All JPQL queries are polymorphic, which means the from clause of a query includes not only instances of the specific entity class to which it refers, but all subclasses of that class as well. The instances returned by a query include instances of the subclasses that satisfy the query conditions. For example, the following query may return instances of Magazine, as well as Tabloid and Digest instances, where Tabloid and Digest are Magazine subclasses.

select x from Magazine x where x.price < 5