Hibernate Mapping笔记
来源：互联网 发布：复杂网络可视化 编辑：程序博客网 时间：2024/04/30 00:05
用Hibernate已经有一段时间了，觉得关键还是设计对象时与数据库的映射策略最为关键。故而将已前写的笔记再翻出来看了看，今天将其记录在这里（好久都没来这写东西了，近来项目超得紧）
Hibernate Mapping笔记
一、List属性映射
数据库中有两个表，user和school表示一个用户所对应的学历信息，表结构下所示
用户表：
CREATE TABLE `user` (
`uid` int(11) NOT NULL AUTO_INCREMENT,
`uname` varchar(32) DEFAULT NULL,
`upassword` varchar(32) DEFAULT NULL,
`usex` int(11) DEFAULT NULL,
`uage` datetime DEFAULT NULL,
PRIMARY KEY (`uid`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
学历表：
CREATE TABLE `school` (
`uid` int(11) NOT NULL,
`sname` varchar(255) DEFAULT NULL,
`list_order` int(11) NOT NULL,
PRIMARY KEY (`uid`,`list_order`),
KEY `FKC9E15B74B3DCEEC2` (`uid`),
CONSTRAINT `FKC9E15B74B3DCEEC2` FOREIGN KEY (`uid`) REFERENCES `user` (`uid`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
其中学历表school在对象模型中用List来表示，所以在Hibernate对象模型映射中为user设计user.java PO类，代码如下：
public class User implements java.io.Serializable {
private Integer uid;
private String uname;
private String upassword;
private Integer usex;
private Date uage;
private List school = new ArrayList();
public User() {
}
...........
}
User.hbm.xml映射文件如下：
<?xml version="1.0" encoding="utf-8"?>
<!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.gxd.list.po.User" table="user">
<id name="uid" type="integer">
<column name="uid" />
<generator class="native" />
</id>
<property name="uname" type="string">
<column name="uname" length="32" />
</property>
<property name="upassword" type="string">
<column name="upassword" length="32" />
</property>
<property name="usex" type="integer">
<column name="usex" />
</property>
<property name="uage" type="timestamp">
<column name="uage" length="0" />
</property>
<!-- 映射集合属性,指定存放集合属性的表名 -->
<list name="school" table="school">
<!-- 集合属性的持久化类的关联外键 -->
<key column="uid" not-null="true"></key>
<!-- 集合属性的次序列 -->
<index column="list_order"></index>
<!-- 集合属性的元素 -->
<element type="string" column="sname"></element>
</list>
</class>
</hibernate-mapping>
测试类代码如下：
public static void main(String[] args) {
Operator op = new Operator() ;
User user = new User();
user.setUname("east");
user.setUpassword("123");
user.setUsex(1);
user.setUage(new Date());
List<String> l = new ArrayList<String>();
l.add("沙田完小");
l.add("沙田中学");
l.add("武汉大学");
user.setSchool(l);
op.addUser(user);
user = new User();
user.setUname("lili");
user.setUpassword("456");
user.setUsex(2);
user.setUage(new Date());
l = new ArrayList<String>();
l.add("贝溪小学");
l.add("桂东二中");
l.add("湖南大学");
l.add("哈佛大学");
l.add("剑桥大学MBA");
user.setSchool(l);
op.addUser(user);
}
public void addUser(User user) {
session.save(user);
session.beginTransaction().commit();
}
控制台执行结果：
Hibernate: insert into user (uname, upassword, usex, uage) values (?, ?, ?, ?)
Hibernate: insert into school (uid, list_order, sname) values (?, ?, ?)
Hibernate: insert into school (uid, list_order, sname) values (?, ?, ?)
Hibernate: insert into school (uid, list_order, sname) values (?, ?, ?)
Hibernate: insert into user (uname, upassword, usex, uage) values (?, ?, ?, ?)
Hibernate: insert into school (uid, list_order, sname) values (?, ?, ?)
Hibernate: insert into school (uid, list_order, sname) values (?, ?, ?)
Hibernate: insert into school (uid, list_order, sname) values (?, ?, ?)
Hibernate: insert into school (uid, list_order, sname) values (?, ?, ?)
Hibernate: insert into school (uid, list_order, sname) values (?, ?, ?)
表结果：
主键情况：
发现uid与list_order成了联合主键
二、Set集合属性映射
Set集合属性映射与List集合属性映射特别相似，但因为 Set是无序的、不可重复的集合，因此Set元素无需index元素来指定集合元素的次序。
Student表：
CREATE TABLE `student` (
`stuID` int(11) NOT NULL AUTO_INCREMENT,
`stuname` varchar(32) DEFAULT NULL,
PRIMARY KEY (`stuID`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
Student_subject表：
CREATE TABLE `student_subject` (
`stuID` int(11) NOT NULL,
`subject` varchar(255) NOT NULL,
PRIMARY KEY (`stuID`,`subject`),
KEY `FKBB
CONSTRAINT `FKBB
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
PO：
public class Student implements Serializable {
private Integer stuID ;
private String stuName ;
private Set<String> subject = new HashSet<String>();
public Student() {
}
...........
}
Student.hbm.xml
<hibernate-mapping>
<class name="com.gxd.set.po.Student" table="student">
<id name="stuID" type="integer">
<column name="stuID" />
<generator class="native" />
</id>
<property name="stuName" type="string">
<column name="stuname" length="32" />
</property>
<!-- 映射SET集合属性,指定学生科目对应的数据表 -->
<set name="subject" table="student_subject">
<!-- 集合属性的外键列 -->
<key column="stuID" not-null="true"></key>
<!-- 集合中的元素 -->
<element type="string" column="subject" not-null="true"></element>
</set>
</class>
</hibernate-mapping>
TEST：
public static void main(String[] args) {
Operator op = new Operator() ;
Student stu = new Student() ;
stu.setStuName("张三");
Set<String> subject = new HashSet<String>();
subject.add("语文");
subject.add("数学");
stu.setSubject(subject);
op.addStudent(stu);
stu = new Student() ;
stu.setStuName("李四");
subject = new HashSet<String>();
subject.add("语文");
subject.add("数学");
subject.add("外语");
stu.setSubject(subject);
op.addStudent(stu);
}
public void addStudent(Student stu) {
session.save(stu);
session.beginTransaction().commit();
}
控制台执行结果：
Hibernate: insert into student (stuname) values (?)
Hibernate: insert into student_subject (stuID, subject) values (?, ?)
Hibernate: insert into student_subject (stuID, subject) values (?, ?)
Hibernate: insert into student (stuname) values (?)
Hibernate: insert into student_subject (stuID, subject) values (?, ?)
Hibernate: insert into student_subject (stuID, subject) values (?, ?)
Hibernate: insert into student_subject (stuID, subject) values (?, ?)
表结果：
我们发现stuID&subject成了联合主键，这是因为我们将element元素包括了not-null=”true”属性，如果不包含此属性，则student_subject表没有主键
三、Map集合属性映射
PO：
public class Config implements Serializable {
private int configID ;
private String configDescribe ;
private Map cfg = new HashMap(0) ;
public Map getCfg() {
return cfg;
}
public void setCfg(Map cfg) {
this.cfg = cfg;
}
public String getConfigDescribe() {
return configDescribe;
}
public void setConfigDescribe(String configDescribe) {
this.configDescribe = configDescribe;
}
public int getConfigID() {
return configID;
}
public void setConfigID(int configID) {
this.configID = configID;
}
}
Config.hbm.xml
<?xml version="1.0" encoding="utf-8"?>
<!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.gxd.map.po.Config" table="config">
<id name="configID" type="integer">
<column name="CFGID" />
<generator class="native" />
</id>
<property name="configDescribe" type="string">
<column name="CFGDESCRIBE" length="32" />
</property>
<!-- 映射MAP集合属性 -->
<map name="cfg" table="cfg">
<!-- 映射外键列 -->
<key column="configID" not-null="true"/>
<!-- 映射Map KEY -->
<map-key type="string" column="cfgName"/>
<!-- 映射Map VALUE -->
<element type="string" column="cfgValue"/>
</map>
</class>
</hibernate-mapping>
测试：
public static void main(String[] args) {
Operator op = new Operator() ;
Config config = new Config() ;
config.setConfigDescribe("网站名称");
Map cfg = new HashMap() ;
cfg.put("siteName", "神彩飞扬技术在线");
config.setCfg(cfg);
op.addConfig(config);
config = new Config() ;
config.setConfigDescribe("网站域名");
cfg = new HashMap() ;
cfg.put("siteDomain", "www.guoxiaodong.net");
config.setCfg(cfg);
op.addConfig(config);
}
public void addConfig(Config config) {
session.save(config);
session.beginTransaction().commit();
}
测试二（这种方式是一样的）
public static void main(String[] args) {
Operator op = new Operator() ;
Config config = new Config() ;
config.setConfigDescribe("网站名称");
config.getCfg().put("siteName", "神彩飞扬技术在线");
op.addConfig(config);
config = new Config();
config.setConfigDescribe("网站域名");
config.getCfg().put("siteDomain", "www.guoxiaodong.net");
op.addConfig(config);
}
public void addConfig(Config config) {
session.save(config);
session.beginTransaction().commit();
}
config表：
CREATE TABLE `config` (
`CFGID` int(11) NOT NULL AUTO_INCREMENT,
`CFGDESCRIBE` varchar(32) DEFAULT NULL,
PRIMARY KEY (`CFGID`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
Cfg表：
CREATE TABLE `cfg` (
`configID` int(11) NOT NULL,
`cfgValue` varchar(255) DEFAULT NULL,
`cfgName` varchar(255) NOT NULL,
PRIMARY KEY (`configID`,`cfgName`),
KEY `FK1806453B90BB4` (`configID`),
CONSTRAINT `FK1806453B90BB4` FOREIGN KEY (`configID`) REFERENCES `config` (`CFGID`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
两个表均为Hibernate生成的表
控制台执行结果：
四、 映射引用属性
引用属性的意思是：持久化类的属性既不是基本数据类型，也不是Stirng字符串，而是某个引用变量，该引用属性的类型可以是自定义类。
PO：
public class Person implements Serializable{
private int id ;
private int age ;
private Name name ; //引用属性name
..........
}
public class Name {
private String firstName ;
private String lastName ;
.......
}
Person.hbm.xml：
<hibernate-mapping>
<class name="com.gxd.component.po.Person" table="person">
<id name="id" type="integer">
<column name="personID" />
<generator class="native" />
</id>
<property name="age" type="integer">
<column name="personAge"/>
</property>
<!-- 映射引用属性name,引用属性的类型为com.gxd.component.po.Name -->
<component name="name" class="com.gxd.component.po.Name">
<!-- 映射引用属性的firstName值 -->
<property name="firstName"/>
<!-- 映射引用属性的lastName值 -->
<property name="lastName"></property>
</component>
</class>
</hibernate-mapping>
测试：
public static void main(String[] args) {
Operator op = new Operator() ;
Person p = new Person() ;
Name name = new Name() ;
p.setAge(23);
name.setFirstName("刘");
name.setLastName("德华");
p.setName(name) ;
op.addPerson(p);
p = new Person() ;
name = new Name();
p.setAge(18);
name.setFirstName("林") ;
name.setLastName("青霞") ;
p.setName(name) ;
op.addPerson(p);
}
public void addPerson(Person person) {
session.save(person);
session.beginTransaction().commit();
}
结果：
五、 集合引用属性映射
集合除了可以存放字符串外，还可以存放引用类型。
public class Member implements Serializable {
private static final long serialVersionUID =
private int id ;
private String name ;
private int age ;
//存放了引用类型的集合属性 学历
private List<SchoolAge> schoolAge = new ArrayList<SchoolAge>() ;
.......
}
public class SchoolAge {
private String name ; //学校名
private String schoolType ; //学校类型
private String address ; //学校地址
.........
}
Member.hbm.xml
<hibernate-mapping>
<class name="com.gxd.composite.po.Member" table="member">
<id name="id" type="integer">
<column name="memID" />
<generator class="native" />
</id>
<property name="name" type="string">
<column name="memName"></column>
</property>
<property name="age" type="integer">
<column name="memAge"/>
</property>
<!-- 映射List集合属性 -->
<list name="schoolAge" table="school_age">
<!-- 映射关联外键列 -->
<key column="memID"/>
<!-- List有序集合,需要索引 -->
<list-index column="list_order"/>
<!-- 映射集合里的元素并指定类型 -->
<composite-element class="com.gxd.composite.po.SchoolAge">
<!-- 每个property属性映射集合元素的基本属性 -->
<property name="name"/>
<property name="schoolType"/>
<property name="address"/>
</composite-element>
</list>
</class>
</hibernate-mapping>
测试：
public static void main(String[] args) {
Operator op = new Operator() ;
Member member = new Member() ;
SchoolAge schAge = new SchoolAge() ;
member.setName("张三") ;
member.setAge(21) ;
schAge.setName("郴州市一完小") ;
schAge.setSchoolType("小学") ;
schAge.setAddress("郴州市桔井路1号") ;
SchoolAge schAge2 = new SchoolAge() ;
schAge2.setName("郴州市二中") ;
schAge2.setSchoolType("中学") ;
schAge2.setAddress("郴州市苏仙北路2号") ;
member.getSchoolAge().add(schAge) ;
member.getSchoolAge().add(schAge2) ;
op.addMember(member) ;
}
public void addMember(Member member) {
session.save(member);
session.beginTransaction().commit();
}
结果：
未完待续……
- Hibernate Mapping笔记
- Hibernate Mapping笔记
- hibernate-mapping
- Hibernate mapping
- 自己创建 hibernate mapping
- 3-Hibernate mapping file
- HIBERNATE VIEW MAPPING
- hibernate Annotation extend mapping
- Hibernate collection mapping
- hibernate model mapping exception
- Hibernate Mapping Example
- hibernate mapping formula
- Hibernate 之 Mapping
- hibernate mysql text mapping
- hibernate-mapping模板
- hibernate mapping配置详解
- Hibernate 之 Mapping
- <hibernate-mapping>常用配置
- orcale学习中的几个sql
- X Window研究笔记(22)
- 夯实基本功——关于Const
- 庆祝国庆.
- Linux下双网卡绑定技术实现负载均衡和失效保护 （黑否）
- Hibernate Mapping笔记
- 路由器中的内存分类
- 发布两上PHP类(邮件发传及文件上传)
- 十月:入秋醍醐味
- 在Ubuntu上安装RealPlayer（问题总结）
- xx
- ASP.NET程序中常用的三十三种代码
- 数据库---SQL双重否定、函数依赖、关系代数的基本运算
- 编程修养
