mysql Java JPA/Hibernate级联删除

Question

我正在使用Java8、JPA、Hibernate 5.2.1.Final、Spring 4.3.1.RELEASE和MySQL

表：

如您所见，我有一个job表连接到了一个location_job表，它利用了连接表job_location

+---------+         +--------------+        +---------------+
|   job   |         | job_location |        |  location_job |
+---------+         +--------------+        +---------------+
|   ID    |         |   JOB_ID     |        |     ID        |
|         |         |   LOC_ID     |        |     LAT       |
|         |         |              |        |     LONG      |
+---------+         +--------------+        +---------------+

我正在对job表执行delete，还想删除job_location和location_job表上的相应条目

代码：

目前，我的代码成功地从job和job_location表中删除，但没有从location_job表中删除相应的条目

工作。java

@OneToMany(cascade = CascadeType.ALL, fetch = FetchType.EAGER)
@JoinTable(name = "job_location", joinColumns = {
        @JoinColumn(name = "JOB_ID", referencedColumnName = "ID") }, inverseJoinColumns = {
                @JoinColumn(name = "LOC_ID", referencedColumnName = "ID", unique = true) })
private Set<LocationJob> locations;

JobDaoImpl。java

@Repository("jobDao")
public class JobDaoImpl extends JpaDao<Long, Job> implements JobDao {

    @Override
    public boolean delete(Job job) {
        Set<LocationJob> locations = job.getLocations();
        if (locations != null) {
            for (LocationJob location : locations) {
                entityManager.remove(location);
            }
            job.getLocations().clear();
        }       
        entityManager.remove(job);
        return true;
    }
}

JpaDao。java

public class JpaDao<I, T extends AbstractDomain<I>> {

    protected Class<T> entityClass;

    @PersistenceContext
    protected EntityManager entityManager;

    @SuppressWarnings("unchecked")
    protected JpaDao() {
        ParameterizedType genericSuperclass = (ParameterizedType) getClass().getGenericSuperclass();
        this.entityClass = (Class<T>) genericSuperclass.getActualTypeArguments()[1];
    }

    protected void remove(T entity) {
        entityManager.remove(entity);
    }
}

问题

当我从job表中删除时，如何使它也从location_job表中删除

多谢各位

Answer 1

我找到了答案

我需要添加orphanRemoval=true：

@OneToMany(cascade = CascadeType.ALL, fetch = FetchType.EAGER, orphanRemoval=true)
@JoinTable(name = "job_location", joinColumns = {
        @JoinColumn(name = "JOB_ID", referencedColumnName = "ID") }, inverseJoinColumns = {
                @JoinColumn(name = "LOC_ID", referencedColumnName = "ID", unique = true) })
private Set<LocationJob> locations;