How do I write a MAX query with a where clause in JPA 2.0?

Question

I\'m using JPA 2.0. Hibernate 4.1.0.Final, and Java 6. How do I write a JPA query from the following psuedo-SQL?

select max(e.dateProcessed) from Event e wh         


        

Answer 1

With JPQL and CriteriaBuilder

CriteriaBuilder cb = getEntityManager().getCriteriaBuilder();
javax.persistence.criteria.CriteriaQuery cq= getEntityManager().getCriteriaBuilder().createQuery();
Root c = cq.from(getEntityClass());
cq.select(cb.max(c.get("id")));