Is there any way to define a composite candidate key in a mapping association? I have two tables:

table 1:

id

properties-
candidatekey1
candidatekey2
table1name, etc

table 2:

somecompositeid

properties-
candidatekey1
candidatekey2
table2value, etc

I would like to define a one-to-many set by candidatekey1.
<set name="transactionCustomer" inverse="true" lazy="true">
<key>
<column name="key1"/>
<column name="key2"/>
</key>
<one-to-many class="com.xxx.TransactionCustomer" />
</set>

I realize this is not designed very well but it is what I have to work with and the transaction customer file is extremely large so adding table1.id is not practical right now.