Here's the situation. I have Documents and Authors, with a many-to-many
relationship. However, the ordering of the authors of a document must be
preserved, so this is implemented via an intermediate DocumentAuthor
class, with many-to-one relationships to the other two classes.

The DocumentAuthor class also has an integer attribute that records the
position of the associated author in the list of authors of the associated
document. I then define the Document -> DocumentAuthor association as
an ordered map.

Now I want to query for documents, ordered by the names of the first
authors. In other words, the usual way one would sort a bibliography.

I tried this:

select d from Document as d
order by d.documentAuthors[0].author.lastName

But it gets a syntax error (net.sf.hibernate.QueryException: Incorrect query syntax).

A similar query

select d from Document as d
where d.documentAuthors[0].author.lastName = 'Smith'

works as expected.

So, is there a way to do what I want, or even an obscure workaround?
Or will I have to do the sorting in my code, rather than use the database?

You can use "[]" outside of the where clause.

In Hibernate 2.1, try using the index() function.

Oh. oops. index() doesn't work for a many-to-many yet, I think.

nah, probably not possible right now. You might need to re-model as a composite-element mapping (in v2.1, still)

It looks like this works