@Entity
@Table(name="Instructor")
public class Instructor {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name="id")
private int id;
@OneToOne(cascade = CascadeType.ALL)
@JoinColumn(name = "detail_id")
private InstructorDetails detail;
@Column(name="name")
private String name;
}
这是我的第一个实体类,这个类确实包含所需的 setter、getter 和构造函数,我没有包括它们,因为它们会使问题变得冗长
@Entity
@Table(name="InstructorDetails")
public class InstructorDetails {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "did")
private int did;
@OneToOne(mappedBy = "detail",cascade = CascadeType.ALL)
private Instructor instructor;
@Column(name = "address")
private String address;
@Column(name = "course")
private String course;
@Column(name = "hobby")
private String hobby;
@Column(name = "dept")
private String dept;
}
这是我的第二个实体类,这个类确实包含所需的 setter、getter 和构造函数,我没有包括它们,因为它们会使问题变得冗长
如您所见,我已尝试执行双向一对一映射,
我已经清楚地提到了 cascade=CascadeType.ALL
,这意味着发生在一个表中的所有操作都级联到另一个表中,我试图通过包含 @OneToOne(mappedBy = "detail", cascade = CascadeType.ALL)
这里的问题是
Session session = sf.getCurrentSession();
session.beginTransaction();
InstructorDetails detail=new InstructorDetails("bengaluru", "Java", "Guitar", "development");
Instructor instructor=new Instructor("john",detail);
session.save(instructor);
session.getTransaction().commit();
此代码将详细信息同时推送到 Instructor
和 InstructorDetails
表中,但如果
Session session = sf.getCurrentSession();
session.beginTransaction();
Instructor instructor=new Instructor();
instructor.setName("Sam");
InstructorDetails detail=new InstructorDetails("bengaluru", "Java", "Guitar", "development");
detail.setInstructor(instructor);
session.save(detail);
session.getTransaction().commit();
此代码仅将数据推送到 InstructorDetails
表中,Instructor
表未更新教师详细信息,这意味着映射是单向的
Instructor
上的所有 CRUD 操作都级联到 InstructorDetails
,但我无法实现反之亦然,请在这里帮助我,我如何确保 InstructorDetails
上执行的所有 CRUD 操作{1}} 也会影响 Instructor
答案 0 :(得分:1)
正如它在休眠documentation中所述:
<块引用>无论何时形成双向关联,应用程序开发人员都必须确保双方始终保持同步。
因此,您应该通过以下方式更正您的代码:
Session session = sf.getCurrentSession();
session.beginTransaction();
Instructor instructor = new Instructor();
instructor.setName("Sam");
InstructorDetails detail = new InstructorDetails("bengaluru", "Java", "Guitar", "development");
// sync both side of association
detail.setInstructor(instructor);
instructor.setDetail(detail);
session.save(detail);
session.getTransaction().commit();