实现用户和角色关联功能 配置

<!--  两表关联 -->
   <composite-id name="userRoleRelationid"
      class="com.fh.model.userRoleRelation.UserRoleRelation">
   
         <!-- 用户表 -->
      <key-many-to-one name="userId" lazy="false"
         class="com.fh.model.user.User">
         <column name="user_Id"></column>
      </key-many-to-one>

         <!-- 角色表 -->
      <key-many-to-one name="roleId" lazy="false"
         class="com.fh.model.user.Role">
         <column name="role_Id"></column>
      </key-many-to-one>

    <!--  userId为String类型 -->
   <!-- <key-property name="userId" type="java.lang.String"> 
            <olumn name="user_id" length="32"></column> 
      </key-property> -->
   </composite-id>
</class>