Spring Boot Jpa在保存实体后获取关系不工作

Question

我有一个关于spring boot和hibernate的项目。从数据库中选择数据时一切正常，但在插入实体后我遇到了一个问题。插入后未提取实体关系。我尝试了JpaRepository保存并刷新，但没有成功。此外，我还尝试了findById，但没有成功。我如何解决这个问题？

我的实体；

@Entity
@Table(name = "Comment")
@Data
@ApiModel(value = "Comment Model")
public class Comment {

 public static  Comment createCommentFromCommentPostRequest(CommentPostRequest commentPostRequest){
     Comment comment = new Comment();
     comment.setPostId(commentPostRequest.getPostId());
     comment.setUsersId(commentPostRequest.getUsersId());
     comment.setText(commentPostRequest.getText());
     return  comment;
 }

 @Id
 @GeneratedValue(strategy = GenerationType.IDENTITY)
 @Column(name = "id")
 @ApiModelProperty(value = "Comment model autogenerated Id value")
 private Long id;

 @Column(name = "usersId",nullable = false)
 @ApiModelProperty(value = "User Id for describe who commented post")
 private Long usersId;

 @Column(name = "postId",nullable = false)
 @ApiModelProperty(value = "Post Id for describe which post commented")
 private Long postId;

 @Column(name = "text",length = 500)
 @ApiModelProperty(value = "define post content")
 private String text;

 @ManyToOne(fetch = FetchType.EAGER)
 @Fetch(FetchMode.JOIN)
 @JoinColumn(name = "usersId",insertable = false,updatable = false,nullable = false)
 private Users users;

 @ManyToOne(fetch = FetchType.EAGER)
 @JoinColumn(name = "postId",insertable = false,updatable = false,nullable = false)
 @JsonIgnore
 @OnDelete(action = OnDeleteAction.CASCADE)
 private Post post;
}

我的存储库；

public interface CommentRepository extends PagingAndSortingRepository<Comment,Long> {
    List<Comment> findAllByPostId(Long postId, Pageable pageable);
}

我的服务方式；

public Comment saveOneComment(CommentPostRequest commentPostRequest) {
        //TODO: implement validation
        Comment commentToSave = Comment.createCommentFromCommentPostRequest(commentPostRequest);
        commentToSave= commentRepository.save(commentToSave);
        //I tried JPA repository saveAndFlush 
        return commentRepository.findById(commentToSave.getId()).orElse(null);
    }

我的控制器；使用saveOneCommentendpoint

@RestController
@RequestMapping("/api/comment")
@ApiOperation(value = "Comment api controller")

public class CommentController {

    CommentService commentService;

    public CommentController(CommentService commentService) {
        this.commentService = commentService;
    }

    @GetMapping("/{pageNo}/{pageSize}")
    public List<Comment> getAllComments(@PathVariable int pageNo,@PathVariable int pageSize){

        return Streamable.of(commentService.getAllComments(pageNo,pageSize)).toList();
    }

    @GetMapping("/{commentId}")
    public Comment findCommentById(@PathVariable Long commentId){
        return commentService.findById(commentId);
    }

    @GetMapping("/postId={postId}/{pageNo}/{pageSize}")
    public List<CommentResponse> getAllCommentsByPostId(@PathVariable Long postId,@PathVariable int pageNo,@PathVariable int pageSize){
        return commentService.getAllCommentsByPostIdAsCommentResponse(postId,pageNo,pageSize);
    }

    @PostMapping
    public Comment saveOneComment(@RequestBody CommentPostRequest commentPostRequest){

        return commentService.saveOneComment(commentPostRequest);
    }

    @PutMapping("/{commentId}")
    public Comment putOneComment(@PathVariable Long commentId,@RequestBody CommentPostRequest commentPostRequest){
        return commentService.putOneCommentById(commentId,commentPostRequest);
    }

    @DeleteMapping("/{commentId}")
    public void deleteOneComment(@PathVariable Long commentId){
        commentService.deleteById(commentId);
    }
}

Comment（id=32， usersId=2， postId=2， text=ddwad， user=null， post=null）再次插入并查找后，用户和post为空。当我运行getAllCommentsByPostId方法时一切正常。

插入后，仅在控制台中插入查询。select语句没有任何查询。

 insert 
    into
        Comment
        (postId, text, usersId) 
    values
        (?, ?, ?)

Answer 1

您必须在提交事务后重新加载对象，我的意思是在事务外部维护关系

  @PostMapping
 public Comment saveOneComment(@RequestBody CommentPostRequest commentPostRequest){
      
             Long id= commentService.saveOneComment(commentPostRequest);
        return commentService.loadCommentById(id);
    }
    ````