SELECT * FROM pg_stat_activity WHERE state = 'active';
So you can identify the PID of the hanging query you want to terminate, run this:
SELECT pg_cancel_backend(PID);
Criteria queries allow for multiple root level objects. Caution should be used when doing this, as it can result in Cartesian products of the two table. The where clause should ensure the two objects are joined in some way.
// Select the employees and the mailing addresses that have the same address.
CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder();
CriteriaQuery criteriaQuery = criteriaBuilder.createQuery();
Root employee = criteriaQuery.from(Employee.class);
Root address = criteriaQuery.from(MailingAddress.class);
criteriaQuery.multiselect(employee, address);
criteriaQuery.where(criteriaBuilder.equal(employee.get("address"), address.get("address"));
Query query = entityManager.createQuery(criteriaQuery);
List<Object[]> result = query.getResultList();
A. Imani, A. Vakili, A. Montazer, и A. Shakery. Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), (апреля 2019)
S. Panda, S. Mishra, и S. Mishra. International Journal of Computer Science, Engineering and Information Technology (IJCSEIT), 6 (2):
01-09(апреля 2016)