1 association

<resultMap type="SysUser" id="SysUserResult">
        <id     property="userId"       column="user_id"      />
        <result property="deptId"       column="dept_id"      />
        <result property="userName"     column="user_name"    />
        <result property="nickName"     column="nick_name"    />
        <result property="remark"       column="remark"       />
        <association property="dept"    column="dept_id" javaType="SysDept" resultMap="deptResult" />
    </resultMap>

    <resultMap id="deptResult" type="SysDept">
        <id     property="deptId"   column="dept_id"     />
        <result property="parentId" column="parent_id"   />
        <result property="deptName" column="dept_name"   />
    </resultMap>

2 collection

<resultMap id="PersonResult" type="Person">
        <result property="personId"    column="person_id"    />
        <result property="name"    column="name"    />
        <result property="remark"    column="remark"    />
    </resultMap>

    <resultMap id="PersonAndCarResult" type="Person" extends="PersonResult">
        <collection property="CarList" notNullColumn="person_id" javaType="java.util.List" resultMap="CarResult" />
    </resultMap>

    <resultMap id="CarResult" type="Car">
        <result property="carId"    column="car_id"    />
        <result property="carName"    column="car_name"    />
        <result property="remark"    column="remark"    />
    </resultMap>

3 一起使用

<resultMap type="SysUser" id="SysUserResult">
        <id     property="userId"       column="user_id"      />
        <result property="deptId"       column="dept_id"      />
        <result property="userName"     column="user_name"    />
        <result property="nickName"     column="nick_name"    />
        <result property="email"        column="email"        />
        <result property="phonenumber"  column="phonenumber"  />
        <result property="sex"          column="sex"          />
        <result property="avatar"       column="avatar"       />
        <result property="password"     column="password"     />
        <result property="status"       column="status"       />
        <result property="delFlag"      column="del_flag"     />
        <result property="loginIp"      column="login_ip"     />
        <result property="loginDate"    column="login_date"   />
        <result property="createBy"     column="create_by"    />
        <result property="createTime"   column="create_time"  />
        <result property="updateBy"     column="update_by"    />
        <result property="updateTime"   column="update_time"  />
        <result property="remark"       column="remark"       />
        <association property="dept"    column="dept_id" javaType="SysDept" resultMap="deptResult" />
        <collection  property="roles"   javaType="java.util.List"        resultMap="RoleResult" />
    </resultMap>

    <resultMap id="deptResult" type="SysDept">
        <id     property="deptId"   column="dept_id"     />
        <result property="parentId" column="parent_id"   />
        <result property="deptName" column="dept_name"   />
        <result property="orderNum" column="order_num"   />
        <result property="leader"   column="leader"      />
        <result property="status"   column="dept_status" />
    </resultMap>

    <resultMap id="RoleResult" type="SysRole">
        <id     property="roleId"       column="role_id"        />
        <result property="roleName"     column="role_name"      />
        <result property="roleKey"      column="role_key"       />
        <result property="roleSort"     column="role_sort"      />
        <result property="dataScope"     column="data_scope"    />
        <result property="status"       column="role_status"    />
    </resultMap>