one-to-many mapping with table having no primay key

[Ankit Chandrawat]

Hi,

I have two tables:

Table1 {
primary key: ID_CHAT_SESSION
}

Table2 {
 ID_CHAT_SESSION
ID_USER
}

none of the columns in Table2 is primary key. How do I establish a one-to-many relationship between table1(id_chat_Session) and Table2.I have read that, using composite key can be an option. I can make both the columns as composite key of the table. But how do I map the column id_Chat_session in table1 and table2(id_chat_Session,id_user).

[Ankit Chandrawat]

create table QA_TEST3
(ID_CHAT_SESSION number not null,
ID_USER varchar2(40) not null,
primary key(ID_CHAT_SESSION,ID_USER));

<class name="com.mercer.chat.app.dataobject.MHRContChatSessionDO" 		
		table="QA_TEST2">
---

<set name="chatAlerts" batch-size="5" table="QA_TEST3" cascade="all"
				lazy="true">
				<cache usage="read-only" include="all" />
				<key column="ID_CHAT_SESSION" />
				<one-to-many
					class="com.mercer.chat.app.dataobject.MHRContChatAlertsDO" />
			</set>


</class>

<class name="com.mercer.chat.app.dataobject.MHRContChatAlertsDO" table="QA_TEST3"
		batch-size="2">
		<cache usage="read-only" include="all" />	 
		<composite-id >
	 	<key-property name="id" type="java.lang.Long">
				<column name="ID_CHAT_SESSION" />
			</key-property>
        
        <key-property name="userId" type="string">
				<column name="ID_USER" />
		</key-property>
		</composite-id>
			</class>



code Inside MHRContChatSessionDO.java

private Set<MHRContChatAlertsDO> chatAlerts = new HashSet<MHRContChatAlertsDO>(0);

Is there anything else that needs to be done as the I am not being able to fetch the object ?