hibernate 用户以及其联系人列表的关系如何维护 在hibernate 用户以及其联系人列表的关系如何维护?用户和联系人列表中的对象都是Person对象。注意一个用户的联系人不止一个。我应该采用哪种方式实现,一对多?多对多?还是使用集合映射?望大家多多指点。谢谢。 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 多对多create table student(sid varchar ( 32 ) not null primary key , sname varchar ( 16 ), sage varchar ( 16 ),)create table course(cid varchar ( 32 ) not null primary key ,cname varchar ( 16 ))create table student_course_link(sid varchar ( 32 ) not null ,cid varchar ( 32 ) not null ,primary key (sid,cid))2.写VOStudentVOpackage com.test;import java.util.Set;public class Student{ private String sid; private String sname; private String sage; private Set course; public Student() { } //写上get setCourse vopackage com.test;import java.util.Set;public class Course{ private String cid; private String cname; private Set student; //写上get set写配置文件Student.hbm.xml<?xml version="1.0"?><!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD//EN" "http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd"><hibernate-mapping> <class name="com.test.Student" table="student" > <id name="sid" type="string" unsaved-value="null" > <column name="sid" sql-type="char(32)" not-null="true"/> <generator class="uuid.hex"/> </id> <property name="sname"> <column name="sname" sql-type="varchar(16)" not-null="true"/> </property> <property name="sage"> <column name="sage" sql-type="varchar(16)" not-null="true"/> </property> <set name="course" table="student_course_link" cascade="all" outer-join="false"> <key column="sid"/> <many-to-many class="com.test.Course" column="cid"/> </set> </class></hibernate-mapping>Course.hbm.xml<?xml version="1.0"?><!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD//EN" "http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd"><hibernate-mapping> <class name="com.test.Course" table="course" > <id name="cid" type="string" unsaved-value="null" > <column name="cid" sql-type="char(32)" not-null="true"/> <generator class="uuid.hex"/> </id> <property name="cname"> <column name="cname" sql-type="varchar(16)" not-null="true"/> </property> <set name="student" table="student_course_link" lazy="false" cascade="all"> <key column="cid"/> <many-to-many class="com.test.Student" column="sid"/> </set> </class></hibernate-mapping>希望对你有用,呵呵 hibernate的关系映射不经常用,我们的操作方式一般都是:将表和表之间的关系通过物理(sql来连接关系)。原因:如果表很多的话hibernate的关系映射太不好梳理、容易出错(个人建议)。 是这样的,用户和联系人列表中的对象都是Person对象。然后后对这个关系,我应该怎么处理呢? 求一个截取字符串的方法!!!分不多求帮忙 寻求精通jfreechart技术的砖家 给分,进来能说都点上的人就给分,砸锅卖铁的给分 java生成Exe问题 高手进!一个LFGs随机数生成器的编程问题(JAVA) 浮点型小数点后面怎么取两位??? 启动tomcat的时候出现的错误) resin 的问题,求助! 哪里能下载com.inet.tds.TdsDataSource?(分用完了,以后补。) java二维数组问题 weblogic JSP 预编译问题 为什么我用@Transactional后,getbean方法不能实现类型转换。
(sid varchar ( 32 ) not null primary key ,
sname varchar ( 16 ),
sage varchar ( 16 ),
)create table course
(cid varchar ( 32 ) not null primary key ,
cname varchar ( 16 )
)create table student_course_link
(sid varchar ( 32 ) not null ,
cid varchar ( 32 ) not null ,
primary key (sid,cid)
)2.写VO
StudentVO
package com.test;
import java.util.Set;
public class Student
{
private String sid;
private String sname;
private String sage; private Set course;
public Student()
{
}
//写上get set
Course vo
package com.test;import java.util.Set;public class Course
{
private String cid;
private String cname;
private Set student;
//写上get set写配置文件
Student.hbm.xml
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping
PUBLIC "-//Hibernate/Hibernate Mapping DTD//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd"><hibernate-mapping> <class name="com.test.Student" table="student" > <id name="sid" type="string" unsaved-value="null" >
<column name="sid" sql-type="char(32)" not-null="true"/>
<generator class="uuid.hex"/>
</id> <property name="sname">
<column name="sname" sql-type="varchar(16)" not-null="true"/>
</property> <property name="sage">
<column name="sage" sql-type="varchar(16)" not-null="true"/>
</property> <set name="course" table="student_course_link" cascade="all" outer-join="false">
<key column="sid"/>
<many-to-many class="com.test.Course" column="cid"/>
</set>
</class></hibernate-mapping>Course.hbm.xml
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping
PUBLIC "-//Hibernate/Hibernate Mapping DTD//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd"><hibernate-mapping> <class name="com.test.Course" table="course" > <id name="cid" type="string" unsaved-value="null" >
<column name="cid" sql-type="char(32)" not-null="true"/>
<generator class="uuid.hex"/>
</id> <property name="cname">
<column name="cname" sql-type="varchar(16)" not-null="true"/>
</property> <set name="student" table="student_course_link" lazy="false" cascade="all">
<key column="cid"/>
<many-to-many class="com.test.Student" column="sid"/>
</set>
</class></hibernate-mapping>希望对你有用,呵呵