When I try to delete a subclass entity, the resulting SQL is bad; it appears to be assuming an alias is being used when it isn't. Mapping file (partial): <hibernate-mapping> <class name="com.wotif.jaguar.domain.Comment" table="COMMENTS" dynamic-update="false" dynamic-insert="false" select-before-update="false" optimistic-lock="version" discriminator-value="null" > ... <subclass name="com.wotif.jaguar.domain.property.PropertyComment" dynamic-update="false" dynamic-insert="false" discriminator-value="0" > ... </class> </hibernate-mapping> 19/04/2005 14:25:20 org.hibernate.hql.ast.QueryTranslatorImpl generate FINE: HQL: delete from com.wotif.jaguar.domain.property.PropertyComment 19/04/2005 14:25:20 org.hibernate.hql.ast.QueryTranslatorImpl generate FINE: SQL: delete from COMMENTS where propertyco0_.CommentType=0 Under Hibernate 2.1.6, the generated SQL was: delete from COMMENTS propertyco0_ where propertyco0_.CommentType = 0 My guess: the change to remove aliasing for update/deletes caused this to break.