Mybatis CRUD实例

实例的开发环境

项目的目录结构

log4j.properties配置

# Global logging configuration
#在开发环境下日志要设置成Debug,生产环境设置成info或error
log4j.rootLogger&＃61;DEBUG, stdout
# Console output...
log4j.appender.stdout&＃61;org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout&＃61;org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern&＃61;%5p [%t] - %m%n

SqlMapConfig.xml的配置

    这是一个关键的配置文件&＃xff0c;是mybaits的全局配置文件&＃xff0c;不过名称不固定&＃xff0c;主要是用来配置数据源、事务等&＃xff0c;mybaits的运行环境。


PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">


创建POJO类

package cn.itcast.mybatis.po;import java.util.Date;public class User {private int id;private String username;// 用户姓名private String sex;// 性别private Date birthday;// 生日private String address;// 地址public int getId() {return id;}public void setId(int id) {this.id &＃61; id;}public String getUsername() {return username;}public void setUsername(String username) {this.username &＃61; username;}public String getSex() {return sex;}public void setSex(String sex) {this.sex &＃61; sex;}public Date getBirthday() {return birthday;}public void setBirthday(Date birthday) {this.birthday &＃61; birthday;}public String getAddress() {return address;}public void setAddress(String address) {this.address &＃61; address;}&＃64;Overridepublic String toString() {return "User [id&＃61;" &＃43; id &＃43; ", username&＃61;" &＃43; username &＃43; ", sex&＃61;" &＃43; sex&＃43; ", birthday&＃61;" &＃43; birthday &＃43; ", address&＃61;" &＃43; address &＃43; "]";}}

映射文件

    映射文件的命名最好规范统一下&＃xff0c;本实例中命名为User.xml载映射文件中配置sql语句。


PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
select * from user where id &＃61; #{id}select * from user where username like &＃39;%${value}%&＃39; select LAST_INSERT_ID()insert into user(username,birthday,sex,address) values(#{username},#{birthday},#{sex},#{address})delete from user where id&＃61;#{id}update user set username&＃61;#{username},birthday&＃61;#{birthday},sex&＃61;#{sex},address&＃61;#{address} where id&＃61;#{id}



并在SqlMapConfig.xml文件中加载映射文件

具体代码实现

    接下来就是具体的代码实现了&＃xff0c;在MybatisFirst类中&＃xff1a;

package cn.itcast.mybatis.first;import java.io.IOException;
import java.io.InputStream;
import java.util.Date;
import java.util.List;import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Before;
import org.junit.Test;import cn.itcast.mybatis.po.User;public class MybatisFirst {//创建会话工厂private SqlSessionFactory sqlSessionFactory;&＃64;Beforepublic void createSqlSessionFactory() throws IOException{//配置文件String resource&＃61;"SqlMapConfig.xml";//得到配置文件流InputStream inputStream&＃61;Resources.getResourceAsStream(resource);// 使用SqlSessionFactoryBuilder从xml配置文件中创建SqlSessionFactorysqlSessionFactory&＃61;new SqlSessionFactoryBuilder().build(inputStream);}&＃64;Testpublic void findUserByIdTest() throws IOException{SqlSession sqlSession&＃61;null;try {//创建数据库会话实例sqlSession&＃61;sqlSessionFactory.openSession();//根据用户ID查询单个记录User user&＃61;sqlSession.selectOne("test.findUserById", 1);System.out.println(user);} catch (Exception e) {e.printStackTrace();} finally {if (sqlSession !&＃61; null) {sqlSession.close();}}}&＃64;Testpublic void findUserByUsername() throws IOException{SqlSession sqlSession&＃61;null;try {//创建数据库会话实例sqlSession&＃61;sqlSessionFactory.openSession();//根据用户名查询多条记录List list&＃61;sqlSession.selectList("test.findUserByUsername","张");System.out.println(list);} catch (Exception e) {e.printStackTrace();} finally {if (sqlSession !&＃61; null) {sqlSession.close();}}}&＃64;Testpublic void testInsert(){SqlSession sqlSession&＃61;null;try {sqlSession&＃61;sqlSessionFactory.openSession();User user&＃61;new User();user.setAddress("廊坊市广阳区");user.setBirthday(new Date());user.setSex("1");user.setUsername("张令");sqlSession.insert("test.insertUser",user);//提交事务sqlSession.commit();} catch (Exception e) {e.printStackTrace();}finally{if(sqlSession!&＃61;null){sqlSession.close();}}}&＃64;Testpublic void testDelete(){SqlSession sqlSession&＃61;null;try {sqlSession&＃61;sqlSessionFactory.openSession();sqlSession.delete("test.deleteUserById",29);//提交事务sqlSession.commit();} catch (Exception e) {e.printStackTrace();}finally{if(sqlSession!&＃61;null){sqlSession.close();}}}&＃64;Testpublic void testUpdate(){SqlSession sqlSession&＃61;null;try {sqlSession&＃61;sqlSessionFactory.openSession();User user&＃61;new User();user.setId(26);user.setAddress("河北省南宫市");user.setBirthday(new Date());user.setSex("男");user.setUsername("令仔");sqlSession.update("test.updateUser",user);//提交事务sqlSession.commit();} catch (Exception e) {e.printStackTrace();}finally{if(sqlSession!&＃61;null){sqlSession.close();}}}}