Mybatis first acquaintance (1)

1. Review the database first

https://blog.csdn.net/xfb1989/article/details/102404898

 

2. Configuration file

<?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="development1">
        <environment id="development1">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/1803_mybatis?serverTimezone=GMT%2B8"/>
                <property name="username" value="root"/>
                <property name="password" value="123456"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="com/qf/mybatis/mapper/LogMapper.xml"/>
    </mappers>
</configuration>

 Implement the entity class corresponding to the database

Implement the mapping file

<?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.qf.mybatis.mapper.LogMapper">

    <select id="selectLog" resultType="com.qf.mybatis.entity.Log">

     select id, content, create_time as createTime, flag from t_log where id = #{id}

     </select>

</mapper>

Implement the interface file

package com.qf.mybatis.mapper;

import com.qf.mybatis.entity.Log;

public interface LogMapper  {

    public Log selectLog(int id);
}

 test

package test.controller;

import com.qf.mybatis.entity.Log;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Test;

import java.io.IOException;
import java.io.InputStream;

public class MybatisTest {
    
    @Test
    public void selectClassTest() throws IOException{
        String resource = "mybaties-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);

        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession sqlSession = sqlSessionFactory.openSession();
        Log log = sqlSession.selectOne("com.qf.mybatis.mapper.LogMapper.selectLog", 1);
        System.out.println("selectClassTest log " + log.toString());

    }
}