Java JPA/Hibernate:已创建表的注释
我有两个表(已经创建),比如Person和Address,具有以下模式:Java JPA/Hibernate:已创建表的注释,java,hibernate,jpa,Java,Hibernate,Jpa,我有两个表(已经创建),比如Person和Address,具有以下模式: 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
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`)
)
现在,我应该在代码中使用哪些注释
这两个类别的骨架是:
class Person {
@Id @GeneratedValue
@Column(name="id")
int id;
String name;
Address address;
}
class Address {
int id;
}
我需要在Person.java中为Person类中的address字段和address类的id字段添加注释
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;
}
@OneToOne(cascade = CascadeType.ALL, fetch = FetchType.LAZY)
@JoinColumn(name = "id",nullable=false)
@ForeignKey(name = "fk_id")
private Address address;
在Address.java中-
@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;
我想你想用
查看文档中的示例2。人员id和地址id始终相同是否正确?是。实际上,Person和Address具有一对一的关系。不确定这是否有效,因为SchemaWeb中没有Address\u id列。Address类中的id字段可以有列名“Address\u id”。它会工作吗?@JoinColumn(name=“address\u id”,referencedColumnName=“id”)表示person表中的address\u id列将引用address表中的id列,但您需要在person表中创建address\u id列。谢谢,但我无法在address类中添加person字段。此处person代表id。我已修改了示例,您可以再次查看此示例。在这里,我为一列创建了两个映射。一个将返回id,另一个将返回Person对象。
@Entity
class Person {
@Id
@GeneratedValue
int id;
String name;
@OneToOne
@MapsId
Address address;
}
@Entity
class Address {
@Id
int id;
}