相关疑难解决方法(0)

我正在尝试使用复合主键在学生和教学课程之间创建许多非常多的关系:

我的课程:

@Entity
@Table(name="Student_mtm_cId")
public class Student {

    private String id;
    private Set<StudentTClass> teachingClasses = new HashSet<StudentTClass>();

    @OneToMany(fetch = FetchType.LAZY, mappedBy = "pk.student")
    public Set<StudentTClass> getTeachingClasses() {
        return teachingClasses;
    }
    public void setTeachingClasses(Set<StudentTClass> teachingClasses) {
        this.teachingClasses = teachingClasses;
    }

    public void addStudentToClass(TeachingClass teachingClass){
        StudentTClass studentTClass = new StudentTClass();
        studentTClass.setStudent(this);
        studentTClass.setTeachingClass(teachingClass);
        teachingClasses.add(studentTClass);
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    @Id @GeneratedValue(generator="system-uuid")
    @GenericGenerator(name="system-uuid", strategy = "uuid")
     @Column(name = "student_id", nullable = false)
    public String getId() {
        return id;
    } …

@Autowired
private SessionFactory sessionFactory;
public String getAccountsDetails(List<Account> accountList) {
    Session session = sessionFactory.openSession();
    for (Account account : accountList) {
        int i = 0;
        AccountDetails accountDetails = new AccountDetails();
        accountDetails.setAccountsId(Long.parseLong(account.getId()));//LINE no -20
        accountDetails.setName(account.getName());
        accountDetails.setSubAccount(account.getAccountSubType());
        session.saveOrUpdate(accountDetails);
        if (++i % 20 == 0) {
            session.flush();  
            session.clear();  
        } 
    }
        session.getTransaction().commit();
        session.close();
}

输出：

即使数据库中没有数据，它也会始终运行更新。

   Hibernate: update name=?, subaccount=? where accounts_id=?
    ....

如果我在第 20 行中评论帐户 ID，它总是运行插入。

Hibernate：插入表测试......

dto类：

@Entity
@Table(name="test")
public class AccountDetails{
    @Id
    @GeneratedValue
    @Column(name = "accounts_id")
    private Long accountsId;

    @Column(name = "name")
    private …