JPA 映射具有两个 @OneToOne 关系的体育游戏

Question

我的足球比赛有以下层次结构。

@Entity
public class Match {
    @Id
    @GeneratedValue
    protected Integer id;

    @Column(name = "home_team_id")
    private int homeTeamId;

    @Column(name = "away_team_id")
    private int awayTeamId;

    private TeamScore homeScore;

    private TeamScore awayScore;
}

@Entity(name = "team_score")
public class TeamScore  {
    @EmbeddedId
    protected TeamScoreId id;

    private List<Goal> goals;
}

@Embeddable
public class TeamScoreId {
    @Column(name = "match_id")
    private Integer matchId;

    @Column(name = "team_id") 
    private int teamId;
}

我在将比赛中的 homeScore 和awayScore 与 TeamScore 实体映射时遇到问题。 第一个关心的是两个 @OneToOne 关系是否应该在这里。以及应该如何配置它们？ 第二个与 TeamScoreId 中的 matchId 相关。如何执行此映射？

Answer 1

首先关心的是两个@OneToOne关系是否应该在这里。又该如何配置呢？

是的，我们应该为 TeamScore 进行一对一的配置。

第二个与TeamScoreId中的matchId有关。如何执行此映射？ 该映射在没有注释的情况下以一对一的方式执行。

以 Java 代码保存的示例数据如下

session.persist(Match.builder()
        .homeTeamId(1)
        .awayTeamId(2)
        .awayScore(TeamScore.builder()
                .id(TeamScoreId.builder()
                        .matchId(1)
                        .teamId(1)
                        .build())
                .goals(List.of(Goal.builder()
                        .score(1)
                        .build()))
                .build())
        .homeScore(TeamScore.builder()
                .id(TeamScoreId.builder()
                        .matchId(2)
                        .teamId(2)
                        .build())
                .goals(List.of(Goal.builder()
                        .score(2)
                        .build()))
                .build())
        .build());

它会生成如下所示的团队得分数据

我改变了如下的课程

@Entity
@Data
@Builder
@AllArgsConstructor
@NoArgsConstructor
public class Match {
    @Id
    @GeneratedValue
    protected Integer id;

    @Column(name = "home_team_id")
    private int homeTeamId;

    @Column(name = "away_team_id")
    private int awayTeamId;

    @OneToOne(cascade = CascadeType.ALL)
    private TeamScore homeScore;
    @OneToOne(cascade = CascadeType.ALL)
    private TeamScore awayScore;
}

@Entity
@Data
@Builder
@AllArgsConstructor
@NoArgsConstructor
public class Goal implements Serializable {
    @Id
    @GeneratedValue
    private Long id;
    private int score;
    @CreationTimestamp
    Instant createDate;
}

@Entity(name = "team_score")
@Builder
@AllArgsConstructor
@NoArgsConstructor
public class TeamScore implements Serializable {
    @EmbeddedId
    protected TeamScoreId id;
    @OneToMany(cascade = CascadeType.ALL)
    private List<Goal> goals;
}

@Embeddable
@Builder
@AllArgsConstructor
@NoArgsConstructor
public class TeamScoreId implements Serializable {
    @Column(name = "match_id")
    private Integer matchId;
    @Column(name = "team_id")
    private int teamId;
}

在此处查找完整的工作示例。