第一个Mybatis程序

1. 新建数据库和表

CREATE DATAbase `mybatis`;

USE `mybatis`;

CREATE TABLE `user`(
	`id` INT(20) NOT NULL PRIMARY key,
	`name` VARCHAR(30) DEFAULT NULL,
	`pwd` VARCHAR(30) DEFAULT NULL
)ENGINE=INNODB DEFAULT CHARSET=utf8;

INSERT INTO `user` (id,name,pwd) 
VALUES (1,'mm1','mm1pwd'),
(2,'mm2','mm1pwd'),
(3,'mm3','mm1pwd');

2. 新建一个maven项目
3. 删除src
4. 导入依赖

    

        
        
            mysql
            mysql-connector-java
            8.0.23
        
        
        
        
            org.mybatis
            mybatis
            3.4.6
        
        
        
        
            junit
            junit
            4.12
            test
        
    

5.mybatis核心配置文件

6. 编写mybatis工具类

// sqlSessionFactory
public class MybatisUtil {
    private static SqlSessionFactory sqlSessionFactory = null;

    static{
        try {
            String resource = "org/mybatis/example/mybatis-config.xml";
            InputStream inputStream = Resources.getResourceAsStream(resource);
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    public static SqlSession getSqlSession(){
        return sqlSessionFactory.openSession();
    }
}

7.编写pojo类

public class User implements Serializable {
    private Integer id;
    private String name;
    private String pwd;
    }

8编写dao接口

public interface UserDao {
    List getUserList();
}

9.编写UserDao.xml

    
        select * from mybatis.user
    

10.在核心配置文件中注册mapper

11.编写测试类

    @Test
    public void test(){
        SqlSession sqlSession = MybatisUtil.getSqlSession();
        UserDao userDao = sqlSession.getMapper(UserDao.class);
        List userList = userDao.getUserList();
        System.out.println(userList.toString());
        sqlSession.close();
    }