Incorrect SQL generated when one-to-many foreign key is in a discriminated subclass table ----------------------------------------------------------------------------------------- Key: HHH-1015 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-1015 Project: Hibernate Core Issue Type: Bug Components: core Affects Versions: 3.1 beta 2, 3.5.1 Environment: Hibernate versions 3.1 beta 3 and 3.0.5 Reporter: Steven Grimm Priority: Minor Attachments: 3.3.2.GA-HHH-1015-v1.patch, hhh-1015-version2.patch, hhh-1015.patch I have the following mappings describing a hierarchy of events and a class that the events refer to: <hibernate-mapping package="com.xyz"> <class name="Event" table="event" discriminator-value="-1"> <id name="Id" type="long" column="event_id"/> <discriminator column="event_type_id" type="integer" /> <subclass name="EventPayer" discriminator-value="-3"> <join table="event_payer"> <key column="event_id" /> <many-to-one name="payer" column="payer_id" class="Payer" /> </join> <subclass name="EventPayerCreated" discriminator-value="1" /> </subclass> </class> <class name="Payer" table="payer"> <id name="payerId" column="payer_id" type="java.lang.Long"/> <set name="eventPayers" inverse="true" cascade="save-update"> <key column="payer_id"/> <one-to-many class="EventPayer"/> </set> </class> </hibernate-mapping> When I fetch the Payer.eventPayers collection, Hibernate generates this SQL: select eventpayer0_.payer_id as payer7_1_, eventpayer0_.event_id as event1_1_, eventpayer0_.event_id as event1_5_0_, eventpayer0_1_.payer_id as payer2_6_0_, eventpayer0_.event_type_id as event2_5_0_ from event eventpayer0_ inner join event_payer eventpayer0_1_ on eventpayer0_.event_id=eventpayer0_1_.event_id where eventpayer0_.payer_id=? The problem is that there is no event.payer_id column; payer_id is in the child table, not the parent. It appears that specifying a discriminated subclass in <one-to-many> is the same as specifying the superclass, or that Hibernate is ignoring the subclass's <join> element. As far as I can tell, this leaves no way to resolve bidirectional associations where one end of the association is in a discriminated subclass, which seems like a perfectly reasonable thing to want to do. I also tried changing <key column="payer_id"/> to <key property-ref="payer"/> in the Payer class's <set> element, but got similar behavior in the form of a "property not found" error: Hibernate is either looking in the superclass's properties rather than the subclass's or is ignoring the list of properties in the <join> element.