How to select max id after join using JPA criteria?

See more:

JPA

Hibernate

I'm selecting max id of Dosage entity after join Farmers entity:

cq.select(cb.max(root.get("id")))
.where(cb.equal(root.join("farmers").get("id"), id));

It doesn't return uniqueResult(); but all Farmers instead.

What I have tried:

public Dosage maxDose(int id) {
        try (Session session = sf.openSession()) {
            CriteriaBuilder cb = sf.getCriteriaBuilder();
            CriteriaQuery cq = cb.createQuery();
            Root<Dosage> root = cq.from(Dosage.class);

             cq.select(cb.max(root.get("id"))).where(cb.equal(root.join("farmers").get("id"), id));
            cq.select(root);
            return (Dosage) session.createQuery(cq).uniqueResult();
        }
    }  

I've solved by :

public int maxDate(int id) {
    try (Session session = sf.openSession()) {
        return (int) session.createQuery("SELECT max(d.id) FROM Dosage d, Farmers f WHERE f.id = " + id).uniqueResult();
    }
}

But how to accomplish using JPA criteria?