保存实体后，Hibernate对于以@Formula注释的实体属性返回null

Question

我有一个简单的类，如下所示：

@Entity

@Table(name = "post")

public class Post {

    @Id

    @GeneratedValue

    Long id;

    @Column(name = "title")

    String title;

    @Formula("(select current_date())")

    Date currentDate;

    @OneToMany(mappedBy = "post")

    Set<PostComment> commentList = new HashSet<>();

}

并希望在服务中更新此实体：

@Service

@Transactional

public class PostService {

    private final PostRepository postRepository;

    public PostService(PostRepository postRepository) {

        this.postRepository = postRepository;

    }

    @Transactional

    public Post save(Post entity) {

        Post post = postRepository.saveAndFlush(entity);

        System.out.println("current_date: " + post.getCurrentDate());

        post.getCommentList().forEach(pc -> System.out.println(pc.getReview()));

        return post;

    }

}

当我检查休眠日志时，它首先select是Post实体的所有字段，但是当我调用post.getCurrentDate()（用注释@Formula）时返回null：

Hibernate: select post0_.id as id1_0_0_, post0_.title as title2_0_0_, (select current_date()) as formula0_0_ from post post0_ where post0_.id=?

Hibernate: update post set title=? where id=?

current_date: null

Hibernate: select commentlis0_.post_id as post_id3_1_0_, commentlis0_.id as id1_1_0_, commentlis0_.id as id1_1_1_, commentlis0_.post_id as post_id3_1_1_, commentlis0_.review as review2_1_1_ from post_comments commentlis0_ where commentlis0_.post_id=?

review

为什么返回并记录commentList但不返回currentDate？是冬虫吗？