两个类:
City和People两个类
package com.pk.po;
public class People {
private int id;
private String name;
private City city;
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;
}
public City getCity() {
return city;
}
public void setCity(City city) {
this.city = city;
}
}
package com.pk.po;
public class City {
private int id;
private String name;
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;
}
}
相关的映射文件
People.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 package="com.pk.po">
<class name="People" >
<id name="id">
<generator class="native"></generator>
</id>
<property name="name"></property>
<many-to-one name="city" cascade="all"></many-to-one>
</class>
<!--
此处用的是两个表相关联,只要保存一个表中的数据,也会影响相关联的表。
如果设置了city,则也会相应保存city到相应的表中,如果没有设置,则没有设置的属性就为空.
-->
</hibernate-mapping>
City.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 package="com.pk.po">
<class name="City">
<id name="id">
<generator class="native"></generator>
</id>
<property name="name"></property>
</class>
</hibernate-mapping>
配置文件
此处连接的是MySql数据库
Hibernate.cfg.xml
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/hibernate_hql</property>
<property name="hibernate.connection.username">root</property>
<property name="hibernate.connection.password">root</property>
<property name="show_sql">true</property>
<property name="dialect">org.hibernate.dialect.MySQLDialect</property>
<mapping resource="com/pk/po/City.hbm.xml"/>
<mapping resource="com/pk/po/People.hbm.xml"/>
</session-factory>
</hibernate-configuration>