从@ OneToMany-association中删除子项：CascadeType.ALL + orphanRemoval = true not working

我很难从OneToMany协会中删除孩子。 我的实体：

@Entity @Table(name = "PERSON") public class PersonEntity extends BaseVersionEntity implements Comparable { ... // bi-directional many-to-one association to Project @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "person", orphanRemoval = true) private final Set projects = new HashSet(); ... @Entity @Table(name = "PROJECT") public class ProjectEntity extends BaseVersionEntity { @EmbeddedId private ProjectPK id; ... // bi-directional many-to-one association to UdbPerson @ManyToOne(fetch = FetchType.LAZY) @JoinColumn(name = "PERSON_ID", nullable = false, insertable = false, updatable = false) private PersonEntity person; ... @Embeddable public class ProjectPK implements Serializable { // default serial version id, required for serializable classes. private static final long serialVersionUID = 1L; @NotNull @Column(name = "PERSON_ID") private Long personId; ... 

我未能成功删除孩子：

 personEntity.getProjects().clear(); 

这有效，但我不认为这是正确的方法：

 for (Iterator iterator = personEntity.getProjects().iterator(); iterator.hasNext();) { ProjectEntity projectEntity = iterator.next(); projectDao.deleteEntity(projectEntity); iterator.remove(); } 

我在这做错了什么？

谢谢
强尼

Answer 1

关联是双向的，双向关联的拥有方是没有mappedBy属性的关联。 这意味着在这种情况下，拥有方是项目方。

Hibernate只考虑拥有方来知道关联是否存在。 这意味着要破坏人员和项目之间的关联，您必须在项目中将人员设置为null 。