Hibernate一对一关联（唯一外键）

在一对一关系中，两个表通过外键关联，但是只有一个外键！

package com.pojo;
public class User implements java.io.Serializable {
	private static final long serialVersionUID = 3877915998065689256L;
	private Long id;
	private String username;
	private String password;
	//一对一关联
	private Profile profile;
	public Profile getProfile() {
		return profile;
	}
	public void setProfile(Profile profile) {
		this.profile = profile;
	}
	public User() {
	}
	public Long getId() {
		return this.id;
	}
	public void setId(Long id) {
		this.id = id;
	}
	public String getUsername() {
		return this.username;
	}
	public void setUsername(String username) {
		this.username = username;
	}
	public String getPassword() {
		return this.password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
}

package com.pojo;
public class Profile implements java.io.Serializable {
	private static final long serialVersionUID = -9070015557361756382L;
	private Long id;
	private String email;
	private String phone;
	private String address;
	//关联User
	private User user;
	public User getUser() {
		return user;
	}
	public void setUser(User user) {
		this.user = user;
	}
	public Profile() {
	}
	public Long getId() {
		return this.id;
	}
	public void setId(Long id) {
		this.id = id;
	}
	public String getEmail() {
		return this.email;
	}
	public void setEmail(String email) {
		this.email = email;
	}
	public String getPhone() {
		return this.phone;
	}
	public void setPhone(String phone) {
		this.phone = phone;
	}
	public String getAddress() {
		return this.address;
	}
	public void setAddress(String address) {
		this.address = address;
	}
}

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- 
    Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping>
    <class name="com.pojo.User" table="USERS" schema="ZM">
        <id name="id" type="java.lang.Long">
            <column name="ID" precision="4" scale="0" />
            <generator class="increment"></generator>
        </id>
        <property name="username" type="java.lang.String">
            <column name="USERNAME" length="100" />
        </property>
        <property name="password" type="java.lang.String">
            <column name="PASSWORD" length="100" />
        </property>
        
        <!-- 一对一关联 -->
        <one-to-one name="profile" class="com.pojo.Profile"></one-to-one>
    </class>
</hibernate-mapping>

唯一外键的配置：

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- 
    Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping>
    <class name="com.pojo.Profile" table="PROFILE" schema="ZM">
        <id name="id" type="java.lang.Long">
            <column name="ID" precision="4" scale="0" />
            <generator class="increment" />
        </id>
        <property name="email" type="java.lang.String">
            <column name="EMAIL" length="100" />
        </property>
        <property name="phone" type="java.lang.String">
            <column name="PHONE" length="100" />
        </property>
        <property name="address" type="java.lang.String">
            <column name="ADDRESS" length="100" />
        </property>
        
        <!-- 唯一外键 -->
        <many-to-one name="user" class="com.pojo.User" unique="true">
        <!-- column都是指数据库中的字段 -->
        <column name="user_id"></column>
        </many-to-one>
        
        
    </class>
</hibernate-mapping>