Question

SpringBoot版本：1.4.2.RELEASE MySQL版本：5.7.16 Lombok的

我有两个实体类问题和选项，其中Question表中的question_id是Question_Option表中的外键。

问题实体

@Entity
@Table(name = "questions")
public class Question {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Getter
@Setter
private int questionId;
@Getter
@Setter
@OneToMany(mappedBy = "question",fetch=FetchType.LAZY,   cascade=CascadeType.ALL)
private List<Option> option;

选项实体

@Entity
@Table(name = "questions_options")
public class Option {
@Id
@GeneratedValue
@Getter
@Setter
private int id;
@Getter
@Setter
private String optionsId;
@Getter
@Setter
 private String optionText;
@ManyToOne
@JoinColumn(name="questionId")
@Getter
@Setter
private Question question;
}

问题陈述当我尝试POST时，外键（question_id）未插入选项表中。

Hibernate: insert into questions (questionId, LastUpdate, active, createTime, questionText, questionType) values (default, ?, ?, ?, ?, ?)
Hibernate: insert into questions_options (id, lastUpdate, optionText, optionsId, questionId) values (default, ?, ?, ?, ?)
Hibernate: insert into questions_options (id, lastUpdate, optionText, optionsId, questionId) values (default, ?, ?, ?, ?)

Hibernate：插入questions_options（id，lastUpdate，optionText，optionsId，questionId）值（默认值，？，？，？，？）

我是如何解决这个问题的？我将Question实体改为

@Getter
@Setter
@OneToMany(fetch=FetchType.LAZY, cascade={CascadeType.PERSIST, CascadeType.MERGE, CascadeType.REMOVE})
@JoinColumn(name="questionId")
@NotNull
private List<Option> option;

和选项

@ManyToOne
@Getter
@Setter
@JoinColumn(name="questionId")
private Question question;

但我想知道为什么第一种方法不起作用，我做错了什么。

Answer 1

尝试以下关系，它应该有效。

问题实体

@OneToMany(mappedBy = "question",fetch=FetchType.LAZY,cascade=CascadeType.ALL, targetEntity = Option.class)
private List<Option> option

选项实体

@ManyToOne
@JoinColumn(name = "questionId")
private Question question;

Answer 2

这就是控制器类中的样子。

@PostMapping("/question")
public question addQuestion(@RequestBody Question question) {

    if( question.getOption().size() > 0 )
    {
        question.getOption().stream().forEach( option -> {
            option.setQuestion( question );
        } );
    }

   // You can save this question object now using the repository instance autowired.
    return question;
}

还有一件事情，在Option类实体中，您需要如下添加@JsonIgnore注释，以避免递归获取

@ManyToOne
@Getter
@Setter
@JoinColumn(name="questionId")
@JsonIgnore
private Question question;

SpringBoot_JPA：OneToMany（双向）不在子表中插入外键

2 个答案: