多对多

相当于一个老师可以教多个学生，一个学生也可以有多个老师

数据表中都是再设计一个表寸相关的id

1.多对多单向

1annotation

Student.java

package com.bjsxt.hibernate;

import javax.persistence.Entity;

import javax.persistence.GeneratedValue;

import javax.persistence.Id;

import javax.persistence.ManyToOne;

import javax.persistence.Table;

@Entity

public class Student {

    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;

    }

}

teacher.java

package com.bjsxt.hibernate;

import java.util.HashSet;

import java.util.Set;

import javax.persistence.Entity;

import javax.persistence.GeneratedValue;

import javax.persistence.Id;

import javax.persistence.JoinColumn;

import javax.persistence.JoinTable;

import javax.persistence.ManyToMany;

import javax.persistence.OneToMany;

import javax.persistence.Table;

@Entity

public class Teacher {

    private int id;

    private String name;

    private Set<Student> students = new HashSet<Student>();

    @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;

    }

    @ManyToMany

    @JoinTable(name="t_s",

        joinColumns={@JoinColumn(name="teacher_id")},    //自己这个类的外键id

        inverseJoinColumns={@JoinColumn(name="student_id")}   //对方那张表的外键id

        )

    public Set<Student> getStudents() {

        return students;

    }

    public void setStudents(Set<Student> students) {

        this.students = students;

    }

}

hibernate.cfg.xml

<?xml version='1.0' encoding='utf-8'?>

<!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="connection.driver_class">com.mysql.jdbc.Driver</property>

        <property name="connection.url">jdbc:mysql://localhost/hibernate</property>

        <property name="connection.username">root</property>

        <property name="connection.password">bjsxt</property>

        <property name="dialect">org.hibernate.dialect.MySQLDialect</property>

       <!--

        <property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property>

        <property name="connection.url">jdbc:oracle:thin:@localhost::SXT</property>

        <property name="connection.username">scott</property>

        <property name="connection.password">tiger</property>

          <property name="dialect">org.hibernate.dialect.OracleDialect</property>

       -->

        <!-- JDBC connection pool (use the built-in) -->

        <property name="connection.pool_size"></property>

        <!-- Enable Hibernate's automatic session context management -->

        <property name="current_session_context_class">thread</property>

        <!-- Disable the second-level cache  -->

        <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</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 class="com.bjsxt.hibernate.Teacher"/>

        <mapping class="com.bjsxt.hibernate.Student"/>

        <!--

         <mapping resource="com/bjsxt/hibernate/Teacher.hbm.xml"/>

         <mapping resource="com/bjsxt/hibernate/Student.hbm.xml"/>

          -->

    </session-factory>

</hibernate-configuration>

测试代码

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();

    }

}

2.xml

student.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.Student">

        <id name="id">

            <generator class="native"></generator>

        </id>

        <property name="name"></property>

    </class>

</hibernate-mapping>

teacher.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.Student">

        <id name="id">

            <generator class="native"></generator>

        </id>

        <property name="name"></property>

    </class>

</hibernate-mapping>

hibernate.cfg.xml

<?xml version='1.0' encoding='utf-8'?>

<!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="connection.driver_class">com.mysql.jdbc.Driver</property>

        <property name="connection.url">jdbc:mysql://localhost/hibernate</property>

        <property name="connection.username">root</property>

        <property name="connection.password">bjsxt</property>

        <property name="dialect">org.hibernate.dialect.MySQLDialect</property>

       <!--

        <property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property>

        <property name="connection.url">jdbc:oracle:thin:@localhost::SXT</property>

        <property name="connection.username">scott</property>

        <property name="connection.password">tiger</property>

          <property name="dialect">org.hibernate.dialect.OracleDialect</property>

       -->

        <!-- JDBC connection pool (use the built-in) -->

        <property name="connection.pool_size"></property>

        <!-- Enable Hibernate's automatic session context management -->

        <property name="current_session_context_class">thread</property>

        <!-- Disable the second-level cache  -->

        <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</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 class="com.bjsxt.hibernate.Teacher"/>

        <mapping class="com.bjsxt.hibernate.Student"/>

         -->

         <mapping resource="com/bjsxt/hibernate/Teacher.hbm.xml"/>

         <mapping resource="com/bjsxt/hibernate/Student.hbm.xml"/>

    </session-factory>

</hibernate-configuration>

多对多双向关联

1.annotation

student.java

package com.bjsxt.hibernate;

import java.util.HashSet;

import java.util.Set;

import javax.persistence.Entity;

import javax.persistence.GeneratedValue;

import javax.persistence.Id;

import javax.persistence.ManyToMany;

@Entity

public class Student {

    private int id;

    private String name;

    private Set<Teacher> teachers = new HashSet<Teacher>();

    @ManyToMany(mappedBy="students")

    public Set<Teacher> getTeachers() {

        return teachers;

    }

    public void setTeachers(Set<Teacher> teachers) {

        this.teachers = teachers;

    }

    @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;

    }

}

Teacher.java

package com.bjsxt.hibernate;

import java.util.HashSet;

import java.util.Set;

import javax.persistence.Entity;

import javax.persistence.GeneratedValue;

import javax.persistence.Id;

import javax.persistence.JoinColumn;

import javax.persistence.JoinTable;

import javax.persistence.ManyToMany;

import javax.persistence.OneToMany;

import javax.persistence.Table;

@Entity

public class Teacher {

    private int id;

    private String name;

    private Set<Student> students = new HashSet<Student>();

    @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;

    }

    @ManyToMany

    @JoinTable(name="t_s",

        joinColumns={@JoinColumn(name="teacher_id")},

        inverseJoinColumns={@JoinColumn(name="student_id")}

        )

    public Set<Student> getStudents() {

        return students;

    }

    public void setStudents(Set<Student> students) {

        this.students = students;

    }

}

hibernate.cfg.xml

<?xml version='1.0' encoding='utf-8'?>

<!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="connection.driver_class">com.mysql.jdbc.Driver</property>

        <property name="connection.url">jdbc:mysql://localhost/hibernate</property>

        <property name="connection.username">root</property>

        <property name="connection.password">bjsxt</property>

        <property name="dialect">org.hibernate.dialect.MySQLDialect</property>

       <!--

        <property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property>

        <property name="connection.url">jdbc:oracle:thin:@localhost::SXT</property>

        <property name="connection.username">scott</property>

        <property name="connection.password">tiger</property>

          <property name="dialect">org.hibernate.dialect.OracleDialect</property>

       -->

        <!-- JDBC connection pool (use the built-in) -->

        <property name="connection.pool_size"></property>

        <!-- Enable Hibernate's automatic session context management -->

        <property name="current_session_context_class">thread</property>

        <!-- Disable the second-level cache  -->

        <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</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 class="com.bjsxt.hibernate.Teacher"/>

        <mapping class="com.bjsxt.hibernate.Student"/>
  <!--  
<mapping resource="com/bjsxt/hibernate/Teacher.hbm.xml"/> <mapping resource="com/bjsxt/hibernate/Student.hbm.xml"/>
 -->
        
</session-factory> </hibernate-configuration>

test.java

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();

    }

}

2。xml

Student.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.Student">

        <id name="id">

            <generator class="native"></generator>

        </id>

        <property name="name"></property>

        <set name="teachers" table="t_s">

            <key column="student_id"></key>

            <many-to-many class="com.bjsxt.hibernate.Teacher" column="teacher_id"/>

        </set>

    </class>

</hibernate-mapping>

Teacher.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.Teacher">

        <id name="id">

            <generator class="native"></generator>

        </id>

        <property name="name"></property>

        <set name="students" table="t_s">

            <key column="teacher_id"></key>

            <many-to-many class="com.bjsxt.hibernate.Student" column="student_id"/>

        </set>

    </class>

</hibernate-mapping>

hibernate.cfg.xml

<?xml version='1.0' encoding='utf-8'?>

<!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="connection.driver_class">com.mysql.jdbc.Driver</property>

        <property name="connection.url">jdbc:mysql://localhost/hibernate</property>

        <property name="connection.username">root</property>

        <property name="connection.password">bjsxt</property>

        <property name="dialect">org.hibernate.dialect.MySQLDialect</property>

       <!--

        <property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property>

        <property name="connection.url">jdbc:oracle:thin:@localhost::SXT</property>

        <property name="connection.username">scott</property>

        <property name="connection.password">tiger</property>

          <property name="dialect">org.hibernate.dialect.OracleDialect</property>

       -->

        <!-- JDBC connection pool (use the built-in) -->

        <property name="connection.pool_size"></property>

        <!-- Enable Hibernate's automatic session context management -->

        <property name="current_session_context_class">thread</property>

        <!-- Disable the second-level cache  -->

        <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</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 class="com.bjsxt.hibernate.Teacher"/>

        <mapping class="com.bjsxt.hibernate.Student"/>

         -->

        <mapping resource="com/bjsxt/hibernate/Teacher.hbm.xml"/>

         <mapping resource="com/bjsxt/hibernate/Student.hbm.xml"/>

    </session-factory>

</hibernate-configuration>

test一致

Hibernate学习笔记3.3（Hibernate组建映射2）的更多相关文章

  1. Hibernate学习笔记二：Hibernate缓存策略详解

    一:为什么使用Hibernate缓存: Hibernate是一个持久层框架,经常访问物理数据库. 为了降低应用程序访问物理数据库的频次,从而提高应用程序的性能. 缓存内的数据是对物理数据源的复制,应用 ...

  2. Hibernate学习笔记三：对象关系映射（一对一，一对多，多对一，多对多）

    如需转载,请说明出处:http://www.cnblogs.com/gudu1/p/6895610.html Hibernate通过关系映射来表示数据库中表与表之间的关系,关系映射可以通过两种方式:配 ...

  3. HIbernate学习笔记（六） 关系映射之多对多

    六.多对多 - 单向 Ø        一般的设计中,多对多关联映射,需要一个中间表 Ø        Hibernate会自动生成中间表 Ø        Hibernate使用many-to-ma ...

  4. HIbernate学习笔记（五） 关系映射之一对多与多对一

    三.       多对一 –单向 场景:用户和组:从用户角度来,多个用户属于一个组(多对一 关联) 使用hibernate开发的思路:先建立对象模型(领域模型),把实体抽取出来. 目前两个实体:用户和 ...

  5. Hibernate学习笔记（四）关系映射之一对一关联映射

    一. 一对一关联映射 ²        两个对象之间是一对一的关系,如Person-IdCard(人—身份证号) ²        有两种策略可以实现一对一的关联映射 Ø        主键关联:即让 ...

  6. Hibernate学习笔记(五) — 多对多关系映射

    多对多关系映射 多对多建立关系相当于在第三张表中插入一行数据 多对多解除关系相当于在第三张表中删除一行数据 多对多改动关系相当于在第三张表中先删除后添加 多对多谁维护效率都一样.看需求 在实际开发过程 ...

  7. Hibernate学习笔记--第一个Hibernate框架程序

    一般使用集成开发环境是,把所需的类库添加到项目属性的库路径中,开发工具在部署时会自动复制所需要的类包到WEB-INF\lib目录下 MyEclipse中: 创建项目,右击项目->myeclips ...

  8. Hibernate学习笔记（二）

    2016/4/22 23:19:44 Hibernate学习笔记(二) 1.1 Hibernate的持久化类状态 1.1.1 Hibernate的持久化类状态 持久化:就是一个实体类与数据库表建立了映 ...

  9. Hibernate学习笔记（一）

    2016/4/18 19:58:58 Hibernate学习笔记(一) 1.Hibernate框架的概述: 就是一个持久层的ORM框架. ORM:对象关系映射.将Java中实体对象与关系型数据库中表建 ...

  10. Hibernate 学习笔记一

    Hibernate 学习笔记一 今天学习了hibernate的一点入门知识,主要是配置domain对象和表的关系映射,hibernate的一些常用的配置,以及对应的一个向数据库插入数据的小例子.期间碰 ...

随机推荐

  1. 本地IP，掩码，网关，DNS设置

    using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.T ...

  2. insert into table 插入多条数据

    方法1: insert into `ttt` select '001','语文' union all select '002','数学' union all select '003','英语'; 方法 ...

  3. [UGUI]图文混排(七)：动态表情

    帧动画脚本: http://www.cnblogs.com/lyh916/p/9194823.html 这里的动态表情,我使用的是固定间隔去刷新Image上的Sprite来实现的,即帧动画.这里可以将 ...

  4. TIDB资料收集

    https://github.com/pingcap/docs-cn https://github.com/pingcap/docs-cn/blob/master/op-guide/binary-de ...

  5. Javascript 中 null和undefined的区别

    null表示"没有对象",即该处不应该有值.典型用法是: (1) 作为函数的参数,表示该函数的参数不是对象. (2) 作为对象原型链的终点. Object.getPrototype ...

  6. python中的partition、rpartition

    partition()从左向右寻找,以字符串中的某个元素为中心将左右分割共分割成三个元素并放入到元组中 partition()从右向左寻找,以字符串中的某个元素为中心将左右分割共分割成三个元素并放入到 ...

  7. Spring Maven项目集成Springboot

    Maven管理的Spring项目,准备集成Springboot做接口 1.Springboot对Spring有版本要求 我用的Springboot版本:1.4.5.RELEASE,对应Spring的版 ...

  8. checked选择器实现tab切换

    <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <meta http ...

  9. MySQL 5.7.20 ONLY_FULL_GROUP_BY

    < SQL_MODE 的配置方式 > 01,默认情况下 5.7.20 MySQL 开启该模式,我们可以用指 SQL 预计查看 => select @@global.sql_mode; ...

  10. ThinkCentre进入BIOS,设置intel virtualization technology

    VMware安装提示cpu虚拟化intel virtualization technology ThinkCentre重启长按F1 按enter,开启intel virtualization tech ...