Hi every body,
Look at these classes examples to see my problems with hibernate on jboss (for a mySql database) and understand what i want to do :

@Entity
@Table(name=Mother)
@Inheritance(strategy = InheritanceType.JOINED)
public class Mother implements Serializable{
@Id
private String mother_id;
public Mother(){}

//... getters/setters generated for all fields members
}

Note : The Mother table has a single primary key : its id



@Embeddable
public Class DaughterKey implements Serializable{
private String mother_Id;
private String daughter_id;
public DaughterKey(){}

//getters/setters generated for the both fields

// the methods : toString(),hasCode(),equals() are overrided
}

Note : the DaughterKey is a class that specifies (according to my understandings) a composite primary key class when mappings happen !



@Entity
@Table(name = "Daughter")
@IdClass(DaughterKey.class)
@PrimaryKeyJoinColumn(name = "Mother_id")
public class Daughter extends Mother{
@Id
private String daughter_id;
public Daughter(){ super();}

//.. getter/setter for all fields
}

Note: the Daughter table has a composite key (mother_Id+daughter_id).




So,the idea is that eventhough a Daughter Class extends a Mother Class, the Daughter must have 2 fields-members as PrimaryKey in the Database (the mother_id and its own daughter_id) : a composite key.

After compiling and creating a JAR file, I try to deploy the JAR-file and i have a such exception :

java.lang.reflect.InvocationTargetException
//.... at ....
caused by

org.hibernate.AnnotationException : Unable to define/override @Id(s) on a subclass : Daughter.

Thanks a lot if someOne can help me, I know that it's because my conception is not correct but I can't get any better ided.


PS : Ask your questions, if you don't understand my idea !
Best regards, Divx.

Mother_id has to be unique itself, because in a joined inheritance every instance of the subclass has a row even in the "mother" table.
If mother_id is unique, why bother to declare daughter_id part of the primary key?
Just map it as a property.