InheritanceType.TABLE_PER_CLASS question

[pimpf]

Because the EJB3.0 FD spec doesn't say to much about that kind of inheritance strategy, I looked up at the following examples:
[url]http://docs.jboss.org/ejb3/app-server/tutorial/tableperinheritance/table.html[/url]

I played with them but an exception occured:
javax.ejb.EJBException: org.hibernate.exception.SQLGrammarException: could not execute query
at org.jboss.ejb3.tx.Ejb3TxPolicy.handleExceptionInOurTx(Ejb3TxPolicy.java:69)
at org.jboss.aspects.tx.TxPolicy.invokeInOurTx(TxPolicy.java:83)
*****
Caused by: org.hibernate.exception.SQLGrammarException: could not execute query
at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:65)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)
at org.hibernate.loader.Loader.doList(Loader.java:2148)
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2029)
at org.hibernate.loader.Loader.list(Loader.java:2024)
at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:375)
at org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:308)
at org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:153)
at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1129)
at org.hibernate.impl.QueryImpl.list(QueryImpl.java:79)
at org.hibernate.ejb.QueryImpl.getResultList(QueryImpl.java:39)
****
Caused by: java.sql.SQLException: ORA-00942: table or view does not exist

I have the following class definition:

@Entity
@Inheritance(strategy = InheritanceType.TABLE_PER_CLASS)
public class Pet implements java.io.Serializable {
private int id;

private String name;

private int weight;
*****
-----------------------------------------

@Entity
@Table(name="CAT")
public class Cat extends Pet
{
int lives;

public int getLives()
{
return lives;
}

public void setLives(int lives)
{
this.lives = lives;
}
}
---------------------------------------------

@Entity
@Table(name="DOG")
public class Dog extends Pet
{
private int numBones;

public int getNumBones()
{
return numBones;
}

public void setNumBones(int numBones)
{
this.numBones = numBones;
}
}

and a stateless session bean:
public List getAllPets( ){

return em.createQuery("from Pet p").getResultList();

}

************************

I have only two table - CAT and DOG exactly as provided in the example above.

Can anyone see where is the problem - should I have table PET?!?

[mwoelke]

maybe its because u dont have any properties defined for pet. Or didnt u just post them? Do cat and dog tables contain pet attributes?

Regards, Milan Wölke

[pimpf]

Here is the whole Pet class:

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Inheritance;
import javax.persistence.InheritanceType;

@Entity
@Inheritance(strategy = InheritanceType.TABLE_PER_CLASS)
public abstract class Pet implements java.io.Serializable {
private int id;

private String name;

private int weight;

@Id
@GeneratedValue(strategy = GenerationType.TABLE)
public int getId() {
return id;
}

public void setId(int id) {
this.id = id;
}

public String getName() {
return name;
}

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

public int getWeight() {
return weight;
}

public void setWeight(int weight) {
this.weight = weight;
}
}


Also here are the two tables:

create table CAT (
ID NUMBER primary key,
LIVES NUMBER,
NAME varchar2(20),
WEIGHT NUMBER
);

create table DOG (
ID NUMBER primary key,
NUMBONES NUMBER,
NAME varchar2(20),
WEIGHT NUMBER
);