JPA multiple joins

join, jpa, jpql

Solution

This should do what you expect:

SELECT resource FROM Project p INNER JOIN p.resources as resource

EDIT:

I forgot a part of the initial question:

SELECT resource FROM Project p INNER JOIN p.resources as resource where p.owner.country = :country

Problem

I have these classes ``` class Project { @ManyToOne Company owner; @ManyToMany Set<Person> resources; } class Company { @ManyToOne Country country; } class Person { } ``` How can I write a JPQL to get the all the resources working on projects for companies in a specific country? The one below doesn't seem to work (using DataNucleus) ``` SELECT r FROM Project p JOIN p.resources r JOIN p.owner c WHERE c.country = :country ``` It tries to join `r` with `c` and of course does not have the `owner` property and a NullPointerException is raised inside DataNucleus.

Original source