Question

我想在“地址”实体中保存“用户”和“雇员”实体的地址。如何设计我的地址实体，以便能够保存用户和雇员的地址。

Answer 1

使用地址实体作为成员创建一个抽象基类Person。

在“用户”和“员工”子类中扩展“人”类。

@MappedSuperclass
abstract class Person {
    @ManyToOne @JoinColumn(name="ADDRESS")
    protected Address address;
}

@Entity
class Employee extends Person {}

@Entity
class User extends Person {}

Answer 2

您有两种选择，一种是使地址实体可嵌入，

@Embeddable
public class Address {
   ....
}

@Entity
public class User {
     .....
    @Embedded
    private Address address;

}

@Entity
public class Employee {
     .....
    @Embedded
    private Address address;

}

这将复制表Employee和表User中的列。

如果要共享地址，另一种方法是将地址用作表格：

@Entity
public class Address {
   ....
}

@Entity
public class User {
     .....
    @ManyToOne
    private Address address;

}

@Entity
public class Employee {
     .....
    @ManyToOne
    private Address address;

}

实体的休眠映射字段作为多个实体的外键

2 个答案: