ejb-ql: using non-standard class types as parameter

[gzhong]

if I have something like:

findAllUserFolders(User user),

how do I formulate a sql statement in ejb-jar.xml that queries all the top level folders that belong to this user? With normal sql I would:
select * from folder_tbl where user_id=3 and parent_id=-1
I can't use foreign keys here because there's this extra constraint of the parent_id being -1 (parent id points to the folder that this folder belongs to, and -1 or null is an indication that this folder belongs to no folder). Note that "user" is also another registered EJB entity bean.

Thanks,
G

[dsundstrom]

I can't really say without seeing the abstract schema, but I would guees something like this would work.

SELECT OBJECT(f)
FROM Folder f
WHERE f.user=?1 AND f.parent IS NULL

or something like this

SELECT OBJECT(f)
FROM Folder f
WHERE f.user=?1 AND f.parent.id = -1