Mybatis（一）基本配置和增加sql

<?xml version="1.0" encoding="UTF-8"?>
<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/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.example</groupId>
    <artifactId>mybatis</artifactId>
    <packaging>pom</packaging>
    <version>1.0-SNAPSHOT</version>
    <modules>
        <module>mybatis1</module>
    </modules>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>

    <dependencies>
        <!--mybatis依赖-->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.7</version>
        </dependency>
        <!--数据库连接-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.32</version>
        </dependency>
        <!--测试-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>
    </dependencies>
</project>

<!-- 声明xml的版本号和编码类型-->
<?xml version="1.0" encoding="UTF-8" ?>

<!-- 设置mybatis约束 -->
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>

<!-- 设置数据库的环境 -->
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>       //事务管理器，类型JDBC
            <dataSource type="POOLED">              //数据源，pooled表示数据库连接池
                <property name="driver" value="com.mysql.jdbc.Driver"/>  //驱动名称
                //链接地址
                <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=true&amp;useUnicode=true&amp;characterEncoding=UTF-8"/>
                //数据库账号和密码（按实际情况来）
                <property name="username" value="root"/>
                <property name="password" value="123456"/>
            </dataSource>
        </environment>
    </environments>
    
<!--    引入映射文件-->
    <mappers>
        <mapper resource="mappers/UserMapper.xml"/>
    </mappers>
    
</configuration>

CREATE TABLE IF NOT EXISTS `t_user`  (
  `id` int(20) NOT NULL,
  `username` varchar(30) DEFAULT NULL,
  `password` varchar(30) DEFAULT NULL,
  `age` int(11) DEFAULT NULL,
  `sex` char(1) DEFAULT NULL,
  `email` varchar(20) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE = InnoDB CHARACTER SET = utf8;

package com.mlzx.entity;

public class User {
    private Integer id;

    private String username;

    private String password;

    private Integer age;

    private String sex;

    private String email;
}

package com.mlzx.mapper;

public interface UserMapper {
    //添加用户
    int addUser();
}

<?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.mlzx.mapper.UserMapper">
    <insert id="addUser">
        insert into t_user value(1, 'admin', '12345', 23, '男'，'1234@qq.com')
    </insert>
</mapper>

package com.mlzx.mapper;

import com.mlzx.entity.User;
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.Test;

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

public class UserMapperTest {

    @Test
    public void testAddUser() throws IOException {
        //加载核心配置文件
        InputStream inputStream = Resources.getResourceAsStream("mybatis-config.xml");
        //获取SqlSessionFactoryBuilder
        SqlSessionFactoryBuilder sqlSessionFactoryBuilder = new SqlSessionFactoryBuilder();
        //获取SqlSessionFactory
        SqlSessionFactory sqlSessionFactory = sqlSessionFactoryBuilder.build(inputStream);
        //获取sqlsession,其中sqlSession代表Java程序和数据库之间的对话
        SqlSession sqlSession = sqlSessionFactory.openSession();
        //获取mapper接口对象
        UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
        //测试功能，其中res代表的是受影响的行数
        int res = userMapper.addUser(); 
        //提交事务
        sqlSession.commit();

        System.out.println("result:" + res);
    }
}