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

Question

我有这样的实体继承

    @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;
    }

在编译期间，他把我扔掉了

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

我不知道为什么他在映射过程中没有看到author字段。

Answer 1

JPA不支持它，至少不支持Hibernate。你可以有：

   <speak>
        1. The numbers are: <say-as interpret-as="digits">5498</say-as>.
        2. The numbers are: <say-as interpret-as="spell-out">5498</say-as>.
        3. The numbers are: <say-as interpret-as="characters">5498</say-as>.
        4. The numbers are: <prosody rate="x-slow"><say-as interpret-as="digits">5498</say-as></prosody>.
        5. The number is: 5498.
    </speak>

或将@OneToMany(mappedBy = "author") private List<PostEntity> answers; 字段移至AnswerEntity。