Mybatis 入门（）基本使用方法

1.添加jar包

【mybatis】

mybatis-3.1.1.jar

【MYSQL 驱动包】

mysql-connector-java-5.1.7-bin.jar

 

2.建库+建表

create database mybatis;

use mybatis;

CREATE TABLE users(id INT PRIMARY KEY AUTO_INCREMENT, NAME

VARCHAR(20), age INT);

INSERT INTO users(NAME, age) VALUES('Tom', 12);

INSERT INTO users(NAME, age) VALUES('Jack', 11);

 

3.添加Mybatis的配置文件conf.xml

 

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN"

"http://mybatis.org/dtd/mybatis-3-config.dtd">

<configuration>

<environments default="development">

<environment id="development">

<transactionManager type="JDBC" />

<dataSource type="POOLED">

<property name="driver" value="com.mysql.jdbc.Driver" />

<property name="url" value="jdbc:mysql://localhost:3306/mybatis" />

<property name="username" value="root" />

<property name="password" value="root" />

</dataSource>

</environment>

</environments>

</configuration>

 

4.定义表对应的实体类

public class User {

private int id;

private String name;

private int age;

//get,set 方法

}

 

5.定义操作users表的sql映射文件userMapper.xml

<?xml version="1.0" encoding="UTF-8" ?>

<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"

"http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace=" com.atguigu.mybatis_test.test1.userMapper">

<select id="getUser" parameterType="int"

resultType="com.atguigu.mybatis_test.test1.User">

select * from users where id=#{id}

</select>

</mapper>

 

6.在conf.xml文件中注册userMapper.xml文件

<mappers>

<mapper resource="com/atguigu/mybatis_test/test1/userMapper.xml"/>

</mappers>

 

7.编写测试代码：执行定义的语句

 

public class Test {

public static void main(String[] args) throws IOException {

String resource = "conf.xml";

//加载 mybatis 的配置文件（它也加载关联的映射文件）

Reader reader = Resources.getResourceAsReader(resource);

//构建 sqlSession 的工厂

SqlSessionFactory sessionFactory = new

SqlSessionFactoryBuilder().build(reader);

//创建能执行映射文件中 sql 的 sqlSession

SqlSession session = sessionFactory.openSession();

//映射 sql 的标识字符串

String statement = "com.atguigu.mybatis.bean.userMapper"+".selectUser";

//执行查询返回一个唯一 user 对象的 sql

User user = session.selectOne(statement, 1);

System.out.println(user);

}

}