Hibernate version: 3.0.5

Hello,

What I would like to see, is the ability to define order-by in the collection mappings with properties rather than db columns. The reason is that I often need to sort collection results on data in a table other than said collection table. For example...
<set name="people" order-by="address.city"/>

There's more of an explanation in this post here from someone asking the same question...
http://forum.hibernate.org/viewtopic.ph ... ed+orderby


I'm in the process of porting an app from another ORM to Hibernate. This is one of the few remaining issues I have because I don't see an easy workaround.
So my questions is, is it possible now (i.e. am I missing something?) or will it be in the near future? I checked the release notes for 3.1 and didn't see anything.

Thanks

You can resign from SQL sorting and use sort="natural" clause. This way you enable Java sorting.

change your people from:


to


make sure your Person class implements Comparable. You'll get your collection sorted by TreeSet itself instead of database. It has one big advantage: you can use any sorting predicates you wish.

Thanks for your reply. I am aware of some of the options for sorting in Java. But doesn't that mean you have create a Comparator class for each collection you want to sort?

Either way, it seems many people would want to do the ordering on the DB side. So why the SLQ-centric mapping for order-by? We've gone through the great effort of mapping all our relationships, why not use that instead of a simple column name in the mapping file?


Thanks

This is not currently possible, but we have planned to implement that at some point.
Note that for a @OneToMany, @OrderBy does what you want.

The preferable way is to use an HQL query. (Make more sense for the perf anyway if the ordering is not needed on every collection retrieval).

Ok, it looks like I have some options for now. Thanks for the info.