<settings>

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

        <!--开启懒加载(开启延迟加载)-->

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

        <!--关闭实时加载-->

        <setting name="aggressiveLazyLoading" value="false"/>

    </settings>

<resultMap id="empAndDeptByStepResultMap" 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>

        <!--

           fetchType：lazy懒加载，eager立即加载

        -->

        <association property="dept"

                     column="dept_id"

                     select="org.example.mapper.DeptMapper.getEmpAndDeptByStepTwo" fetchType="lazy">

            <id column="dept_id" property="deptId"></id>

            <result column="dept_name" property="deptName"></result>

        </association>

    </resultMap>