java - 更新子项时如何更新jpa中双向关系所有者的fk

Question

第一个定义

简单地说，我有 2 个实体，第一个是用户，第二个是地址，每个用户都可以有一个或多个地址。这意味着，我想要用户和地址之间的双向 OneToMany 关系。

问题

当我更新我的用户并删除一些地址(具有 2 个地址列表的用户)并在保存用户之后，我有一个具有 3 个地址的用户(具有 3 个地址列表的用户)，然后保存用户，地址的 fk 是没有更新。

I expect my new user has 2 addresses after the update but the addresses weren't changed.

In Brief: Address table's fk is not updated when I update a list of it from User.

用户实体(只写地址字段)

@Entity
@Table(name = TABLE_NAME)

public class User {

public static final String TABLE_NAME = "User";

//Some Fields Like ID  , name ,...

@OneToMany(cascade = CascadeType.ALL, mappedBy = "user")
@JsonManagedReference
private List<Address> addresses;

public List<Address> getAddresses() {
    return addresses;
}

public void setAddresses(List<Address> addresses) {
    this.addresses = addresses;
}
}

地址实体(只写用户字段)

@Entity
@Table(name = TABLE_NAME)

public class Address {
public static final String TABLE_NAME = "ADDRESS";

//Some Fields Like ID  , name ,...

@ManyToOne(cascade = CascadeType.ALL)
@JoinColumn(name = "user_id")
@JsonBackReference
private User user;

public User getUser() {
    return user;
}

public void setUser(User user) {
    this.user = user;
}
}

服务等级

@Service
public class UserService

@Autowired
UserRepository repository;

public updateUserAddress() {

    //Get User With Id of 1
    User user = repository.findById(1L);

    //Get Addresses
    List<Address> addresses = user.getAddresses();

    //Delete One Address From List
    addresses.remove(0);

    //Set New Address to User Entity
    user.setAddresses(addresses);

    //Save User 
    repository.save(user)

    //It doesn't work (List of Address of user is the same and not changed)

}

顺便说一句，我在 DAO 层使用 Spring-data-jpa 和 Hibernate。

Answer 1

通过在 User 实体中添加 removeAddress 方法，您可以更新 address 表的 fk，并且您还可以保留该行:

public void removeAddress(Address address) {
    address.setUser(null); // or the value you want
}

updateUserAddress 方法应该是这样的:

public void updateUserAddress() {

    User user = repository.findById(1L);
    List<Address> addresses = user.getAddresses();

    Address address = addresses.get(0); //the address to be removed
    user.removeAddress(address); 

    user.setAddresses(addresses);

    repository.save(user);

}

用户实体:

@Entity
@Table(name = "users")
public class User {
    // other fields

    @OneToMany(cascade = CascadeType.ALL, mappedBy = "user", fetch=FetchType.EAGER)
    @JsonManagedReference
    private List<Address> addresses;

    // getters, setters, constructors etc.

    // the remove method
    public void removeAddress(Address address) {
        address.setUser(null);
    }
}

地址实体:

@Entity
@Table(name = "address")
public class Address {
    // other fields

    @ManyToOne
    @JoinColumn(name = "user_id")
    @JsonBackReference
    private User user;

    // getters, setters, constructors etc.
}