인프런 커뮤니티 질문&답변

import java.time.LocalDateTime;
import java.util.ArrayList;
import java.util.List;

import jakarta.persistence.CascadeType;
import jakarta.persistence.Column;
import jakarta.persistence.Entity;
import jakarta.persistence.GeneratedValue;
import jakarta.persistence.GenerationType;
import jakarta.persistence.Id;
import jakarta.persistence.OneToMany;
import jakarta.persistence.Table;
import lombok.AccessLevel;
import lombok.Builder;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;

@Entity
@Table(name = "tb_board")
@NoArgsConstructor(access = AccessLevel.PUBLIC)
@Getter
@Setter
public class Board {

	@Id
	@GeneratedValue(strategy = GenerationType.IDENTITY)
	@Column(name = "BOARD_ID",  columnDefinition = "BIGINT COMMENT '게시판ID'")
	private Long id;

	@Column(name = "BOARD_NM", nullable = false, unique = true, length = 100, columnDefinition = "VARCHAR(100) COMMENT '게시판명'")
	private String boardNm;
	
	@OneToMany(mappedBy = "board", cascade = CascadeType.ALL, orphanRemoval = true)
	private List<Article> articleList = new ArrayList<Article>();
	
	@Builder
	private Board(Long boardId, String boardNm) {
		this.boardNm= boardNm;
		this.id = boardId;
	}
	
	public Board createBoard(Long boardId, String boardNm) {
		return Board.builder().boardId(boardId).boardNm(boardNm).build();
	}
	
	public void addArticle(Article article) {
		this.articleList.add(article);
	}
	
	
	@Column(name="REG_ID" ,nullable=false,columnDefinition="VARCHAR(100) comment '등록자'")
	private String regId;
	
	
	@Column(name = "CREATED_AT", columnDefinition = "TIMESTAMP DEFAULT CURRENT_TIMESTAMP")
	private LocalDateTime createdAt;
	
	@Column(name="UPD_ID" ,nullable=false,columnDefinition="VARCHAR(100) comment '등록자'")
	private String updId;
	
	@Column(name = "UPDATED_AT", columnDefinition = "TIMESTAMP DEFAULT CURRENT_TIMESTAMP")
	private LocalDateTime updatedAt;
	
	
}

@Entity
@Table(name = "tb_article")
@Builder
@Getter
@Setter
@AllArgsConstructor
@NoArgsConstructor
 public class Article {
	@Id
	@GeneratedValue(strategy = GenerationType.IDENTITY)
	@Column(name = "ARTICLE_ID", columnDefinition = "BIGINT COMMENT '게시글ID'")
	private Long id;

	@Column(name = "ARTICLE_TITLE", columnDefinition = "VARCHAR(100) COMMENT '게시글제목'")
	private String title;

	@Column(name = "ARTICLE_CONTENT", columnDefinition = "VARCHAR(600) COMMENT '게시글내용'")
	private String content;

	@Column(name = "REG_ID", nullable = false, columnDefinition = "VARCHAR(100) comment '등록자'")
	private String regId;

	@Column(name = "CREATED_AT", columnDefinition = "TIMESTAMP DEFAULT CURRENT_TIMESTAMP")
	private LocalDateTime createdAt;

	@Column(name = "UPD_ID", nullable = false, columnDefinition = "VARCHAR(100) comment '등록자'")
	private String updId;

	@Column(name = "UPDATED_AT", columnDefinition = "TIMESTAMP DEFAULT CURRENT_TIMESTAMP")
	private LocalDateTime updatedAt;

	@ManyToOne
	@JoinColumn(name = "BOARD_ID", nullable = false)
	private Board board;

}

 @Transactional(rollbackFor = Exception.class)  // 체크 예외도 롤백
     public void saveArticle(Article article) {
		try {
			log.info("article",article.getTitle());
 			Long boardId = 13L;
 			Board paramBoard = null;
			Optional<Board> rBoard = boardRepository.findById(boardId);
			if(rBoard.isPresent()) {
				paramBoard =rBoard.get();
			}else {
				paramBoard = new Board().createBoard(boardId, "게시판");
				paramBoard = boardRepository.save(paramBoard);
 			}
 			Article paramArticle = Article.builder()
                                               .title(article.getTitle())
                                               .content(article.getContent())
                                               .regId("등록자")
                                               .createdAt(LocalDateTime.now())
                                               .updatedAt(LocalDateTime.now())
                                               .board(paramBoard)
                                               .updId("수정자")
                                               .build();
			
			if(paramBoard.getArticleList() == null) {
				List<Article> articles =new ArrayList<Article>();
				articles.add(paramArticle);
				paramBoard.setArticleList(articles);
			}else {
				paramBoard.getArticleList().add(paramArticle);
			} 
			
			boardRepository.save(paramBoard);
			
		}catch(Exception ex) {
	        log.error("Error saving article", ex);
			throw ex;
		}
		
	}

else {
 paramBoard = new Board().createBoard(boardId, "게시판");
 paramBoard = boardRepository.save(paramBoard);
 			}
여기서 save를 돌떄 
org.springframework.orm.ObjectOptimisticLockingFailureException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect): [com.backend.com.entity.Board#13]
	at org.springframework.orm.jpa.vendor.HibernateJpaDialect.convertHibernateAccessException(HibernateJpaDialect.java:325) ~[spring-orm-6.2.2.jar:6.2.2]
	at org.springframework.orm.jpa.vendor.HibernateJpaDialect.translateExceptionIfPossible(HibernateJpaDialect.java:244) ~[spring-orm-6.2.2.jar:6.2.2]
	요런식으로 뜨는데

해본 방법

1. boardRepository.save(paramBoard) 부분을 빼고 마지막
   boardRepository.save(paramBoard);

    

만 돌려봤지만 마찬가지 에러가 발생했었고

1. 혹시 table 쪽에 lock이 걸려있나 싶어서 보니 lock도 없었음

3. 지피티 한테 물어보니깐
@Lock(LockModeType.PESSIMISTIC_WRITE)
쓰라고 해서 save쪽에 넣어봄 . 마찬가지 ..

Board쪽에
@Version @Column(name = "version") private Long version;
을 추가하라고 해서 추가해봐도 마찬가지 ..

이유는
"Row was updated or deleted by another transaction" 오류는 동시에 여러 트랜잭션에서 동일한 데이터를 수정하거나 삭제할 때 발생할 수 있습니다. 즉, 한 트랜잭션에서 데이터를 수정하는 동안 다른 트랜잭션에서 동일한 데이터를 수정하거나 삭제했기 때문에 충돌이 발생하는 것

이라는데 잘 모르겠습니다 뭐가 문제일까요 .

public interface BoardRepository extends JpaRepository<Board, Long>, QuerydslPredicateExecutor<Board> {
	Optional<Board> findById(Long boardId);
}

querydsl과 jpa같이 사용하고싶어서 셋팅한거 입니다.