Hi all,

I try to use Hibernate 3.0.5 to map inherited class with the method describled in the document "10.1.5. Table per concrete class". However, Hibernate always creates a table for my parent abstract class. Here is my sampe java code and mapping xml:

[code]
public abstract class Property {
protected long propertyId;
protected String name;

public long getPropertyId() {
return propertyId;
}

public void setPropertyId(long propertyId) {
this.propertyId = propertyId;
}

public String getName() {
return name;
}

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

abstract Object getPropertyValue();
}

public class StringProperty extends Property {
String value;

Object getPropertyValue() {
return value;
}
}

public class DateProperty extends Property {
Date value;

Object getPropertyValue() {
return value;
}
}

<class name="Property">
<id name="propertyId" column="property_id" unsaved-value="0">
<generator class="increment"/>
</id>
<property name="name" column="name" type="string" />

<union-subclass name="StringProperty" table="string_property">
<property name="value" column="value" type="string" />
</union-subclass>

<union-subclass name="DateProperty" table="date_property">
<property name="value" column="value" type="date" />
</union-subclass>
</class>

[/code]

Hibernate generates the following result:

create table Property (
property_id bigint not null,
name varchar(255),
primary key (property_id)
);

create table date_property (
property_id bigint not null,
name varchar(255),
value date,
primary key (property_id)
);

create table string_property (
property_id bigint not null,
name varchar(255),
value varchar(255),
primary key (property_id)
);


According to the docuemntation, it should have only 2 tables. Has anyone any idea? Thanks in advance!

You have three concrete classes, you can make a class abstract="true"