Person与Address关联：双向1->1,【基于外键的】。
#主表不应该控制关联关系。（否则会导致生成额外的update语句，从而导致性能下降），
#因此主表对应的实体中使用@OneToOne注解时，应该增加mappedBy属性。
Person.java
package org.crazyit.app.domain;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.OneToOne;
import javax.persistence.Table;
@Entity
@Table(name = "Person_inf")
public class Person {
@Column(name = "person_id")
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
private String name;
private Integer age;
// 双向1->1:对关联关系
// 定义该Person实体所有关联的Address
@OneToOne(targetEntity = Address.class, mappedBy = "person")
private Address address;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Address getAddress() {
return address;
}
public void setAddress(Address address) {
this.address = address;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
}
Address.java
package org.crazyit.app.domain;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToOne;
import javax.persistence.Table;
@Entity
@Table(name = "Address_inf")
public class Address {
@Id
@Column(name = "address_id")
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
// 定义该Address实体关联的person实体
@OneToOne(targetEntity = Person.class)
// 用于映射person_id外键列，参照person_inf表的person_id列
// 指定unique=true,表名是1-1关联
@JoinColumn(name = "person_id", //
referencedColumnName = "person_id", //
unique = true) // 唯一性约束（unique）
private Person person;
// 地址详细
private String addressDetail;
// 无参构造方法
public Address() {
}
// 初始化全部成员变量
public Address(String addressDetail) {
this.addressDetail = addressDetail;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getAddressDetail() {
return addressDetail;
}
public void setAddressDetail(String addressDetail) {
this.addressDetail = addressDetail;
}
public Person getPerson() {
return person;
}
public void setPerson(Person person) {
this.person = person;
}
}
#数据模型
