如何使用外键将两个表映射到一个实体？

Question

CREATE TABLE CUSTOMER
(
    CUSTOMER_ID INTEGER NOT NULL,
    DETAIL_ID INTEGER NOT NULL,
    PRIMARY KEY( CUSTOMER_ID ),
    CONSTRAINT cust_fk FOREIGN KEY( DETAIL_ID ) REFERENCES DETAILS( DETAIL_ID )
)

CREATE TABLE DETAILS
(
    DETAIL_ID INTEGER NOT NULL,
    OTHER INTEGER NOT NULL,
    PRIMARY KEY( DETAIL_ID )
)

@Entity
@Table(name = "CUSTOMERS")
@SecondaryTable(name = "DETAILS", pkJoinColumns=@PrimaryKeyJoinColumn(name="DETAIL_ID"))
public class Customer {
    @Id
    @GeneratedValue
    @Column(name = "CUSTOMER_ID")
    private Integer id;

   @Column(table = "DETAILS", name = "OTHER")
   private Integer notes;

   // ...
}

@secondarytable(name=“details”,pkjoincolumns=@primarykeyjoincolumn(name=“detail_id”,referencedcolumnname=“detail_id”））

但是当我运行应用程序时，我会得到以下异常：

org.hibernate.mappingException：在org.hibernate.mapping.table(CUSTOMERS)及其相关的超表和辅助表中找不到逻辑名为:DETAIL_ID的列

Answer 1

对于任何正在寻找答案的人来说，使用@secondarytable不是连接两个具有非主键列的表的方法，因为默认情况下Hibernate会尝试通过主键将这两个表归类；您必须使用@onetomany review http://viralpatel.net/blogs/hibernate-one-to-many-annotation-tutorial/来获得解决方案，以下是url停止工作时的代码片段：

客户类别：

@Entity
@Table(name="CUSTOMERS")
public class Customer {

    @Id
    @GeneratedValue
    @Column(name="CUSTOMER_ID")
    private Integer id;

    @ManyToOne
    @JoinColumn(name="DETAIL_ID")
    private Details details;

    // Getter and Setter methods...
}

详细信息类：

@Entity
@Table(name="DETAILS")
public class Details {

    @Id
    @GeneratedValue
    @Column(name="DETAIL_ID")
    private int detailId;

    @Column(name="OTHER")
    private String other;

    @OneToMany(mappedBy="details")
    private Set<Customer> customers;

    // Getter and Setter methods...
}

Session session = HibernateUtil.getSessionFactory().openSession();
Query query = session.createQuery("select id, details.other from Customer");