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Hibernate 一对多单向关联Demo
以Classes[班级]和Student[学生]为例的Demo
Classes .javapublic class Classes implements Serializable { private long Cid; private String Cname; private String Cdesc; private Set<Student> students; //get和set }
Student .javapublic class Student implements Serializable { private long Sid; private String Sname; private String Sdesc;//get和set}
映射文件：
1 <?xml version="1.0" encoding="UTF-8"?> 2 <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" 3 "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> 4 <hibernate-mapping> 5 <class name="cn.test.test.Classes" table="classes"> 6 <id name="Cid" type="java.lang.Long" length="5"> 7 <column name="Cid"></column> 8 <generator class="increment"></generator> 9 </id>10 <property name="Cname" type="java.lang.String" length="20"></property>11 <property name="Cdesc" type="java.lang.String" length="50"></property>12 13 <!-- 14 set元素和类中的set集合对应15 * 从外键的角度建立classes与student之间的关系16 * 从类与类的角度建立classes与student之间的关系17 cascade级联18 inverse是用来维护关系的19 * 要么是一对多的关系20 * 要么多对多的关系21 * 谁来维护关系22 inverse所在的映射文件对应的持久化对象维护关系23 默认值是false 表明维护关系24 true 表明不维护关系25 -->26 <set name="students" cascade="all">27 <!-- 28 key是用来描述外键29 column就代表外键的名字30 -->31 <key>32 <column name="Cid"></column>33 </key>34 <!-- 35 classes和哪个对象进行关联36 -->37 <one-to-many class="cn.test.test.Student"/>38 </set>39 40 </class>41 </hibernate-mapping>
1 <?xml version="1.0" encoding="UTF-8"?> 2 <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" 3 "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> 4 <hibernate-mapping> 5 <class name="cn.test.test.Student" table="student"> 6 <id name="Sid" type="java.lang.Long" length="5"> 7 <column name="Sid"></column> 8 <generator class="increment"></generator> 9 </id>10 <property name="Sname" type="java.lang.String" length="20"></property>11 <property name="Sdesc" type="java.lang.String" length="50"></property>12 </class>13 </hibernate-mapping>
1 package cn.test.test; 2 3 import java.util.HashSet; 4 import java.util.List; 5 import java.util.Set; 6 7 import javax.crypto.interfaces.PBEKey; 8 9 import org.hibernate.Session; 10 import org.hibernate.SessionFactory; 11 import org.hibernate.Transaction; 12 import org.hibernate.cfg.Configuration; 13 import org.junit.Test; 14 15 public class DoTest { 16 /** 17 * 1、保存班级 18 * 2、保存学生 19 * 3、保存班级的时候同时保存学生 20 * 4、保存班级的时候同时保存学生，并且建立班级和学生之间的关系 21 * 5、已经存在一个班级，新建一个学生，并且建立该学生和该班级之间的关系 22 * 6、已经存在一个学生，新建一个班级，并且建立该学生和该班级之间的关系 23 * 7、已经存在一个学生，已经存在一个班级，解除该学生和原来班级之间的关系，建立该学生和新班级之间的关系 24 * 8、已经存在一个学生，解除该学生和该学生所在班级之间的关系 25 * 9、解除该班级和所有的学生之间的关系，再重新建立该班级和一些新的学员之间的关系 26 * 10、解除该班级和所有的学生之间的关系 27 * 11、删除班级 28 * * 29 * * 解除该班级和所有的学生之间的关系 30 * * 删除该班级 31 * * 32 * 删除班级的同时删除学生 33 * 12、删除学生 34 * 同删除班级 35 */ 36 37 private static SessionFactory sessionFactory; 38 static{ 39 Configuration configuration=new Configuration(); 40 configuration.configure(); 41 sessionFactory=configuration.buildSessionFactory(); 42 } 43 44 //1、保存班级 45 @Test 46 public void testSaveClasses(){ 47 Session session=sessionFactory.openSession(); 48 Transaction transaction= session.beginTransaction(); 49 Classes classes=new Classes(); 50 classes.setCname("Tom"); 51 classes.setCdesc("1234567890-"); 52 session.save(classes); 53 transaction.commit(); 54 session.close(); 55 } 56 //2、保存学生 57 @Test 58 public void testSaveStudents(){ 59 Session session=sessionFactory.openSession(); 60 Transaction transaction= session.beginTransaction(); 61 Student student=new Student(); 62 student.setSname("屌丝班"); 63 student.setSdesc("都是纯逗比纯屌丝"); 64 session.save(student); 65 transaction.commit(); 66 session.close(); 67 } 68 //3、保存班级的时候同时保存学生 69 /* 70 * Hibernate: select max(Sid) from student 71 Hibernate: select max(Cid) from classes 72 Hibernate: insert into student (Sname, Sdesc, Sid) values (?, ?, ?) 73 Hibernate: insert into classes (Cname, Cdesc, Cid) values (?, ?, ?) 74 */ 75 @Test 76 public void testSaveClasses_Students(){ 77 Session session=sessionFactory.openSession(); 78 Transaction transaction= session.beginTransaction(); 79 80 Student student=new Student(); 81 student.setSname("屌丝班"); 82 student.setSdesc("都是纯逗比纯屌丝"); 83 session.save(student); 84 85 Classes classes=new Classes(); 86 classes.setCname("Tom"); 87 classes.setCdesc("1234567890-"); 88 session.save(classes); 89 90 transaction.commit(); 91 session.close(); 92 } 93 94 //4、保存班级的时候同时保存学生，并且建立班级和学生之间的关系 95 /*classes.hbm.xml中设置;<set name="students" cascade="save-update"> 96 * Hibernate: select max(Cid) from classes 97 Hibernate: select max(Sid) from student 98 Hibernate: insert into classes (Cname, Cdesc, Cid) values (?, ?, ?) 99 Hibernate: insert into student (Sname, Sdesc, Sid) values (?, ?, ?)100 Hibernate: update student set Cid=? where Sid=?101 102 保存班级的时候同时保存学生，并且建立班级和学生之间的关系103 * 在classes.hbm.xml文件中104 * <set name="students" cascade="save-update">105 * inverse的值为默认或者false,才能让classes维护student的关系106 设置<set name="students" cascade="save-update" inverse="true">107 Hibernate: select max(Cid) from classes108 Hibernate: select max(Sid) from student109 Hibernate: insert into classes (Cname, Cdesc, Cid) values (?, ?, ?)110 Hibernate: insert into student (Sname, Sdesc, Sid) values (?, ?, ?)111 不建立关联112 */113 @Test114 public void testSaveClasses_R_Students(){115 Session session=sessionFactory.openSession();116 Transaction transaction= session.beginTransaction();117 118 Student student=new Student();119 student.setSname("Tom");120 student.setSdesc("1234567890-"); 121 122 //session.save(student);必须删除掉123 124 Set<Student> students=new HashSet<Student>();125 students.add(student);126 127 Classes classes=new Classes();128 classes.setCname("屌丝班");129 classes.setCdesc("都是纯逗比纯屌丝");130 131 classes.setStudents(students);132 133 session.save(classes);134 135 transaction.commit();136 session.close();137 }138 139 140 //5、已经存在一个班级，新建一个学生，并且建立该学生和该班级之间的关系141 /**142 * Hibernate: select classes0_.Cid as Cid1_0_, classes0_.Cname as Cname1_0_, classes0_.Cdesc as Cdesc1_0_ from classes classes0_ where classes0_.Cid=?143 Hibernate: select students0_.Cid as Cid1_1_, students0_.Sid as Sid1_, students0_.Sid as Sid0_0_, students0_.Sname as Sname0_0_, students0_.Sdesc as Sdesc0_0_ from student students0_ where students0_.Cid=?144 Hibernate: select max(Sid) from student145 Hibernate: insert into student (Sname, Sdesc, Sid) values (?, ?, ?)146 Hibernate: update student set Cid=? where Sid=?147 */148 @Test149 public void testSaveClassesAndStudents_R(){150 Session session=sessionFactory.openSession();151 Transaction transaction=session.beginTransaction();152 Classes classes=(Classes) session.get(Classes.class, 1L);153 Student student=new Student();154 student.setSname("Lucy");155 student.setSdesc("qwertyuiop");156 Set<Student> set=new HashSet<Student>();157 //建立关系158 classes.getStudents().add(student);159 160 //classes.setStudents(set); 把班级中的学生重新更新了161 162 transaction.commit();163 session.close();164 }165 //6、已经存在一个学生，新建一个班级，并且建立该学生和该班级之间的关系166 /*167 * Hibernate: select student0_.Sid as Sid0_0_, student0_.Sname as Sname0_0_, student0_.Sdesc as Sdesc0_0_ from student student0_ where student0_.Sid=?168 Hibernate: select max(Cid) from classes169 Hibernate: insert into classes (Cname, Cdesc, Cid) values (?, ?, ?)170 Hibernate: update student set Cid=? where Sid=?171 */172 @Test173 public void testSaveStudentAndClasses_R(){174 Session session =sessionFactory.openSession();175 Transaction transaction= session.beginTransaction();176 177 Student student=(Student) session.get(Student.class, 2L);178 179 Classes classes=new Classes();180 classes.setCname("文艺青年班");181 classes.setCdesc("感觉都是文艺青年棒棒哒");182 183 Set<Student> set=new HashSet<Student>();184 set.add(student);185 classes.setStudents(set);186 187 session.save(classes);188 189 transaction.commit();190 session.close();191 }192 193 //7、已经存在一个学生，已经存在一个班级，解除该学生和原来班级之间的关系，建立该学生和新班级之间的关系194 /*195 * Hibernate: select student0_.Sid as Sid0_0_, student0_.Sname as Sname0_0_, student0_.Sdesc as Sdesc0_0_ from student student0_ where student0_.Sid=?196 Hibernate: select classes0_.Cid as Cid1_0_, classes0_.Cname as Cname1_0_, classes0_.Cdesc as Cdesc1_0_ from classes classes0_ where classes0_.Cid=?197 Hibernate: select students0_.Cid as Cid1_1_, students0_.Sid as Sid1_, students0_.Sid as Sid0_0_, students0_.Sname as Sname0_0_, students0_.Sdesc as Sdesc0_0_ from student students0_ where students0_.Cid=?198 Hibernate: update student set Cid=? where Sid=?//建立关系199 * 200 */201 @Test202 public void testSaveRemove_Student_Classes(){203 Session session=sessionFactory.openSession();204 Transaction transaction=session.beginTransaction();205 Student student=(Student) session.get(Student.class, 2L);206 207 Classes classes=(Classes) session.get(Classes.class, 1L);208 classes.getStudents().add(student);//建立关系，没有必要删除与原来班级的关系，建立关系之后，自动解除与原来班级的关系209 transaction.commit();210 session.close();211 }212 //8、已经存在一个学生，解除该学生和该学生所在班级之间的关系213 /*214 * Hibernate: select student0_.Sid as Sid0_0_, student0_.Sname as Sname0_0_, student0_.Sdesc as Sdesc0_0_ from student student0_ where student0_.Sid=?215 Hibernate: select classes0_.Cid as Cid1_0_, classes0_.Cname as Cname1_0_, classes0_.Cdesc as Cdesc1_0_ from classes classes0_ where classes0_.Cid=?216 Hibernate: select students0_.Cid as Cid1_1_, students0_.Sid as Sid1_, students0_.Sid as Sid0_0_, students0_.Sname as Sname0_0_, students0_.Sdesc as Sdesc0_0_ from student students0_ where students0_.Cid=?217 Hibernate: update student set Cid=null where Cid=? and Sid=?218 * 219 */220 @Test221 public void testRemoveStudent(){222 Session session=sessionFactory.openSession();223 Transaction transaction =session.beginTransaction();224 225 Student student=(Student) session.get(Student.class, 1L);226 Classes classes=(Classes)session.get(Classes.class, 1L);227 classes.getStudents().remove(student);228 transaction.commit();229 session.close();230 }231 232 //9、解除该班级和所有的学生之间的关系，再重新建立该班级和一些新的学员之间的关系233 /*234 * Hibernate: select classes0_.Cid as Cid1_0_, classes0_.Cname as Cname1_0_, classes0_.Cdesc as Cdesc1_0_ from classes classes0_ where classes0_.Cid=?235 Hibernate: select student0_.Sid as Sid0_, student0_.Sname as Sname0_, student0_.Sdesc as Sdesc0_ from student student0_ where student0_.Sid in (3 , 4 , 5)236 Hibernate: update student set Cid=null where Cid=?237 Hibernate: update student set Cid=? where Sid=?238 Hibernate: update student set Cid=? where Sid=?239 Hibernate: update student set Cid=? where Sid=?240 * 241 */242 @Test243 public void testRemoveAllAndAddSome(){244 Session session =sessionFactory.openSession();245 Transaction transaction= session.beginTransaction();246 247 Classes classes=(Classes) session.get(Classes.class, 1L);248 List<Student> students= session.createQuery("FROM Student WHERE Sid IN(3,4,5) ").list();249 250 Set<Student> sets=new HashSet<Student>(students); 251 classes.setStudents(sets);252 253 transaction.commit();254 session.close();255 }256 257 //10、解除该班级和所有的学生之间的关系258 /*259 * Hibernate: select classes0_.Cid as Cid1_0_, classes0_.Cname as Cname1_0_, classes0_.Cdesc as Cdesc1_0_ from classes classes0_ where classes0_.Cid=?260 Hibernate: update student set Cid=null where Cid=?261 */262 @Test263 public void testRemoveAll(){264 Session session=sessionFactory.openSession();265 Transaction transaction =session.beginTransaction();266 267 Classes classes=(Classes) session.get(Classes.class, 1L);268 classes.setStudents(null);269 270 transaction.commit();271 session.close();272 }273 /*274 * 11、删除班级275 * *276 * * 解除该班级和所有的学生之间的关系277 * * 删除该班级278 * * 279 * 删除班级的同时删除学生280 * 12、删除学生281 * 同删除班级282 * 283 */284 //11、删除学生,同删除班级285 /*286 * Hibernate: select classes0_.Cid as Cid1_0_, classes0_.Cname as Cname1_0_, classes0_.Cdesc as Cdesc1_0_ from classes classes0_ where classes0_.Cid=?287 Hibernate: select students0_.Cid as Cid1_1_, students0_.Sid as Sid1_, students0_.Sid as Sid0_0_, students0_.Sname as Sname0_0_, students0_.Sdesc as Sdesc0_0_ from student students0_ where students0_.Cid=?288 Hibernate: update student set Cid=null where Cid=?289 Hibernate: delete from student where Sid=?290 Hibernate: delete from student where Sid=?291 Hibernate: delete from student where Sid=?292 Hibernate: delete from classes where Cid=?293 */294 @Test295 public void testDeleteClasses(){296 Session session =sessionFactory.openSession();297 Transaction transaction=session.beginTransaction();298 299 Classes classes=(Classes) session.get(Classes.class, 1L);300 session.delete(classes);301 302 transaction.commit();303 session.close();304 } 305 }
Hibernate 一对多单向关联Demo
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