bidirectional reflexive OneToMany association

blabla · **Joined:** Fri Mar 14, 2008 9:53 am **Posts:** 2

Hello,

I've got a strange problem with hibernate and a bidirectional reflexive association in order to realize a tree. Here's the class with the appropriate annotations.

Code:

public class Node extends HibernateObject
{
        private String name="";

   @OneToMany
   @IndexColumn(name="subNodesIndex", base=0)
   @JoinTable(name="Node_Node",
            joinColumns={@JoinColumn(name="parentNode_ID")},
            inverseJoinColumns={@JoinColumn(name="subNode_ID")})
   private List<Node> subNodes = new Vector<Node>();

   @ManyToOne
   @JoinTable(name="Node_Node", 
            joinColumns={@JoinColumn(name="subNode_ID")},
            inverseJoinColumns={@JoinColumn(name="parentNode_ID")})
   private Node parentNode = null;
}

I'm using a join table so that Hibernate knows that it's one association. When loading the list of all nodes, the hql statement "FROM Node" gets executed. But Hibernate transforms the query in this way

Code:

SELECT name, parentNode_ID FROM Node

which is apparently incorrect because parentNode_ID is not an attribute of the nodes table. Thus, I get an error message like this one

Code:

Unknown column 'node0_.parentNode_ID' in 'field list'

and the execution of the query fails. What am I doing wrong? The hibernate version in use is 3.2.5.ga. Any help would be greatly appreciated. Thanks in advance,

blabla

Cameron McKenzie · **Posted:** Tue Sep 09, 2008 8:12 pm

Well, it's just that - the node does not exist.

Could you perhaps run a SchemaExport on the class and have Hibernate create the tables? Then the table and column it needs would be created and would exist. Possible?