Question

Do you know a way of implementing something like a Hibernate QBE (Query by Example) in JPA?

For my problem domain the alternative of using it will be to build a SQL query dynamically using some sort of string manipulation, something I would like to avoid.

I know this is not supported by default in the API, but I recognize it as a great technique for building dynamic queries.

Any suggestions?

Answer 1

In JPA 2.0 the closest equivalent is called the Criteria API. It did not exist in JPA 1.0.

Here is a sample:

CriteriaBuilder cb = em.getCriteriaBuilder();
CriteriaQuery c = cb.createQuery(Person.class);
Root person = c.from(Person.class);
c.select(person)
    .where(cb.equal(person.get("name"), "Officer Friendly"));