<hibernate-mapping>
    <class name="Activity" table="activity">
        <id name="id" type="string">
            <column name="id" length="32" />
            <generator class="assigned" />
        </id>
       
        <version name="version" type="int">
            <column name="version" not-null="true" />
        </version>
        <many-to-one name="login" class="Login" column="login_id" ></many-to-one>
        <property name="timeOn" type="int">
            <column name="time_on" not-null="true" />
        </property>
        <property name="activityType" type="string">
            <column name="activity_type" length="10" />
        </property>
        <property name="status" type="string">
            <column name="status" length="10" />
        </property>
        <property name="startTime" type="timestamp">
            <column name="start_time" length="0" />
        </property>
        <many-to-one name="game" class="
GamePerformance" column="game_id" ></many-to-one>

        <property name="lessonComplete" type="java.lang.Boolean">
            <column name="lesson_complete" />
        </property>
        <property name="exportStudentId" type="string">
            <column name="export_student_id" length="32" not-null="true" />
        </property>
       
        <joined-subclass  name="MasteryPerformance" table="mastery_performance">      
         <key column="id" foreign-key="activity_id"/>
         <version name="version" type="int">
            <column name="version" not-null="true" />
         </version>
         <property name="progress" type="byte">
            <column name="progress" not-null="true" />
         </property>
         <property name="exportStudentId" type="string">
            <column name="export_student_id" length="32" not-null="true" />
         </property>
       </joined-subclass>
    </class>