Hibernate 实现 多对一 例子

public class Dept {    private  Integer deptNo;    private  String deptName;    public Integer getDeptNo() {        return deptNo;    }    public void setDeptNo(Integer deptNo) {        this.deptNo = deptNo;    }    public String getDeptName() {        return deptName;    }    public void setDeptName(String deptName) {        this.deptName = deptName;    }}

<?xml version="1.0"?><!DOCTYPE hibernate-mapping PUBLIC        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"><hibernate-mapping package="cn.hello.hql2.one" schema="happyy2165">    <class name="Dept" table="Dept" dynamic-update="true">        <id name="deptNo" column="deptNo">            <generator class="native"/>        </id>        <property name="deptName" column="deptName"></property>    </class></hibernate-mapping>

package cn.hello.hql2.one;import java.util.Date;public class Emp {    private Integer empno;    private String ename;    private Dept dept=new Dept();    public Dept getDept() {        return dept;    }    public void setDept(Dept dept) {        this.dept = dept;    }    public Integer getEmpno() {        return empno;    }    public void setEmpno(Integer empno) {        this.empno = empno;    }    public String getEname() {        return ename;    }    public void setEname(String ename) {        this.ename = ename;    }}

<?xml version='1.0' encoding='utf-8'?><!DOCTYPE hibernate-mapping PUBLIC        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"><hibernate-mapping package="cn.hello.hql2.one"><class name="Emp" table="Emp" schema="happyy2165">    <id name="empno" column="empno">        <generator class="native"></generator>    </id>    <property name="ename" column="ename"/>    <many-to-one name="dept" column="deptno" class="cn.hello.hql2.one.Dept"></many-to-one></class></hibernate-mapping>

public class text20171006_2 {    Configuration cfg;    Session session;    Transaction tx;    SessionFactory factory;    @Before    public  void before(){        cfg=new Configuration().configure();        factory = cfg.buildSessionFactory();        session = HibmentUtil.getSession();        tx = session.beginTransaction();    }    @Test    // 多对一    public  void  aVoid(){        cn.hello.hql2.one.Emp emp = session.get(cn.hello.hql2.one.Emp.class, 1);        System.out.println(emp.getDept().getDeptName());    }}

<?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>        <!-- Database connection settings -->        <property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property>        <property name="connection.url">jdbc:oracle:thin:@localhost:1521:orcl</property>        <property name="connection.username">happyy2165</property>        <property name="connection.password">a123456a</property>        <!-- JDBC connection pool (use the built-in) -->        <property name="connection.pool_size">1</property>        <!-- SQL dialect -->        <property name="dialect">org.hibernate.dialect.Oracle10gDialect</property>        <!-- 使用getCurrentSession 进行配置-->        <!-- Enable Hibernate's automatic session context management -->        <property name="current_session_context_class">thread</property>        <!-- Echo all executed SQL to stdout -->        <property name="show_sql">true</property>        <property name="format_sql">true</property>        <!-- Drop and re-create the database schema on startup -->        <property name="hbm2ddl.auto">update</property>        <mapping resource="cn/hello/entity/Dog.hbm.xml"/>        <mapping resource="cn/hello/hql/Dept.hbm.xml"/>        <mapping resource="cn/hello/entity/Emp.hbm.xml"/>        <mapping resource="cn/hello/hql2/one/Emp.hbm.xml"/>        <mapping resource="cn/hello/hql2/one/Dept.hbm.xml"/>        <mapping resource="cn/hello/hql2/two/Emp.hbm.xml"/>        <mapping resource="cn/hello/hql2/two/Dept.hbm.xml"/>        <mapping resource="cn/hello/hql2/three/Employee.hbm.xml"/>        <mapping resource="cn/hello/hql2/three/Project.hbm.xml"/>    </session-factory></hibernate-configuration>