这里的关系指的是对象与对象之间的关系
注解方式单向关联一对一：
//这个类描述的husband是一个对应一个wife的
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")//指定生成的表该外键的字段名，不指定会自动生成系统默认的字段名wife_id
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;
}
}
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
@Entity
public class Wife {
private int id;
private String name;
@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;
}
}
测试类：
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);//配置了log4j可以看到生成语句
}
public static void main(String[] args) {
beforeClass();
}
}
配置文件
<hibernate-configuration>
……
<mapping class="com.bjsxt.hibernate.Husband"/>
<mapping class="com.bjsxt.hibernate.Wife"/>
</session-factory>
</hibernate-configuration>
</session-factory>
</hibernate-configuration>
xml方式：
StuIdCard.hbm.xml
<?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><!-- unique唯一的，manytoone是多对一，加上unique就是一对一了，表示StuIdCard单向一对一对应 student，name设为本类的student属性（StuIdCard类中要定义private Student student属性），column表示用哪个字段作为外键关联字段 -->
</class>
</hibernate-mapping>
