

In my database I only have one table tprofile

I made two mapping files, one for each class.
cminimalprofile.hbm.xml :
<?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 default-lazy="false">
<class name="profile.CMinimalProfile" table="tprofile" >
<id name="id" type="int" column="id_profile">
<generator class="increment" />
</id>
</class>
</hibernate-mapping>


cprofile.hbm.xml :
<?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 default-lazy="false">
<class
name="profile.CProfile"
table="tprofile" >

<id name="id" type="int" column="id_profile">
<generator class="increment" />
</id>

<property name="name">
<column name="name" />
</property>

... a bunch of properties ...
</class>

the mapping seems to work, but when I try to query CMinimalProfiles here is what happens :

Say I have 2 profiles in my table tprofiles.

=> session.createQuery("from CMinimalProfile").list()

I would like this to return a list with two CMinimalProfiles with their id filled up.
BUT for some reason i fail to understand, the list does not contain 2 items but FOUR.

I get the 2 CMinimalProfiles I wanted, but I also have 2 extra objects of class CProfile in the list.

I don't understand why it happens...

I tried to use hibernate inheritance mechanisms but it didn't work either, I tried to implement inheritance in my database too but it doesn't work because PostgreSQL inheritance seem to have problems with foreign keys and subtables but this is an other issue I guess.

Anyway, can someone explain why with the above exemple, hibernate returns a list of 4 objects instead of just two ?

Thank you for your answers.

This is called implicit polymorphism, and is described in the documentation http://docs.jboss.org/hibernate/stable/ ... lymorphism

It can be disabled for a class by mapping it with:



Here is an example: http://docs.jboss.org/hibernate/stable/ ... tion-class

Can we create implicit poly morphism relationship while reverse engineering through hibernate tools? Moreover, do we have any nice example for implementing implicit polymorphism using annotations.