hibernate入门
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2024-03-23 13:11:58
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Hibernate简介
ORM框架/持久层框架 jdbc的一个框架
object reference mapping
通过管理对象来改变数据库中的数据
通过管理对象来操作数据库
mybatis
优势:跨数据库的无缝移植
新建maven工程
配置pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.lcf</groupId>
<artifactId>hibernate</artifactId>
<packaging>war</packaging>
<version>0.0.1-SNAPSHOT</version>
<name>hibernate Maven Webapp</name>
<url>http://maven.apache.org</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
<junit.version>4.12</junit.version>
<servlet.version>4.0.0</servlet.version>
<hibernate.version>5.3.0.Final</hibernate.version>
<mysql.driver.version>5.1.46</mysql.driver.version>
</properties>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>${junit.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>${servlet.version}</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>${hibernate.version}</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>${mysql.driver.version}</version>
</dependency>
</dependencies>
<build>
<finalName>hibernate</finalName>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.7.0</version>
<configuration>
<source>${maven.compiler.source}</source>
<target>${maven.compiler.target}</target>
<encoding>${project.build.sourceEncoding}</encoding>
</configuration>
</plugin>
</plugins>
</build>
</project>
配置文件
在resources文件夹下新建hibernate.cfg.xml :
<?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>
<!-- 1. 数据库相关 -->
<property name="connection.username">root</property>
<property name="connection.password">123</property>
<property name="connection.url">jdbc:mysql://localhost:3306/t226?useUnicode=true&characterEncoding=UTF-8
</property>
<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="dialect">org.hibernate.dialect.MySQLDialect</property>
<!-- 配置本地事务(No CurrentSessionContext configured!) -->
<property name="hibernate.current_session_context_class">thread</property>
<!-- 2. 调试相关 -->
<property name="show_sql">true</property>
<property name="format_sql">true</property>
</session-factory>
</hibernate-configuration>
在开发阶段再创建实体类和实体映射文件(*.hbm.xml)
public class User implements Serializable{
/**
*
*/
private static final long serialVersionUID = 1L;
private Integer id;
private String userName;
private String userPwd;
private String sex;
private Date birthday;
private String realName;
private Timestamp createDatetime;
private String remark;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public String getUserPwd() {
return userPwd;
}
public void setUserPwd(String userPwd) {
this.userPwd = userPwd;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public Date getBirthday() {
return birthday;
}
public void setBirthday(Date birthday) {
this.birthday = birthday;
}
public String getRealName() {
return realName;
}
public void setRealName(String realName) {
this.realName = realName;
}
public Timestamp getCreateDatetime() {
return createDatetime;
}
public void setCreateDatetime(Timestamp createDatetime) {
this.createDatetime = createDatetime;
}
public String getRemark() {
return remark;
}
public void setRemark(String remark) {
this.remark = remark;
}
public User() {
super();
}
public User(String userName, String userPwd, String sex, Date birthday, String realName,
Timestamp createDatetime, String remark) {
super();
this.userName = userName;
this.userPwd = userPwd;
this.sex = sex;
this.birthday = birthday;
this.realName = realName;
this.createDatetime = createDatetime;
this.remark = remark;
}
@Override
public String toString() {
return "User [id=" + id + ", userName=" + userName + ", userPwd=" + userPwd + ", sex=" + sex + ", birthday="
+ birthday + ", realName=" + realName + ", createDatetime=" + createDatetime + ", remark=" + remark
+ "]";
}
}
实体类对象对应的配置文件User.hbm.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<!--
class标签中:
name:是实体类的全路径,table:实体类对应的数据库中的表
id标签:
name:是实体类中的属性(映射的是表中的主键字段),type:属性对应的类型,columu:属性对应的表中的哪一个列段
property标签:
name:是实体类中的属性(映射的是表中的非主键字段),type:属性对应的类型,columu:属性对应的表中的哪一个列段
-->
<class name="com.lcf.one.entity.User" table="t_hibernate_user">
<id name="id" type="java.lang.Integer" column="id">
<generator class="increment" />
</id>
<property name="userName" type="java.lang.String" column="user_name">
</property>
<property name="userPwd" type="java.lang.String" column="user_pwd">
</property>
<property name="realName" type="java.lang.String" column="real_name">
</property>
<property name="sex" type="java.lang.String" column="sex">
</property>
<property name="birthday" type="java.sql.Date" column="birthday">
</property>
<property insert="false" update="false" name="createDatetime"
type="java.sql.Timestamp" column="create_datetime">
</property>
<property name="remark" type="java.lang.String" column="remark">
</property>
</class>
</hibernate-mapping>
Demo
查询QueryDemo
package com.li.one.demo;
import java.util.List;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
/**
* hibernate查询演示
*
* @author Dragon
*
*/
public class QueryDemo {
public static void main(String[] args) {
Configuration configure = new Configuration().configure("/hibernate.cfg.xml");
SessionFactory sessionFactory = configure.buildSessionFactory();
// 这里的会话指的是操作数据库的链接
Session session = sessionFactory.openSession();
List list = session.createQuery("from User").list();
for (Object obj : list) {
System.out.println(obj);
}
session.close();
}
}
增加
public class InsertDemo {
public static void main(String[] args) {
Configuration configure = new Configuration().configure("/hibernate.cfg.xml");
SessionFactory sessionFactory = configure.buildSessionFactory();
Session session = sessionFactory.openSession();
Transaction transaction = session.beginTransaction();
session.save(new User("狗子", "222", 1));
transaction.commit();
session.close();
}
}
修改
public static void main(String[] args) {
Configuration configure = new Configuration().configure("/hibernate.cfg.xml");
SessionFactory sessionFactory = configure.buildSessionFactory();
Session session = sessionFactory.openSession();
Transaction transaction = session.beginTransaction();
User user = session.get(User.class,4);
user.setUser_name("嬲爆");
System.out.println(user);
transaction.commit();
session.close();
}
删除
public static void main(String[] args) {
Configuration configure = new Configuration().configure("/hibernate.cfg.xml");
SessionFactory sessionFactory = configure.buildSessionFactory();
Session session = sessionFactory.openSession();
Transaction transaction = session.beginTransaction();
User user=new User();
user.setUser_id(4);
session.delete(user);
transaction.commit();
session.close();
}
hibernate管理对象的三种状态
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