Hibernate version3.0alpha:

Mapping documents:

<hibernate-mapping package="com.matt">
<class name="Field" table="fc_fields" >
<composite-id name="FieldId" class="FieldId">
<key-property name="fcId" column="fc_id" type="int" />
<key-many-to-one name="fldId" column="fld_id" type="int" />
</composite-id>

<property name="name" column="fld_name" type="string"/>
<property name="description" column="fld_desc" type="string"/>
<property name="colName" column="col_name" type="string"/> <property name="colType" column="col_type" type="java.lang.Character"/>
<property name="tableName" column="tbl_name" type="string"/>
</class>

</hibernate-mapping>





I'm not sure I fully understand the meaning of the <key-many-to-one /> tag. In this table there are two primary keys: fc_id and fld_id. Their combinations look like the following:

fc_id fld_id
1 1
1 2
1 3
2 1
2 2
3 1
3 2
3 3
3 4


Am I mapping this correctly based on this information? And how do composite ids correctly generate new ids on inserts? I would definitely set the fc_id, but the fld_id should just increment. Any help would be appreciated.

Composite id's are newer generated automatically you have to assign them yourself. But you can create a ComopsiteUserType and use the id tag, additionaly you have to write your own IdGenerator to get automatic id assignment.

Anybody else can help with the <key-many-to-one /> question.

HTH
Ernst