settings

• settings包含很多重要的设置项
  • setting:用来设置每一个设置项
  • name:设置项名
  • value:设置项取值

mapUnderscoreToCamelCase

• 开启驼峰命名法

  <settings><setting name="mapUnderscoreToCamelCase" value="true"/></settings>

Employee:

package com.atguigu.mybatis.bean;public class Employee {private Integer id;private String lastName;private String email;private String gender;
}

EmployeeMapper.xml:

<?xml version="1.0" encoding="UTF-8" ?><!DOCTYPE mapperPUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.atguigu.mybatis.dao.EmployeeMapper"><select id="getEmpById" resultType="com.atguigu.mybatis.bean.Employee">select id,last_name ,email,gender from tb1_employee where id = #{id}</select>
</mapper>

bean的lastName可以与数据库的last_name映射上了！