How to limit the results when using CriteriaQuery

Question

I have inherited a groovy code base (that among other things) uses Hibernate as an ORM as part of Dropwizard and I've in the process of updating the dependencies I start seeing the following warnings.

org.hibernate.orm.deprecation: HHH90000022: Hibernate's legacy org.hibernate.Criteria API is deprecated; use the JPA javax.persistence.criteria.CriteriaQuery instead

As an experiment I tried updating one of the queries to use the new CriteriaQuery API. However pretty quickly I ran into an issue, the old code uses setMaxResults() . I assume under the hood this is using the LIMIT to limit the number of results.

How to I limit the results of a CriteriaQuery to 1 ?

A related question, how do I do pagination with CriteriaQuery ?

I tried reading through the Hibernate 5.3 users guide, (especially chapter 16 the the new API ) searing for "limits" and "max results" and such and all the talk I could find was in the " Legacy Hibernate Criteria Queries ".

I'd be happy to provide some example code if it helps, but you could just use the example from the manual ( Example 534. Selecting an attribute ) and show how to enhance it by limiting the results.

Answer 1

这样在Query上定义setFirstResult()和setMaxResults() （offset = 0和limit = 10）：

sessionFactory.getCurrentSession().createQuery(criteriaQuery).setFirstResult(0).setMaxResults(10).getResultList());

Answer 2

To paginate you just have to set the first and max (assuming you're passing in a Pageable Object:

criteria.setFirstResult(pageable.gotOffset());
criteria.setMaxResults(pageable.getPageSize());

Also, to limit, just call:

Criteria queryCriteria = session.createCriteria(MonthlySubscriber.class);
queryCriteria.setFirstResult(0);
queryCriteria.setMaxResults(1);
monthlySubscriberList = queryCriteria .list();