Re: [Hibernate] Polymorphic queries, where and order by

[Emmanuel Bernard]

Speaking from memory, Gavin did implement something on the (now dead 2.2 branch). It now has been reporded on H3. Did you test it? I can remembe, he'd implemented the transparent subclassing (no special keyword). March, Andres wrote: I'm sorry if I expand the subject a little. We pulled a patch off the forums some where that allows us to order by any association. I was wondering why this patch never got applied. It seems it would be useful in this situation as well. I am really uncomfortable using a patched hibernate because there are less eyes on it and it makes upgrading harder. I can submit the patch as we've applied it if you like. But also let me know if there is any reason for not allowing this type of functionality. It has been extremely useful to us in our searches as I think it would be to others. -----Original Message----- From: [EMAIL PROTECTED] [mailto:hibernate-devel- [EMAIL PROTECTED]] On Behalf Of William Draï Sent: Tuesday, September 28, 2004 1:31 AM To: [EMAIL PROTECTED] Subject: [Hibernate] Polymorphic queries, where and order by Let's say we have the following (simplified) mapping : <class name="A" table="T"> <property name="field1" type="string"/> <subclass name="B"> <property name="field2" type="string"/> </subclass> </class> Now we can execute any HQL query on the class A using the field1, for example "from A a where a.field1 like 'anything%'" or "from A a order by a.field1" The problems come when we want to use the field2 with the same queries. Of couse in simple SQL it is possible to do select * from T order by field2 But in HQL, "from A a order by a.field2" rightly fails because field2 is not defined for class A. This causes problems in sortable or filtered data tables where the user can sort or filter by any column he wants. There is currently only two options : - allowing to sort only on columns of class A : possible but my users won't be really happy - "casting" the query to class B when the user sorts on a column of class B : that means that the results count of the query is not the same when it is sorted than when it is not ; it completely breaks the semantics of sorting/filtering I understand it does not follow the OO approach of HQL but it would be really useful to have an additional syntax to allow using fields of the subclass in HQL queries, something like "select a from A+ a order by a.field2", or maybe an option in the Query interface like query.setUseInheritedProperties(true). What do you think of this ? Note : this is an extension of the JIRA HB-792 and could allow to resolve this case in a better way William ------------------------------------------------------- This SF.Net email is sponsored by: YOU BE THE JUDGE. Be one of 170 Project Admins to receive an Apple iPod Mini FREE for your judgement on who ports your project to Linux PPC the best. Sponsored by IBM. Deadline: Sept. 24. Go here: http://sf.net/ppc_contest.php _______________________________________________ hibernate-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/hibernate-devel ------------------------------------------------------- This SF.net email is sponsored by: IT Product Guide on ITManagersJournal Use IT products in your business? Tell us what you think of them. Give us Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out more http://productguide.itmanagersjournal.com/guidepromo.tmpl _______________________________________________ hibernate-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/hibernate-devel -- Emmanuel Bernard 01.55.21.52.14 Fnac - DSI Direction France - Nouvelles technologies 67, boulevard du Gal Leclerc 92612 Clichy Cedex