MybatisPlus学习-添加额外的SQL查询

说明

与mybatis原本的SQL查询相似，通过mapper类，mapper.xml添加

在自己写的mapper接口中添加方法

@Repository
public interface UserMapper extends BaseMapper<User> {

    public User selectByUserName(String username);
}

编写mapper.xml文件

<?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.gui.mapper.UserMapper">

    <select id="selectByUserName" resultType="com.gui.pojo.User">
        select * from user where username = #{username}
    </select>


</mapper>

在配置文件application中的添加mapper.xml的路径

mybatis-plus.mapper-locations=classpath:mapper/*.xml

测试使用