Hi, I m trying to use Inheritance , table per hierarchie, I have a first table A
with a composite primary key ( type, id ), id is generated by a sequence
for each value of type ( don't have unique constraint on id but on both type and id ).

I have a second table B which has a foreign key to A.id and no column
for A.type because the value is constant ( all entities of B refers to
A entity for which A.type = 1 )

When I try to map the Many-to-One association, hibernate reject the code
because the foreign key has not the same number of column than the primary key.
I would consider that the discriminator column would be used for the join, but not.

Does someone have an idea on this ?


Hibernate version:3.0.4

Mapping documents:
<class name="A" table="A">
<composite-id name="dicoPk" class="APk">
<key-property name="type" column="type" type="int" />
<key-property name="id" column="id" type="long" />
type="int" />
</composite-id>

<discriminator column="type" type="int" ></discriminator>
<subclass name="SubA" discriminator-value="1" ></subclass>
</class>
<class name="B" table="B" >
<id name="id" column="b_id" type="long" />
<many-to-one name="subA" column="a_id" />
</class>



Full stack trace of any exception that occurs:org.hibernate.MappingException: Foreign key (FK5CA40550C951E49D:B[a_id])) must have same number of columns as the referenced primary key (A[type, id])
at org.hibernate.mapping.ForeignKey.alignColumns(ForeignKey.java:86)
at org.hibernate.mapping.ForeignKey.setReferencedTable(ForeignKey.java:51)
at org.hibernate.cfg.Configuration.secondPassCompileForeignKeys(Configuration.java:953)
at org.hibernate.cfg.Configuration.secondPassCompile(Configuration.java:898)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1049)
at com.nnr.tests.Test.setUp(Test.java:33)
at com.intellij.rt.execution.junit2.JUnitStarter.main(JUnitStarter.java:31)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:78)

Name and version of the database you are using:postgresql 8.0

Let the id to be only "id" not (id, type). It is meaningless to give such a composite id.

I have simplify the example, I can't remove the type from the primary key, I can't modify the structure of the database.

Using a formula tag as child of many-to-one tag helps but I can't be done using Annotations and I feel this ugly.

Thanks for your answer, have any other idea ?