JPA条件加入3个表并仅返回其组中最大日期时间的不同值

Question

有没有办法用JPA2 CriteriaBuilder写下以下查询的等价物？

select distinct (a.project_id,c.json) from object_metadata a, project b, (select * from task t where t.queued = (select max(queued) from task t2 where t2.project_id=t.project_id)) c where a.implementation = 'localfs' 
and c.project_id = a.project_id;

我写了以下查询，但结果不一样：

CriteriaBuilder cb = getEm().getCriteriaBuilder();
        CriteriaQuery<Tuple> cq= cb.createTupleQuery();
        Root<ObjectMetadata> root = cq.from(ObjectMetadata.class);
        Path<Task> task = root.get("task");
        Expression<org.joda.time.LocalDateTime> queued_ = task.get(Task_.queued);
        Expression<String> sJSON = task.get(Task_.sJson);
        Path<Project> project = root.get("project");
        Expression<String> projectId = project.get("id");
        Expression<String> projectName = project.get("name");
        Subquery<org.joda.time.LocalDateTime> subquery = cq.subquery(org.joda.time.LocalDateTime.class);
        Root<Task> subRoot = subquery.from(Task.class);
        Path<Project> subProject = subRoot.get("project");
        Expression<String> subProjectId = subProject.get("id");
        Expression<org.joda.time.LocalDateTime> queued = subRoot.get(Task_.queued);
        subquery.select(cb.greatest(queued));
        subquery.where(cb.equal(subProjectId, projectId));
        cq.multiselect(projectId.alias("ID"), projectName.alias("NAME"), sJSON.alias("JSON")).distinct(true);
        cq.where(cb.and(cb.equal(root.get(ObjectMetadata_.implementation), "localfs"),cb.equal(queued_, subquery)));
        TypedQuery<Tuple> tq = getEm().createQuery(cq);