AnnotationException: MappedBy 引用未知的目标实体属性 - 映射继承的类

Question

我有这样的继承实体

    @MappedSuperclass
    public class PostEntity {
    ...
        @ManyToOne
        @JoinColumn(name = "user_id")
        private UserEntity author;
    }

    @Entity
    @Table(name = "answers")
    public class AnswerEntity extends PostEntity {}

    @Entity
    @Table(name = "users")
    public class UserEntity {
    ...
        @OneToMany(mappedBy = "author", cascade = CascadeType.ALL, fetch = FetchType.LAZY, orphanRemoval = true)
        private List<AnswerEntity> answers;
    }

在编译过程中，他把我扔了

Caused by: org.hibernate.AnnotationException: mappedBy reference an unknown target entity property: com.example.demo.jpa.entity.AnswerEntity.author in com.example.demo.jpa.entity.UserEntity.answers

不知道为什么他在映射过程中看不到author字段。

Answer 1

JPA 不支持，至少 Hibernate 不支持。您可以：

@OneToMany(mappedBy = "author")
private List<PostEntity> answers;

或将 UserEntity author 字段移至 AnswerEntity。