Question

我正在学习JPA（2.1）和Hibernate（5.0.4）。在@OneToOne关系映射练习的情况下，我想基于生成的共享键序列创建单向映射。我能够双向进行。

我能够使用[this blog]完成它，但它看起来像 hack （下面的代码）有没有更好的方法来映射这种情景？

DDL：

DROP TABLE HIBERNATE.T_USER_DETAILS;
DROP TABLE HIBERNATE.T_USERS;
DROP SEQUENCE HIBERNATE.USERS_SEQ;

-- ON HIBERNATE
CREATE TABLE HIBERNATE.T_USERS (
  ID                                NUMBER(15),
  NAME                              VARCHAR2(100 CHAR),
  CONSTRAINT USER_PK PRIMARY KEY (ID)
);

CREATE TABLE HIBERNATE.T_USER_DETAILS (
  ID                                NUMBER(15),
  DETAILS                           VARCHAR2(100 CHAR),
  CONSTRAINT UDETAILS_PK PRIMARY KEY (ID),
  CONSTRAINT UDETAILS_FK FOREIGN KEY (ID) REFERENCES T_USERS(ID)
);

CREATE SEQUENCE HIBERNATE.USERS_SEQ START WITH 1 INCREMENT BY 1 NOCACHE NOCYCLE;

的usermodel：

@Entity
@Table(name = "T_USERS")
@SequenceGenerator(name = "users-sequence-generator", sequenceName = "USERS_SEQ", initialValue = 0, allocationSize = 1)
public class UserModel {

    private Long id;
    private String name;
    private UserDetailsModel userDetails;

    @Id
    @Column(name = "id")
    @GeneratedValue(generator = "users-sequence-generator", strategy = GenerationType.SEQUENCE)
    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
        if (userDetails != null) {
            userDetails.setId(id);
        }
    }

    @Column(name = "name")
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @OneToOne(fetch = EAGER, cascade = ALL)
    @JoinColumn(name = "id", insertable = false, updatable = false)
    public UserDetailsModel getUserDetails() {
        return userDetails;
    }

    public void setUserDetails(UserDetailsModel userDetails) {
        this.userDetails = userDetails;
    }
}

UserDetailsModel：

@Entity
@Table(name = "T_USER_DETAILS")
public class UserDetailsModel {

    @Id
    @Column(name = "id")
    private Long id;

    @Column(name = "details")
    private String details;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getDetails() {
        return details;
    }

    public void setDetails(String details) {
        this.details = details;
    }

}

@OneToOne单向共享主键

0 个答案: