问题描述
如果将字段注释为insertable=false, updatable=false
,这是否意味着您不能插入值或更改现有值?您为什么要这样做?
If a field is annotated insertable=false, updatable=false
, doesn't it mean that you cannot insert value nor change the existing value? Why would you want to do that?
@Entity
public class Person {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
@OneToMany(mappedBy="person", cascade=CascadeType.ALL)
private List<Address> addresses;
}
@Entity
public class Address {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
@ManyToOne
@JoinColumn(name="ADDRESS_FK")
@Column(insertable=false, updatable=false)
private Person person;
}
推荐答案
当创建/更新相关实体的责任不在当前实体.例如.您有一个Person
和Address
.您想将insertable=false, updatable=false
添加到与Address
实体中的Person
实体的@OneToMany
关系中,仅仅是因为Address
实体不负责创建或更新Person
.恰恰相反.
You would do that when the responsibility of creating/updating the related entity in question isn't in the current entity. E.g. you have a Person
and an Address
. You'd like to add insertable=false, updatable=false
to the @OneToMany
relationship with the Person
entity in the Address
entity, simply because it's not the responsibility of the Address
entity to create or update a Person
. It's the other way round.
这篇关于请参考JPA @Column注释解释有关insertable = false和updatable = false的信息的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!