Question

所以我有两个实体：

Person.java

@Entity
@Table(name = "persons")
public class Person {
    @Id 
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;

    @OneToMany(mappedBy="person", cascade = CascadeType.REMOVE)
    @JsonIgnoreProperties("person")
    private Set<Address> addresses;

    //getters and setters

}

Address.java

@Entity
@Table(name = "addresses")
public class Address {
    @Id 
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;

    @NotNull
    @ManyToOne
    @JoinColumn(name = "person_id", nullable = false)
    @JsonIgnoreProperties("addresses")
    private Person person;
    //getters and setters       
}

稍后在我的代码中我有一个personDb对象（已保存在数据库中）然后我添加地址：

Address address = new Address();
address.setPerson(personDb);
address = addressRepository.save(address);

现在我有附加了person对象的地址对象但是我的personDb仍然没有附加任何地址。即使我试图再次从数据库中获取它：

personRepository.findOne（personDb.getId（））;

我有null应该在哪里设置地址。我也尝试将Person类中的注释更改为：

@OneToMany(mappedBy="person", fetch = FetchType.EAGER, cascade = CascadeType.REMOVE)

或将CascadeType更改为ALL但没有任何帮助。将地址添加到数据库后，我该怎么做才能将地址加载到personDb对象中？

Answer 1

这不是最佳解决方案，但尝试在personDB中添加新地址。

Address address = new Address();
address.setPerson(personDb);
personDB.addAddress(address);
personRepo.save(personDB)

Answer 2

确保此人坚持。

为此进行集成测试。如果您使用的是Spring，我还建议您使用内存数据库进行测试。

@Transactional
@Test
public void testFindOneAddress(){

// persist the person
Person person = new Person();
...
personRepository.save(person);

// persist the address
Address address = new Address();
address.setPerson(person);
addressRepository.save(address);

// find the persisted person and addresses
Person queryResult= personRepository.findOne(person.getId());
assertNotNull(queryResult);
assertNotNull(queryResult.getAddresses());
assertEquals(1, queryResult.getAddresses().size());
assertEquals(address.getId(), queryResult.getAddresses().get(0).getId());

}

另外，请确保您的人员ID栏名为“person_id”

public class Person {
    @Id 
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "person_id")
    private Integer id;

从那里拿走

添加子项后刷新一对多关系

2 个答案: