MyBatis-practice-04

lombook插件

@Data//lombook注解,实现get() set()方法 toString()方法

User:

@Data//lombook注解,实现get() set()方法 toString()方法
public class User {

    private Integer id;
    private String username;
    private String password;
}

UserMapper

public interface UserMapper {

    int insert(User user);

    int update(User user);

    int delete(Integer id);

    User selectById(Integer id);

    List<User> selectAll();
}

mybatis-config.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>
    <settings>
        <setting name="mapUnderscoreToCamelCase" value="true"/>      <!--开启驼峰自动映射-->
        <setting name="logImpl" value="STDOUT_LOGGING"/>        <!--开启日志输出，选择使用system进行控制台输出-->
    </settings>

    <typeAliases>
        <package name="com.dc.pojo"/>
    </typeAliases>

    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"></transactionManager>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/mybatis-example"/>
                <property name="username" value="root"/>
                <property name="password" value="root"/>
            </dataSource>
        </environment>
    </environments>

    <mappers>
        <mapper resource="mappers/UserMapper.xml"></mapper>
    </mappers>

</configuration>

UserMapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "https://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace="com.dc.mapper.UserMapper">
    <insert id="insert" useGeneratedKeys="true" keyProperty="id" keyColumn="id">
        insert into user(username,password) value(#{
   username},#{
   password})
    </insert>
    <update id="update">
        update user set username=#{
   username},password=#{
   password} where id=#{
   id}
    </update>
    <delete id="delete">
        delete from user where id=#{
   id}
    </delete>
    <select id="selectById" resultType="com.dc.pojo.User">
        select * from user where id=#{
   id}
    </select>
    <select id="selectAll" resultType="com.dc.pojo.User">
        select * from user
    </select>
</mapper>

测试

public class Test {

    @org.junit.jupiter.api.Test
    public void test() throws IOException {

        InputStream ips = Resources.getResourceAsStream("mybatis-config.xml");

        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(ips);

        SqlSession sqlSession = sqlSessionFactory.openSession(true);

        UserMapper mapper = sqlSession.getMapper(UserMapper.class);

        User user=new User();
        user.setUsername("lili");
        user.setPassword("3333");

        mapper.insert(user);
//        mapper.update(user);
//        mapper.delete(1);
//        User user1=mapper.selectById(2);
//        List<User> user1=mapper.selectAll();
//        System.out.println(user1);
        sqlSession.close();
    }


}

原文链接: https://blog.csdn.net/qq_53568730/article/details/135444775