hibernate的一对一映射-主键映射-单向-mysql数据库

hibernate的一对一映射-主键映射-单向-mysql数据库

import java.io.Serializable;

import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.Id;
import javax.persistence.OneToOne;
import javax.persistence.PrimaryKeyJoinColumn;
import javax.persistence.Table;
/**
* 1对1 单向
* 主键关联
* @author WuJieJecket
* alt +上/下 交换两行代码
* ctrl+alt +上/下复制一行代码
*/
@Entity(name="DNFCLASS")
@Table(name="DNFCLASS")
@SuppressWarnings("serial")
public class Dnfclass implements Serializable {
private String dclassname;
private Dnfstudent dfs;
/**
* @return the dclassname
*/
@Id
@Column(name="DCLASSNAME")
public String getDclassname() {
return dclassname;
}
/**
* @param dclassname the dclassname to set
*/
public void setDclassname(String dclassname) {
this.dclassname = dclassname;
}
/**
* @return the dfs
*/
@OneToOne(cascade=CascadeType.ALL,fetch=FetchType.LAZY)
@PrimaryKeyJoinColumn//主键依赖，就没有外键这么一说了
public Dnfstudent getDfs() {
return dfs;
}
/**
* @param dfs the dfs to set
*/
public void setDfs(Dnfstudent dfs) {
this.dfs = dfs;
}

}

import java.io.Serializable;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity(name="DNFSTUDENT")
@Table(name="DNFSTUDENT")
@SuppressWarnings("serial")
public class Dnfstudent implements Serializable {
private String dstudentname;

/**
* @return the dstudentname
*/
@Id
@Column(name="DSTUDENTNAME")
public String getDstudentname() {
return dstudentname;
}

/**
* @param dstudentname the dstudentname to set
*/
public void setDstudentname(String dstudentname) {
this.dstudentname = dstudentname;
}

}

配置文件

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-configuration PUBLIC

        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"

        "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">

<hibernate-configuration>

<session-factory>
<!-- 数据库驱动 -->
<property name="connection.driver_class">
com.mysql.jdbc.Driver
</property>
<!-- 链接数据库的url -->
<property name="connection.url">
jdbc:mysql://localhost:3306/test
</property>
<!-- 数据库链接用户名 -->
<property name="connection.username">用户名</property>
<!-- 数据库链接密码 -->
<property name="connection.password">密码</property>
<!-- sql方言 -->
<property name="dialect">
org.hibernate.dialect.MySQLDialect
</property>
<!-- 是否打印sql语句 -->
<property name="show_sql">true</property>
<property name="format_sql">true</property>
<property name="hbm2ddl.auto">update</property>
<mapping class="hibernate.dnfonetoone.Dnfclass" />
<mapping class="hibernate.dnfonetoone.Dnfstudent" />

</session-factory>

</hibernate-configuration>

测试方法

/*
* 1对1 单向 主键关联
*/
@Test
public void testnfOnetoone(){

HIbernateUtil hbu=new HIbernateUtil();
Session s=hbu.getSession();
s.beginTransaction();

Dnfstudent dst=new Dnfstudent();
dst.setDstudentname("小明"+hbu.returnid());

Dnfclass dc=new Dnfclass();
dc.setDclassname("语文"+hbu.returnid());
dc.setDfs(dst);

s.save(dc);

s.getTransaction().commit();
s.close();
}