保存实体后 Spring Boot Jpa 获取关系不起作用

Question

I have a project with spring boot and hibernate.Everything working well with select data from database but I have a problem after insert entities. Entity relations not fetch after insert. I tried JpaRepository saveAndFlush but didn't work.Also I tried findById didn't work . How can I solve this problem ?

My Entity;

@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;
}

My Repository;

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

My Service Method;

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);
    }

My Controller; using saveOneComment endpoint

@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, users=null, post=null) After insert and find again, users and post is null. When I run getAllCommentsByPostId method everything is fine.

after insert only insert query in console.There is not any query for select statement.

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

Answer 1

you have to reload the object again after committing the transaction, i mean outside the transaction to maintain the relations

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