如何使用JPA 2.1 CriteriaDelete从连接表中删除删除实体

Question

我想从一个“医院”中删除（ JPA 2.1 ）所有“患者”，但遇到问题： “UPDATE / DELETE条件查询无法定义连接”

CriteriaBuilder cb = entityManager.getCriteriaBuilder();
CriteriaDelete<PatientEntity> delete = cb.createCriteriaDelete(PatientEntity.class);
Root<PatientEntity> root = delete.from(PatientEntity.class);
Join<PatientEntity, HospitalEntity> join = root.join(PatientEntity_.Hospital);
delete.where(cb.equal(join.get(HospitalEntity_.id), id));
Query query = entityManager.createQuery(delete);
query.executeUpdate();

错误： 的

UPDATE/DELETE criteria queries cannot define joins

如何删除所有患者，而无法执行加入？

Answer 1

您可以使用选择正确实体的子查询和＆＃39;条款。

CriteriaBuilder cb = entityManager.getCriteriaBuilder();
CriteriaDelete<PatientEntity> delete = cb.createCriteriaDelete(PatientEntity.class);
Root<PatientEntity> root = delete.from(PatientEntity.class);


                Subquery<PatientEntity> subquery = delete.subquery(PatientEntity.class);
                Root<PatientEntity> root2 = subquery.from(PatientEntity.class);
                subquery.select(root2);
                /* below are narrowing criteria, based on root2*/   
                Join<PatientEntity, HospitalEntity> join = root2.join(PatientEntity_.Hospital);
                subquery.where(cb.equal(join.get(HospitalEntity_.id), id));


delete.where(root.in(subquery));
Query query = entityManager.createQuery(delete);
query.executeUpdate();