hibernate---一对一双向外键关联 (重要)

husband--wife: one to one 双向外键关联:

主导方:

@OneToOne

@JoinColumn(name="wifeId")

被主导方: @OneToOne(mappedBy="wife")

1. husband.java:

package com.bjsxt.hibernate;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToOne;

@Entity
public class Husband {
	private int id;
	private String name;
	private Wife wife;
	@Id
	@GeneratedValue
	public int getId() {
		return id;
	}
	
	public String getName() {
		return name;
	}
	@OneToOne
	@JoinColumn(name="wifeId")
	public Wife getWife() {
		return wife;
	}
	public void setId(int id) {
		this.id = id;
	}
	public void setName(String name) {
		this.name = name;
	}
	public void setWife(Wife wife) {
		this.wife = wife;
	}
	
}

wife.java:

package com.bjsxt.hibernate;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.OneToOne;

@Entity
public class Wife {
	private int id;
	private String name;
	private Husband husband;
	@OneToOne(mappedBy="wife")
	public Husband getHusband() {
		return husband;
	}
	public void setHusband(Husband husband) {
		this.husband = husband;
	}
	@Id
	@GeneratedValue
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	
}

hibernate.cfg.xml:

package com.bjsxt.hibernate;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.OneToOne;

@Entity
public class Wife {
	private int id;
	private String name;
	private Husband husband;
	@OneToOne(mappedBy="wife")
	public Husband getHusband() {
		return husband;
	}
	public void setHusband(Husband husband) {
		this.husband = husband;
	}
	@Id
	@GeneratedValue
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	
}

junit语句:

package com.bjsxt.hibernate;

import java.util.Date;

import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.AnnotationConfiguration;
import org.hibernate.tool.hbm2ddl.SchemaExport;
import org.junit.AfterClass;
import org.junit.BeforeClass;
import org.junit.Test;

public class HibernateORMappingTest {
	private static SessionFactory sessionFactory;
	
	//@BeforeClass
	public static void beforeClass() {
			sessionFactory = new AnnotationConfiguration().configure().buildSessionFactory();
	}
	//@AfterClass
	public static void afterClass() {
		sessionFactory.close();
	}	
	
	@Test
	public void testSchemaExport() {
		new SchemaExport(new AnnotationConfiguration().configure()).create(false, true);
	}	
	public static void main(String[] args) {
		beforeClass();
	}
}

如果有双向关联 , mappedBy必设.

需要在wife里面设置, 这样husband作为主导.

xml里如何设置?

主导方: <many-to-one unique>   被主导方: <one-to-one property-ref>

1. student.java里设置:

private StuIdCard stuIdCard;
	public StuIdCard getStuIdCard() {
		return stuIdCard;
	}
	public void setStuIdCard(StuIdCard stuIdCard) {
		this.stuIdCard = stuIdCard;
	}

2. StuIdCard.java里设置:

        private Student student;
	public Student getStudent() {
		return student;
	}
	public void setStudent(Student student) {
		this.student = student;
	}    

3. Student.hbm.xml设置:

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping>
	<class name="com.bjsxt.hibernate.Student" dynamic-update="true">
		<id name="id">
			<generator class="native"></generator>
		</id>
		
		<property name="name"></property>
		<property name="age" />
		<property name="sex" />
		<property name="good" type="yes_no"></property>
		<one-to-one name="stuIdCard" property-ref="student"></one-to-one>
    </class>
	
</hibernate-mapping>

4. StuIdCard.hbm.xml设置:

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping>
	<class name="com.bjsxt.hibernate.StuIdCard">
		<id name="id">
			<generator class="native"></generator>
		</id>
		
		<property name="num"/>
		<many-to-one name="student" column="studentId" unique="true"></many-to-one>
    </class>
	
</hibernate-mapping>

junit测试文件仍然是:

package com.bjsxt.hibernate;

import java.util.Date;

import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.AnnotationConfiguration;
import org.hibernate.tool.hbm2ddl.SchemaExport;
import org.junit.AfterClass;
import org.junit.BeforeClass;
import org.junit.Test;

public class HibernateORMappingTest {
	private static SessionFactory sessionFactory;
	
	//@BeforeClass
	public static void beforeClass() {
			sessionFactory = new AnnotationConfiguration().configure().buildSessionFactory();
	}
	//@AfterClass
	public static void afterClass() {
		sessionFactory.close();
	}
	
	
	
	@Test
	public void testSchemaExport() {
		new SchemaExport(new AnnotationConfiguration().configure()).create(false, true);
	}
	
	public static void main(String[] args) {
		beforeClass();
	}
}