Hi, I'm trying to have a person entity who has a collection of person entities representing his children. I have it marked as follows: | private Collection<Person> children; | ... | @OneToMany | public Collection<Person> getChildren() { | return children; | } | But when I deploy this it gives me the following error. org.hibernate.MappingException: Could not determine type for: java.util.Collection, for columns: [org.hibernate.mapping.Column(children)] I haven't found other examples of entity having instances of themselves but did see a post where someone was having a similar issue relating to having a collection of enitites from a "close relative" on the inheritance tree, so I am not sure whether this is a common issue. Any help is appreciated Jeremy View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3995473#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...