I have the following class:

public class Project {
private List<Organisation> organisations;
private List<Person> contacts;

I have lazy loading turned on for performance reasons. If I get a single project by it's ID though, i'd like to eagerly load the collections of organisations and contacts. Something like...

<query name="Project.getById">
from Project as p
left join fetch p.organisations
left join fetch p.contacts
where p.id = :projectId
</query>

Using the above HQL and then calling project.getOrganisations(), I'm getting duplicate records, due to the fact that my HQL returns a cartesian product (I think).

I am assuming that I could get around this using something like fetch="subselect" in my collection mapping - but I don't want any eager loading turned on by default.

So - is there a way that I gan eagerly load everything related to Project, but only when a 'getById' happens (i.e. only when a single entity is loaded) ?

You could use a query to load the object allowing you to 'join fetch' the collections:

The uniqueResult() call eliminates the duplicate records from the result set. "id" will be substituted by hibernate in SQL for the primary key of your project table.

Alternatively, load the object with load() then initialise the collections with Hibernate.initialize(project). This will issue subselects for the collections but might be more efficient than creating the cartesian product of project*organisations*contacts.

Mike

Thanks for the help, load() ing is the way to go for me I think.