慕课网-Hibernate初探之单表映射 学习

先给eclipse安装hibernate插件

打开eclipse工具，选择HELP---Install new software----输入网址

http://download.jboss.org/jbosstools/updates/development

安装Hibernate Tools

初探Hibernate

Students.java

需要 

1.参数私有化

2.一个无参构造函数

3.需要所有参数的setter/getter方法

import java.util.Date;public class Students {private int sid;private String sname;private String gender;private Date birthday;private String address;public Students() {super();}public int getSid() {return sid;}public void setSid(int sid) {this.sid = sid;}public String getSname() {return sname;}public void setSname(String sname) {this.sname = sname;}public String getGender() {return gender;}public void setGender(String gender) {this.gender = gender;}public Date getBirthday() {return birthday;}public void setBirthday(Date birthday) {this.birthday = birthday;}public String getAddress() {return address;}public void setAddress(String address) {this.address = address;}@Overridepublic String toString() {return "Students [sid=" + sid + ", sname=" + sname + ", gender=" + gender + ", birthday=" + birthday+ ", address=" + address + "]";}}

hibernate.cfg.xml

原来数据库中没有Students表。不过没关系。

hbm2ddl.auto是create。

意思是每次插入数据前，都要先dop，再create

<?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.username">root</property>    <property name="connection.password">root</property>    <property name="connection.driver_class">com.mysql.jdbc.Driver</property>    <property name="connection.url">jdbc:mysql:///hibernate?useUnicode=true&characterEncoding=UTF-8</property><property name="dialect">org.hibernate.dialect.MySQLDialect</property>    <property name="show_sql">true</property>    <property name="format_sql">true</property>    <property name="hbm2ddl.auto">create</property>    <mapping resource="Students.hbm.xml"/>    </session-factory></hibernate-configuration>

Students.hbm.xml

这个是自动生成的。

<?xml version="1.0"?><!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN""http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"><!-- Generated 2017-4-28 16:17:27 by Hibernate Tools 3.4.0.CR1 --><hibernate-mapping>    <class name="Students" table="STUDENTS">        <id name="sid" type="int">            <column name="SID" />            <generator class="assigned" />        </id>        <property name="sname" type="java.lang.String">            <column name="SNAME" />        </property>        <property name="gender" type="java.lang.String">            <column name="GENDER" />        </property>        <property name="birthday" type="java.util.Date">            <column name="BIRTHDAY" />        </property>        <property name="address" type="java.lang.String">            <column name="ADDRESS" />        </property>    </class></hibernate-mapping>

测试类

import java.util.Date;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.Transaction;import org.hibernate.cfg.Configuration;import org.hibernate.service.ServiceRegistry;import org.hibernate.service.ServiceRegistryBuilder;import org.junit.After;import org.junit.Before;import org.junit.Test;public class StudentsTest {private SessionFactory sessionFactory;private Session session;private Transaction transaction;@Beforepublic void init(){//创建配置对象Configuration config = new Configuration().configure();//创建服务注册对象ServiceRegistry serviceRegistry = new ServiceRegistryBuilder().applySettings(config.getProperties()).buildServiceRegistry();//创建会话工厂对象sessionFactory = config.buildSessionFactory(serviceRegistry);//会话对象session = sessionFactory.openSession();//开启事务transaction = session.beginTransaction();}@Afterpublic void destory(){//提交事务transaction.commit();//关闭会话session.close();//关闭sessionFactorysessionFactory.close();}@Testpublic void testSaveStudents() {Students s = new Students();s.setSid(3);s.setSname("张三丰");s.setGender("男");s.setBirthday(new Date());s.setAddress("武当山");//保存对象到数据库session.save(s);}}

运行结果

Hibernate:     drop table if exists STUDENTSHibernate:     create table STUDENTS (        SID integer not null,        SNAME varchar(255),        GENDER varchar(255),        BIRTHDAY datetime,        ADDRESS varchar(255),        primary key (SID)    )Hibernate:     insert     into        STUDENTS        (SNAME, GENDER, BIRTHDAY, ADDRESS, SID)     values        (?, ?, ?, ?, ?)

同时查看数据库，会发现一条记录

2-5 Session详解(上)

注意如果是openSession，需要每次都要手动关闭Session，

如果是getCurrentSession,会自动关闭Session

2-7 hbm配置文档

通常使用的是native。和assigned

3-2.单一主键


3-3.基本类型

xxx.hbm.xml

如果想要“年月日，时分秒”，type="java.util.date"或者type="timestamp"

如果想要“年月日”，type="date"

如果想要“时分秒”，type="time"

注意timestamp,date,time都是hibernate类型

3-4.对象类型


3-5.组件属性


3-6.单表操作CRUD实例

import java.util.Date;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.Transaction;import org.hibernate.cfg.Configuration;import org.hibernate.service.ServiceRegistry;import org.hibernate.service.ServiceRegistryBuilder;import org.junit.After;import org.junit.Before;import org.junit.Test;public class StudentsTest {private SessionFactory sessionFactory;private Session session;private Transaction transaction;@Beforepublic void init(){//创建配置对象Configuration config = new Configuration().configure();//创建服务注册对象ServiceRegistry serviceRegistry = new ServiceRegistryBuilder().applySettings(config.getProperties()).buildServiceRegistry();//创建会话工厂对象sessionFactory = config.buildSessionFactory(serviceRegistry);//会话对象session = sessionFactory.openSession();//开启事务transaction = session.beginTransaction();}@Afterpublic void destory(){//提交事务transaction.commit();//关闭会话session.close();//关闭sessionFactorysessionFactory.close();}@Testpublic void testSaveStudents() {Students s = new Students();s.setSname("张三丰");s.setGender("男");s.setBirthday(new Date());s.setAddress("武当山");//保存对象到数据库session.save(s);}@Testpublic void testGetStudents(){Students s = (Students)session.get(Students.class, 0);//System.out.println(s);}@Testpublic void testLoadStudents(){Students s = (Students)session.load(Students.class, 0);//System.out.println(s);}@Testpublic void testUpdateStudents(){Students s = (Students)session.get(Students.class, 0);s.setGender("女");session.update(s);System.out.println(s);}@Testpublic void testDeleteStudents(){Students s = (Students)session.get(Students.class, 0);session.delete(s);}}