【发布时间】：2020-07-18 15:08:26
【问题描述】：
我有一个 Spring RESTful API，它使用 H2 数据库和 JPA 来填充一些表。我正在尝试使用字段@OneToMany 设置一个实体，而另一个实体对象是@ManyToOne。当我在 Postman 中发出 POST 请求时，我 sout 我的 Quiz quiz 这是请求正文，字段与预期一致。然而，当我在 localhost 上登录数据库时，只有 quiz_table 更新为正确的属性。
当我发出 POST 请求时，我会在控制台中得到这个输出
Hibernate: insert into quiz_table (answer, text, title, id) values (?, ?, ?, ?)
我的 JSON 请求正文是
{
"title": "Tottenham Quiz",
"text": "When did Tottenham Hotspur last win a trophy?",
"options": ["2002", "2019"],
"answer": 1
}
服务器响应是
{
"id": 67,
"title": "Tottenham Quiz",
"text": "When did Tottenham Hotspur last win a trophy?",
"options": [
{
"id": 0,
"quiz": null,
"option": "2002"
},
{
"id": 0,
"quiz": null,
"option": "2019"
}
]
}
据我所知，"options" 的值正在传递给List<Option>
这是我的控制器与此端点的映射
@PostMapping(path = "api/quizzes", produces = "application/json")
public Quiz addQuiz(@Valid @RequestBody Quiz quiz) {
quizRepository.save(quiz);
return quiz;
}
Quiz 类
@Component
@Entity(name = "quiz_table")
public class Quiz {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private long id;
@NotBlank(message = "Title must not be blank")
private String title;
@NotBlank(message = "Text must not be blank")
private String text;
@Size(min = 2)
// @NotNull
@OneToMany(mappedBy = "quiz")
private List<Option> options;
@JsonIgnore
private int answer;
public Quiz() {}
public Quiz(String title, String text, List<Option> options, int answer) {
this.title = title;
this.text = text;
this.options = options;
this.answer = answer;
}
Option 类
@Component
@Entity(name = "options_table")
public class Option {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private long id;
@ManyToOne
@JoinColumn
private Quiz quiz;
private String option;
// for Jackson deserielization
public Option() {
}
/*public Option(Quiz quiz, String option) {
this.quiz = quiz;
this.option = option;
}*/
public Option(String option) {
this.option = option;
}
// getters/setters
编辑：实施建议后的异常 JSON 响应
{
"id": 1,
"title": "Tottenham Quiz",
"text": "When did Tottenham Hotspur last win a trophy?",
"options": [
{
"id": 2,
"quiz": {
"id": 1,
"title": "Tottenham Quiz",
"text": "When did Tottenham Hotspur last win a trophy?",
"options": [
{
"id": 2,
"quiz": {
"id": 1,
"title": "Tottenham Quiz",
"text": "When did Tottenham Hotspur last win a trophy?",
"options": [
{
"id": 2,
"quiz": {
"id": 1,
"title": "Tottenham Quiz",
"text": "When did Tottenham Hotspur last win a trophy?",
"options": [
{
"id": 2,
"quiz": {
"id": 1,
"title": "Tottenham Quiz",
"text": "When did Tottenham Hotspur last win a trophy?",
"options": [
{
"id": 2,
"quiz": {
"id": 1,
"title": "Tottenham Quiz",
"text": "When did Tottenham Hotspur last win a trophy?",
"options": [
{
"id": 2,
"quiz": {
"id": 1,
"title": "Tottenham Quiz",
"text": "When did Tottenham Hotspur last win a trophy?",
"options": [
{
"id": 2,
"quiz": {
"id": 1,
"title": "Tottenham Quiz",
"text": "When did Tottenham Hotspur last win a trophy?",
"options": [
{
"id": 2,
"quiz": {
"id": 1,
"title": "Tottenham Quiz",
"text": "When did Tottenham Hotspur last win a trophy?",
"options": [
{
"id": 2,
"quiz": {
"id": 1,
"title": "Tottenham Quiz",
"text": "When did Tottenham Hotspur last win a trophy?",
"options": [
{
"id": 2,
"quiz": {
"id": 1,
"title": "Tottenham Quiz",
"text": "When did Tottenham Hotspur last win a trophy?",
"options": [
{
"id": 2,
"quiz": {
"id": 1,
"title": "Tottenham Quiz",
"text": "When did Tottenham Hotspur last win a trophy?",
"options": [
{
"id": 2,
"quiz": {
"id": 1,
"title": "Tottenham Quiz",
"text": "When did Tottenham Hotspur last win a trophy?",
"options": [
{
"id": 2,
"quiz": {
"id": 1,
"title": "Tottenham Quiz",
"text": "When did Tottenham Hotspur last win
// ... continues for 4000 lines!
【问题讨论】：
-
您是否尝试添加级联选项？我认为这就是您无法保存子实体的原因。
-
我完全忽略了这一点。我猜没有默认设置？