Hibernate 多对多 删除操作

Hibernate 多对多 删除操作(many-to-many)

Hibernate多对多的例子不少，但仔细一看，大多数都是保存的，删除谈的少，但问题还不少，因此有必须简单测试一下，以下我们来个简单的多对多关系建立

老师Teacher 与 课程Course 是一个多对多的关系，Pojo与XMl配置如下。

Pojo

/**
 * Course Entity
 * see table: tbl_course
 */
package com.leo.domain;

import java.util.HashSet;
import java.util.Set;

/**
 * @author superleo
 * 
 */
public class Course {

 private String id;

 private String name;

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

 public String getId() {
  return id;
 }

 public void setId(String id) {
  this.id = id;
 }

 public String getName() {
  return name;
 }

 public void setName(String name) {
  this.name = name;
 }

 public Set<Teacher> getTeachers() {
  return teachers;
 }

 public void setTeachers(Set<Teacher> teachers) {
  this.teachers = teachers;
 }

}

/**
 * Teacher Entity
 * see table: tbl_teacher
 */
package com.leo.domain;

import java.util.HashSet;
import java.util.Set;

/**
 * @author superleo
 * 
 */
public class Teacher {

 private String id;

 private String name;

 private Set<Course> courses = new HashSet<Course>();

 public String getId() {
  return id;
 }

 public void setId(String id) {
  this.id = id;
 }

 public String getName() {
  return name;
 }

 public void setName(String name) {
  this.name = name;
 }

 public Set<Course> getCourses() {
  return courses;
 }

 public void setCourses(Set<Course> courses) {
  this.courses = courses;
 }

}

Hibernate配置文件：

<?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.leo.domain.Course" table="tbl_course"
  batch-size="100" dynamic-insert="true" dynamic-update="true">
  <id name="id" column="id">
   <generator class="uuid" />
  </id>
  <property name="name" column="name" type="string" />

  <set access="property" lazy="true" inverse="false"
   cascade="save-update" name="teachers" batch-size="10" fetch="select"
   table="tbl_teacher_course">
   <key column="fk_course_id" />
   <many-to-many class="com.leo.domain.Teacher"
    column="fk_teacher_id" />
  </set>

 </class>
</hibernate-mapping>

Xml代码：

<?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.leo.domain.Teacher" table="tbl_teacher"
  batch-size="100" dynamic-insert="true" dynamic-update="true">
  <id name="id" column="id">
   <generator class="uuid" />
  </id>
  <property name="name" column="name" type="string" />

  <set access="property" lazy="true" inverse="true"
   cascade="save-update" name="courses" batch-size="10" fetch="select"
   table="tbl_teacher_course">
   <key column="fk_teacher_id" />
   <many-to-many class="com.leo.domain.Course"
    column="fk_course_id" />
  </set>

 </class>
</hibernate-mapping>