Question

我试图实现@ManyToMany关系，但我的联接表未被填充。我的应用程序为竞争对手的对象建模了一堆竞争对象。有一群竞争对手。在该组中，每个竞争者彼此匹配以形成竞赛。因此每个比赛都可以有一个竞争对手的对象列表。每个参赛者都可参加多场比赛。

实体对象

比赛看起来像这样：

@Entity
@Table(name = "competition")
public class Competition implements java.io.Serializable {

    @Id
    @GeneratedValue
    private int competitionId;

    @ManyToMany(cascade = CascadeType.ALL)
    @JoinTable(name = "competition_competitors", joinColumns = @JoinColumn(name = "competitionId"), inverseJoinColumns = @JoinColumn(name = "competitorId"))
    private Set<Competitor> competitors = new TreeSet<Competitor>();

            . . .

我的竞争对手看起来像这样：

@Entity
@Table(name = "competitor")
public class Competitor implements Comparable<Competitor>, java.io.Serializable {

    @Id
    @GeneratedValue
    private int competitorId;

    @ManyToMany(mappedBy = "competitors", cascade = CascadeType.ALL)
    private Set<Competition> competitions = new TreeSet<Competition>();

            . . .

竞争服务方法

@Override
@Transactional(readOnly = false)
public Competition createCompetition(League league, Competitor competitor1, Competitor competitor2) {
    Competition competition = getCompetitionDAO().create(league);
    competition.add(competitor1);
    competition.add(competitor2);
    this.competitionDao.saveOrUpdate(competition);
    return competition;
}

CompetitionDAO方法

@Override
@Transactional(readOnly = false)
public void saveOrUpdate(Competition competition) {
    if (competition != null) {
        Session session = getCurrentSession();
        try {
            session.saveOrUpdate(competition);
        } catch (Exception exception) {
            throw new AppException(exception);
        }
    }
}

申请代码

此代码应创建竞争并坚持下去。它过去常常这样做，但在某个地方，我打破了它，它不再将任何东西保存到连接表{competition_competitors}。

@Transactional(readOnly = false)
private void createLeague(LeagueData leagueData) {

    User user = createAccount( ... );
    League league = createLeague(user, leagueData.getLeagueName());

    for (int index = 0; index < leagueData.getCompetitorNames().length; index++) {
        Competitor competitor = this.serviceProvider.getCompetitorService().find(league, leagueData.getCompetitorNames()[index]);
        if (competitor == null) {
            competitor = createCompetitor(league, leagueData.getCompetitorNames()[index], leagueData.getCompetitorDescription()[index]);
        }
        this.serviceProvider.getCompetitionService().createCompetition(league, competitor);
    }
}

问题：关于为什么在应用程序运行时没有填充连接表的任何想法？应用程序代码运行时没有错误。我不明白为什么单元测试工作正常并填充连接表，但类似的应用程序代码没有。

Answer 1

如果你看不到MySQL Workbench中出现的值，但你的单元测试正在通过，那是因为Spring在单元测试完成后会自动回滚事务。因此，如果您可以在提交事务的确切时刻立即刷新MySQL Workbench，那么您将在事务回滚之前看到您的值约0.2毫秒并且值丢失。

您的联接表正在运行，否则您的断言将失败。

Answer 2

Spring在测试用例结束后回滚事务。要避免回滚行为，请在测试类上使用@TransactionConfiguration(defaultRollback = false)注释。

Hibernate @ManyToMany - 未填充连接表

2 个答案: