I have 2 tables that use the same primary key to link each other on a one-to-one basis.

Can someone point me to an example of such a situation that includes what the Java class files look like and the mapping files. I've found a lot of examples, but they tend to show just the mapping file and I don't know how my properties should be configured.

Alternatively, can you tell me how the following should be done:

The tables are as follows:



MYSESSION
=======
sessionId VARCHAR(32) PK
description VARCHAR(255)


INBOUND_SESSION
===============
sessionId VARCHAR(32) PK
startTime TIMESTAMP



for the inbound session, I'm not sure if the class should look like this (I left off the setters and getters for readability:

public class InboundSession {
private String sessionId ; // Use the session ID
private Date timestamp ;
}

or like this:

public class InboundSession {
private MySession session ; / Use a MySession
private Date timestamp ;
}



I'm pretty sure MySession should look like this:

public class MySession {
private String sessionId ;
private String description ;
private InboundSession inboundSession ;
}

Even though it's a one-to-one relationship, I want the sessionId to be a uuid generator on the MySession object and then that sessionId to be used for the InboundSession object.

I've tried various combinations and settings and I get one of two possible errors:

- Hibernate can't process the hbm.xml file
- I get an error about assigning a null id in a one-to-one mapping

The field representing a one-to-one (or any entity association) should always be an object, not a value. So InboundSession.getMySession() needs to return a MySession object, not MySession's id. InboundSession will have an id field, but you should probably not include getId or setId in its interface (though hibernate needs the methods, so they should be in the implementing class).

MySession will have a getSessionId() (returns String) and a getInboundSession() (returns an InboundSession object).

The id generator on InboundSession should be class="foreign". Everything else is pretty standard, nothing special needs to be done.

Thanks for clarifying this. It was the exact info I needed to get over the hurdle.

Hi, I have the same problem and I am struggling with how the above example can be done with xdoclet tags.

My example is similar to the MySession one except the id fields are java.lang.Long fields.
I am guessing that the xdoclet tags in MySession would look like this:


and in InboundSession:


However, when I create the hibernate mapping files, I come up with an InboundSession table that has a composite id made up of all the fields in the MySession table, which is not what I want.

Can anyone help me?

Never mind, I got it. If anyone is interested, the mapping in the Inbound Session is like this: