Example usage for javax.persistence.criteria Join isNotNull

Introduction

In this page you can find the example usage for javax.persistence.criteria Join isNotNull.

Prototype

Predicate isNotNull();

Source Link

Document

Create a predicate to test whether the expression is not null.

Usage

From source file:dao.jpa.TestJpaDao.java

@Test
@Transactional//from  ww  w .j  a  va  2 s.  c  o  m
public void testCountCriteria() {
    EntityManager em = bookDao.getEntityManager();
    CriteriaBuilder cb = em.getCriteriaBuilder();
    CriteriaQuery<Book> criteria = cb.createQuery(Book.class);

    Root<Book> root = criteria.from(Book.class);
    Join<Book, Author> join = root.join("author");
    criteria.where(join.isNotNull());

    CriteriaQuery<Long> countCriteria = JpaUtils.countCriteria(em, criteria);
    Long result = em.createQuery(countCriteria).getSingleResult();
    log.debug("Count: " + result);
}

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