请解释一下：insertable = false，updatable = false [英] Please explain about: insertable=false, updatable=false

问题描述

如果某个字段已注释 insertable = false，updatable = false ，这是否意味着您不能插入值也不能更改现有值？你为什么要这样做？

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

你会这样做的创建/更新相关实体的责任不在当前实体中。例如。你有人和地址。您想将 insertable = false，updatable = false 添加到 @OneToMany 与<$ c $的关系c>人 地址实体中的实体，仅仅因为它不是地址实体创建或更新人。反之亦然。

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.

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