FetchMode in JPA 2 CriteriaQuery

问题

I'm currently in the process of switching from Hibernate to pure JPA 2 (which by the way turned out to be much more time consuming than I initially expected).
The biggest problem I'm having so far is finding a way to force eager loading of lazy properties.
With Hibernate this was done using: criteria.setFetchMode("person", FetchMode.JOIN);.
Is there any way to do this with JPA 2?

回答1:

Try this:

CriteriaQuery<Person> c = cb.createQuery(Person.class);
Root<Person> person = c.from(Person.class);
person.fetch("address");
c.select(person);

Assuming there is a one-to-one relationship between your Person entity and an Address entity.

来源：https://stackoverflow.com/questions/4388486/fetchmode-in-jpa-2-criteriaquery