Mixing xref:inheritanceonetableperclass2 and xref:inheritancesingletable I just want to mention that mixing these two approaches is possible.

    <subclass name="Flower" discriminator-value="flower">
    <property name="color" type="string"></property>
    </subclass>
    <subclass name="HardrockGroup" discriminator-value="hardrock">
      <join table="thardrock">
        <key column="musicgroup_id"></key>
        <property name="destroyedGuitars" type="integer" not-null="true"/>
      </join>
    </subclass>