hibernate_07_单表操作_增删改操作

首先，创建类对象

 package com.imooc.hibernate;

 public class Address {

     private String postcode; //邮编
     private String phone; //电话
     private String address; //地址

     public Address() {};

     public String getPostcode() {
         return postcode;
     }
     public void setPostcode(String postcode) {
         this.postcode = postcode;
     }
     public String getPhone() {
         return phone;
     }
     public void setPhone(String phone) {
         this.phone = phone;
     }
     public String getAddress() {
         return address;
     }
     public void setAddress(String address) {
         this.address = address;
     }
     public Address(String postcode, String phone, String address) {
 //        super();
         this.postcode = postcode;
         this.phone = phone;
         this.address = address;
     }
     @Override
     public String toString() {
         return "Address [postcode=" + postcode + ", phone=" + phone + ", address=" + address + "]";
     }

 }

 package com.imooc.hibernate;

 import java.sql.Blob;
 import java.util.Date;

 public class Students {

     private int sid;
     private String sname;
     private String gender;
     private Date birthday;
     private Address address;
     private Blob picture;

     public Blob getPicture() {
         return picture;
     }

     public void setPicture(Blob picture) {
         this.picture = picture;
     }

     public Students() {}

     public Students(int sid, String sname, String gender, Date birthday, Address address, Blob picture) {
         super();
         this.sid = sid;
         this.sname = sname;
         this.gender = gender;
         this.birthday = birthday;
         this.address = address;
         this.picture = picture;
     }

     @Override
     public String toString() {
         return "Students [sid=" + sid + ", sname=" + sname + ", gender=" + gender + ", birthday=" + birthday
                 + ", address=" + address + ", picture=" + picture + "]";
     }

     public Address getAddress() {
         return address;
     }

     public void setAddress(Address address) {
         this.address = address;
     }

     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;
     }

 }

创建类对象的配置文件

 <?xml version="1.0"?>
 <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
 "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
 <!-- Generated 2017-5-23 0:24:09 by Hibernate Tools 3.5.0.Final -->
 <hibernate-mapping>
     <class name="com.imooc.hibernate.Students" table="STUDENTS">
         <id name="sid" type="int">
             <column name="SID" />
             <generator class="native" />
         </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="picture" type="java.sql.Blob">
             <column name="PICTURE" />
         </property>

         <component name="address" class="com.imooc.hibernate.Address">
             <property name="postcode" column="POSTCODE"/>
             <property name="phone" column="PHONE"/>
             <property name="address" column="ADDRESS"/>
         </component>
     </class>
 </hibernate-mapping>

创建hibernate配置文件

 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE hibernate-configuration PUBLIC
         "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
         "http://www.hibernate.org/dtd/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://localhost:3306/hibernate?useUnicode=true&amp;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">update</property>

         <mapping resource="com/imooc/hibernate/Students.hbm.xml"/>
     </session-factory>
 </hibernate-configuration>

创建测试类

 package com.icoom.test;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.sql.Blob;
 import java.util.Date;

 import org.hibernate.Hibernate;
 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;

 import com.imooc.hibernate.Address;
 import com.imooc.hibernate.Students;

 public class StudentsTest {

     private SessionFactory sessionFactory;
     private Session session;
     private Transaction transaction;

     @Before
     public void init() {
         // 1.创建配置对象
         Configuration config = new Configuration().configure();
         // 2.创建服务注册对象
         ServiceRegistry serviceRegistry = new ServiceRegistryBuilder().applySettings(config.getProperties()).buildServiceRegistry();
         // 3.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();
     }

     @After
     public void destory() {
         transaction.commit(); //提交事务
         session.close(); //关闭session
         sessionFactory.close();//关闭会话工厂
     }

     @Test
     public void testSaveStudents() {
         Students s = new Students();
         s.setSid(1);
         s.setSname("老张");
         s.setGender("男");
         s.setBirthday(new Date());
         Address address = new Address("250000", "1310531xxxx", "山东济南");
         s.setAddress(address);
         session.save(s);//保存对象进入数据库
     }

     @Test
     public void testGetStudents() {
         Students s = (Students) session.get(Students.class, 1);
         System.out.println(s);
     }

     @Test
     public void testLoadStudents() {
         Students s = (Students) session.load(Students.class, 1);
         System.out.println(s);
     }

     @Test
     public void testUpdateStudents() {
         Students s = (Students) session.get(Students.class, 1);
         s.setGender("女");
         session.update(s);
     }

     @Test
     public void testDeleteStudents() {
         Students s = (Students) session.get(Students.class, 1);
         session.delete(s);
     }
 }

get和load方法的区别

1. 在不考虑缓存的情况下，get方法会在调用之后立即向数据库发出sql语句，返回持久化对象；load方法会在调用后放回一个代理对象。该代理对象只保存了实体对象的id，知道使用对象的非主键属性时才会发出sql语句。
2. 查询数据库中不存在的数据时，get方法返回null，load方法抛出org.hibernate.ObjectNotFoundException异常。