Hibernate Select Top and Bottom n Rows with Criteria

Question

Let\'s say I have two tables, Books and Reviews. Reviews has a column, stars, that can have a value between 1 and 5. A Book can have many Reviews.

How would I select al

Answer 1

This would typically be done with something like a union, which you can't do in HQL.

You can do this, though, in HQL

WHERE id in ([SELECT top 3]) or id in ([SELECT bottom 3])

I don't have a way to test this, but this might work too.

DetachedCriteria topN = [ your criteria ] 
DetachedCriteria bottomN = [ your criteria ] 

session.createCriteria(..._
    .add( Property.or(Property.forName("id").in(topN),Property.forName("id").in(bottomN) )
    .list();