mapper里面的案例：
<select id="querySupportingPolicies" resultmap="data,count" resulttype="java.util.List">
select * from AAA_policy order by create_time desc limit #{pageNum} , #{pageSize};
select FOUND_ROWS() as count;
</select>
JAVA中处理：
List<list<?>> list = businessMapper.querySupportingPolicies(num,vo.getPageSize());
PageInfo pageInfo = new PageInfo(list.get(0));
pageInfo.setTotal((Integer)list.get(1).get(0));
return pageInfo;