JPA / Hibernate：已创建表的批注

Question

I have two tables (already created), say Person and Address with following schemas:

create table Person (
    `id` int(11) not null auto_increment,
    `name` varchar(255) default null,
    primary key(`id`)
)

create table Address (
    `id` int(11) not null,
    `city` varchar(255) default null,
    primary key (`id`),
    constraint foreign key (`id`) references `Person`(`id`)
)

Now, which annotations should I use in the code?

The skeletons of both the classes are:

class Person {
    @Id @GeneratedValue
    @Column(name="id")
    int id;
    String name;

    Address address;
}

class Address {
    int id;
}

I need to add annotations for address field in Person class and id field of Address class.

Answer 1

in Person.java

@OneToOne(cascade = CascadeType.ALL, fetch = FetchType.LAZY)
@JoinColumn(name = "id",nullable=false)
@ForeignKey(name = "fk_id")     
private Address address;   

and in Address .java -

@OneToOne(fetch=FetchType.LAZY)
@JoinColumn(name = "id", updatable = false, insertable = false, nullable=false)  
private Person id;    

@Column(name = "id", insertable = false, updatable = false, nullable=false)
private Integer id;

Answer 2

 class Person {
   @Id @GeneratedValue
   @Column(name="id")
   int id;
   String name;

   @OneToOne
   @JoinColumn(name = "address_id", referencedColumnName = "id")
   Address address;
}

class Address {
    @id
    int id;
}

Answer 3

I think you want to use @MapsId .

@Entity
class Person {
   @Id 
   @GeneratedValue
   int id;

   String name;

   @OneToOne 
   @MapsId
   Address address;
}

@Entity
class Address {
    @Id
    int id;
}

Check out example 2 in the @OneToOne documentation.