hbm2ddl tool generates multiple foreign keys while mapping a collection of a class/ interface whose hierarchy is mapped using single_table strategy. ---------------------------------------------------------------------------------------------------------------------------------------------------- Key: HBX-1200 URL: https://hibernate.onjira.com/browse/HBX-1200 Project: Hibernate Tools Issue Type: Bug Components: hbm2doc Environment: Hibernate version: 3.6.0.Final Database: Oracle 10G Reporter: Luca Pedriali Referring to this issue: https://hibernate.onjira.com/browse/HBX-494 , I found a similar problem. Mapping bidirectional ManyToOne relationships to classes of a single_table hierarchy, hbm2ddl generates multiple foreign keys of the same table. For now the only solution is to manually delete the extra foreign keys. Moreover, the solution proposed in the quoted jira (use the foreign-key property) is not applicable for me, because I use hibernate tool with an ant task and my code use only the JPA annotations. Appreciate if we could get a fix or workaround for the same. -- This message is automatically generated by JIRA. For more information on JIRA, see: http://www.atlassian.com/software/jira