使用orderBy（）时，Hibernate Criteria API会生成带有聚合的无效SQL

Question

I am using JPA in a project that uses Spring Data with Hibernate's Criteria API underneath. Using JpaSpecificationExecutor I was able to create queries that would let me use filtering and paging at the same time in my repository using a Specification , by just calling Page<EventPost> findAll(Specification<EventPost> specification, Pageable pageable); without a hitch.

The Problem that I have now, is that I can't order the results without hibernate generating invalid queries like this one:

select count(eventpost0_.event_id) as col_0_0_ from event_post eventpost0_ where eventpost0_.category_event_category_id=? order by eventpost0_.createDate desc

Apparently, Hibernate has to count the rows before it issues the real finder query, and erroneously adds the order by clause from my Criteria to the select count(*) statement.

This is verbatim what I see in the logs:

2016-09-05 09:22:36.987 [http-bio-8080-exec-4] DEBUG org.hibernate.SQL - select count(eventpost0_.event_id) as col_0_0_ from event_post eventpost0_ where eventpost0_.category_event_category_id=? order by eventpost0_.createDate desc
2016-09-05 09:22:36.991 [http-bio-8080-exec-4] WARN  o.h.e.j.spi.SqlExceptionHelper - SQL Error: 0, SQLState: 42803
2016-09-05 09:22:36.992 [http-bio-8080-exec-4] ERROR o.h.e.j.spi.SqlExceptionHelper - ERROR: column "eventpost0_.createdate" must appear in the GROUP BY clause or be used in an aggregate function
  Position: 133

And this is how I create my query

@Override
public Predicate toPredicate(Root<EventPost> root, CriteriaQuery<?> query, CriteriaBuilder cb) {
        Path<EventPost> category = root.get("category");
        Path<Long> participants = root.get("participants");
        Path<EventPostType> eventPostType = root.get("eventPostType");

        final List<Predicate> predicates = new ArrayList<Predicate>();

        if(criteria.getEventCategory()!=null){
            predicates.add(cb.equal(category,criteria.getEventCategory()));
        }

        if(criteria.getParticipantsFrom()!=null){
            predicates.add(cb.ge(participants,criteria.getParticipantsFrom()));
        }else if(criteria.getParticipantsTo()!=null){
            predicates.add(cb.lt(participants,criteria.getParticipantsTo()));
        }

        if(criteria.getEventPostType()!=null){
            predicates.add(cb.equal(eventPostType,criteria.getEventPostType()));
        }

        query.orderBy(cb.desc(root.get("createDate")));

        return cb.and(predicates.toArray(new Predicate[predicates.size()]));
}

When I remove query.orderBy(cb.desc(root.get("createDate"))); , everything works fine. Any Ideas what might be wrong here?

Versions are as follows:

PostgreSQL Database 9.5.3.0 with PostGIS
spring-orm:jar:4.2.5.RELEASE
spring-data-jpa:jar:1.9.4.RELEASE
hibernate-spatial:jar:4.3:compile
hibernate-core:jar:4.3.11.Final:compile
postgresql:jar:8.4-701.jdbc4:compile
postgis-jdbc:jar:1.5.2:compile

Answer 1

I have the following code which worked for me 

CriteriaBuilder cb = em.getCriteriaBuilder();
    CriteriaQuery<T> cq = cb.createQuery(entity);
    Root<T> root = cq.from(entity);

 cq.orderBy(cb.desc(cb.sum(root.get(orderByString))));

// orderByString is string entity field that is being aggregated and which we want to put in orderby clause as well.