Hello,

I have posted this in ther german forum but there comes no reply -- so i give it here another try . . .

I am working with Hibernate-Annotations and after some smaller problems i got further and further ;-)

But there is a bigger problem i couldnt solve yet. There is a inheritence structure I could not set in annotations yet.
I have got some classes:



SMS and Email are extended AbstractAdHocNews which should be mapped within a SINGLE_TABLE called AdHocNews. Furthermore, AbstractAdHocNews and News should be in two different tables. So I marked the inheritence strategy of News with TABLE_PER_CLASS. But there should remain a reference of all AbstractNews in the table News. I tried to use @MappedSuperClass: This created two tables as I want, but all attributes of the superclass News were in the AbstractAdHocNews table as well. I want it like this:



"discr" is the discriminator value, e.g. "sms" or "email".

My result for now is that I have got no AbstractAdHocNews table. I get a SMS table and a Email table. Isnt it possible to override inheritence strategys?

My Mapping Annotation Signatures are as the following

## News ##

@Entity
@Inheritance(strategy = InheritanceType.TABLE_PER_CLASS)
public class News implements Serializable {
. . .
}

## AbstractAdHocNews ##

@Entity
@Inheritance(strategy=InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn(name="NEWS_TYPE",discriminatorType=DiscriminatorType.STRING)
public abstract class AbstractAdhocNews extends News {
. . .
}

## SmsNews ##

@Entity
@DiscriminatorValue("SMS_NEWS")
public class SmsNews extends AbstractAdhocNews {
. . .
}

## EmailNews ##

@Entity
@DiscriminatorValue("EMAIL_NEWS")

Thanks for your help

Henning
[/b]

Reference says (2.2.4):

@Inheritance and @DiscriminatorColumn should only be defined at the top of the entity hierarchy.

so well, top of the entity . . .

somewhere else (deeper at the end):

(7) inheritance: defines the inheritance strategy (JOINED, TABLE_PER_CLASS, SINGLE_TABLE), Available only at the root entity level

aaaaaaaaaah, the root level of the inheritence!


The next time when I try something out, I´ll search the whole reference for the keyword . . .

I hope this saves some time for others who didn´t get that point, too.

so long

Henning