hi!
i'm looking for a solution to the following problem:

i have a post and a media table. a post has a set of media elements:



the table structure looks like this:
table post (title, text)
table media (title, url)
table post_media (post_pk, media-pk)

now i want to be able to control the order of the media elements for a post, in fact if i submit the post initially but i also want to be able to change the order of the posts' media elements later on after the post has been submitted.

so my problem is that a media element can be referenced in more than one post, so i can't just add an int order property to my media element which i can use to sort the media elements in my client code.

You can use List instead of Set. Lists have an order, and hibernate can solve the problem for you. I have an example with a class called MenuEntity which has a List of Elements




The important thing here is the @IndexColumn annotation. You can find more documentation in hibernate annotations online doc:
2.4.6.2. Extra collection types
2.4.6.2.1. List

Hope this helps!

That worked, thanks!