Question

这里我有两个实体类。我使用了OneToMany和ManyToOne映射。

@Entity
@Table(name="test_user")
public class TestUser  {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer user_id;
    private String user_name;
    @OneToMany(mappedBy = "testuser", fetch=FetchType.EAGER, cascade = CascadeType.ALL)
    private Set<UserAnswer> answer = new HashSet<UserAnswer>();



    public Set<UserAnswer> getAnswer() {
        return answer;
    }

    public void setAnswer(Set<UserAnswer> answer) {
        this.answer = answer;
    }

    public Integer getUser_id() {
        return user_id;
    }

    public void setUser_id(Integer user_id) {
        this.user_id = user_id;
    }

    public String getUser_name() {
        return user_name;
    }

    public void setUser_name(String user_name) {
        this.user_name = user_name;
    }
    }

这是我的第二个实体类

@Entity
@Table(name="user_answer")
public class UserAnswer {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer answer_id;
    private String answer;

    @ManyToOne
    @JoinColumn(name="user_id")
    private TestUser testuser;


    public TestUser getTestuser() {
        return testuser;
    }
    public void setTestuser(TestUser testuser) {
        this.testuser = testuser;
    }
    public Integer getAnswer_id() {
        return answer_id;
    }
    public void setAnswer_id(Integer answer_id) {
        this.answer_id = answer_id;
    }
    public String getAnswer() {
        return answer;
    }
    public void setAnswer(String answer) {
        this.answer = answer;
    }   
}

当我插入用户并回答时，user_id未存储在user_answer表中。这是我的JSON输入格式。

{
    "user_name":"myname",
    "answer":[
        {
            "answer":"myanswer"
        }
    ]
}

当我获取数据时，我得到像这样的JSON响应，

[
{
    "user_id": 52,
    "user_name": "myname",
    "answer": []
  }
]

这是我的服务代码段

@Autowired
    private TestUserRepository repo;

@Override
    public TestUser addUser(TestUser user) {

        return repo.save(user);
    }

这是我的控制器代码段

@Autowired
    private TestUserApiService service;

    @RequestMapping(value = "/saveuser", produces = { "application/json" }, consumes = { "application/json" }, method = RequestMethod.POST)
    public ResponseEntity<TestUser> addUser(@RequestBody TestUser user)
            throws NotFoundException {
        return new ResponseEntity<TestUser>(service.addUser(user),
                HttpStatus.OK);

    }

Answer 1

你在这里的关系是双向的，这意味着关系的每一方都应该引用另一方。

您的输入格式具有TestUser，其具有UserAnswer设置，因为您在TestUser中级联您的UserAnswer，您希望保持该关系，但您的UserAnswer应该引用TestUser以完成关系。

你可以做两件事，首先你可以使你的关系单向，或者你可以提取即将到来的UserAnswer并将TestUser注入他们然后坚持TestUser

映射的@OneToMany不会对表进行输入

1 个答案: