Hi All,

I need some help to write my hbm file ,the scenario will be as below:

I have a super class 'A' and subclasses B , C and the Java classes will be as follows:

public abstract class Z{
private String classCode;
//Setter and getter methods
}

public class A extends Z{
private String city;
private String state;
private String name;
//Setter and getter methods

}

public class B extends A{
private String email;
//Setter and getter methods
}

public class C extends A{
private String temp;
//Setter and getter methods
}

Now i have a hibernate mapping file as follows:

<hibernate-mapping>
<class name="A" table="a" abstract="true" proxy="A">
<id name="id" unsaved-value="0">
<generator class="native" />
</id>
<discriminator column="class_code" type="string"/>
<property name="classCode" column="class_code" type="string" insert="false" update="false" />
<property name="name" type="string" column="name" />
<property name="city" type="string" column="city" />
<property name="state" type="string" column="state" />

<subclass name="A" discriminator-value="a" proxy="A">
<property name="email" type="string" column="email" />
</subclass>

<subclass name="B" discriminator-value="b" proxy="B">
<property name="temp" type="string" column="temp" />
</subclass>
</class>
</hibernate-mapping>



Now i want to introduce one more class D which will be something like this :

public class D extends Z{
private String name;
private String description;
private long mappingId;
}
and has a table for this object with primary key 'id' ;

Now i want to have list of Ds for B , C;

so the classes will be modified something like below:

public class B extends A{
private String email;
private List<D> = new ArrayList<D>();
//Setter and getter methods
}

public class C extends A{
private String temp;
private List<D> = new ArrayList<D>();
//Setter and getter methods
}


Now i want have a database design as below:

I should have only one table for 'D' and one table for each Class which will have this D as a list.(for example the classes B and C).Now i have to map these tables as below:

I will have two columns class_code and mapping_id for table 'D' and want to access the rows from this table using the combination of these two fields as a composite key.

Note :-- I don't want to have any extra mapping tables for this mapping .But i want to retrieve the data from table 'D' by using the combination of class_code and mapping_id as a composite key.

Then how can i map this scenario in the given hbm file ? Please help me to solve this.

Thanks in advance
Raj