MyBatis字段名和属性名不一致的解决方法

<mapper namespace="com.atguigu.mybatis.mapper.EmpMapper">
 
<!--    字段名跟属性名不一致情况下，如何处理映射关系-->
<!--      Emp getEmpById(@Param("empId") Integer empId);-->
    <select id="getEmpById" resultType="Emp">
<!--方式一：给字段起别名，和属性名保持一致-->
   select  emp_id empId,emp_name empName,age,gender from t_emp where emp_id=#{empId}
    </select>
</mapper>

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

<!--  设置全局配置 将下划线映射为驼峰 -->
<!--emp_id-empId； emp_Name-empName    -->
    <settings>
        <setting name="mapUnderscoreToCamelCase" value="true"/>
    </settings>

<select id="getEmpById" resultType="Emp">
    select * from t_emp where emp_id=#{empId}
    </select>

    <resultMap id="empResultMap" type="Emp">
        <id column="emp_id" property="empId"></id>
        <result column="emp_name" property="empName"></result>
        <result column="age" property="age"></result>
        <result column="gender" property="gender"></result>
    </resultMap>
 
    <select id="getEmpById" resultMap="empResultMap">
        select * from t_emp where emp_id=#{empId}
    </select>