I've seen this foriegn key error reported in the forums, but I have not seen a solution.

Basically, I have a parent with three columns that make up the primary key. A child table has a foreign key to the parent that is made up of two of the three keys. I would like a list of child items in the parent class based on a where something to the effect of parent.PK_1 = child.PK_1 and parent.PK_2 = child.PK_2.

However with the below mappings, I get org.hibernate.MappingException: Foreign key (FK33B30AA281A558:child [PK_1,PK_2])) must have same number of columns as the referenced primary key (MYPARENTTABLE [PK_1,PK_2,PK_3]).

Any help would truly be appreciated

Hibernate version:3.1.3
Mapping documents:
<hibernate-mapping>
<class name="MyParentClass" table="MYPARENTTABLE">
<composite-id name="id" class="MyParentClassId">
<key-property name="pk1" type="string" column="PK_1" />
<key-property name="pk2" type="string" column="PK_2" />
<key-property name="pk3" type="short" column="PK_3" />
</key-property>
</composite-id>
<property name="prop1" type="string" column="PROP_1" />
<property name="prop2" type="string" column="PROP_2" />
<list name="childTableList" fetch="select" lazy="true" table="CHILDTABLE">
<key>
<column name="PK_1" />
<column name="PK_2" />
</key>
<index column="PK_4"/>
<one-to-many class="MyChildClass" />
</list>
</class>
<class name="MyChildClass" table="MYCHILDTABLE">
<composite-id name="id" class="AgentId">
<key-property name="pk1" type="string" column="PK_1" />
<key-property name="pk2" type="string" column="PK_2" />
<key-property name="pk4" type="string" column="PK_4" />
</composite-id>
<property name="prop3" type="string" column="PROP_3" />
<property name="prop4" type="string" column="PROP_4" />
</class>
</hibernate-mapping>
Code between sessionFactory.openSession() and session.close():
Full stack trace of any exception that occurs:
org.hibernate.MappingException: Foreign key (FK33B30AA281A558:child [PK_1,PK_2])) must have same number of columns as the referenced primary key (MYPARENTTABLE [PK_1,PK_2,PK_3])
at org.hibernate.mapping.ForeignKey.alignColumns(ForeignKey.java:90)
at org.hibernate.mapping.ForeignKey.alignColumns(ForeignKey.java:73)
at org.hibernate.cfg.Configuration.secondPassCompileForeignKeys(Configuration.java:1145)
at org.hibernate.cfg.Configuration.secondPassCompile(Configuration.java:1052)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1168)
at xxxxxxxxxxxxxxxx.HibernateUtil.<clinit>(HibernateUtil.java:57)
at xxxxxxxxxxxxxxxx.MyParentClassTest.testFindById(MyParentClassTest.java:38)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at junit.framework.TestCase.runTest(TestCase.java:154)
at junit.framework.TestCase.runBare(TestCase.java:127)
at junit.framework.TestResult$1.protect(TestResult.java:106)
at junit.framework.TestResult.runProtected(TestResult.java:124)
at junit.framework.TestResult.run(TestResult.java:109)
at junit.framework.TestCase.run(TestCase.java:118)
at junit.framework.TestSuite.runTest(TestSuite.java:208)
at junit.framework.TestSuite.run(TestSuite.java:203)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:478)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:344)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:196)


Name and version of the database you are using: DB2/NT, version: 08.01.0003
The generated SQL (show_sql=true): none is generated
Debug level Hibernate log excerpt:

You can't have a foreign key constraint on a primary key in another table unless the types of the keys are identical. It actually doesn't make any sense, since it implies that there could be more than one row in the PK table that matches the FK in a single row in the FK table. That pretty much breaks the relational model. Either the 3 elements identify a row uniquely, or the 2 elements do. Both tables must have the same notion of what the "unique identifier" is. I'm not sure what you are looking for in terms of a "solution".

True, but this kind of relationship frequently occurs in the data. Is there a way to support it in hibernate.

Is a solution to this problem?

both the parent table (primary key ) and the referencing foreign key should have the same number of columns.