帝国CMS显示指定时间内更新的信息数量

帝国CMS显示指定时间内更新的信息数量，如1天内列新多少条信息：
用sql调用
12小时：<?=$empire->gettotal(select count(*) as total from phome_ecms_表 where newstime>UNIX_TIMESTAMP()-24*3600)?>
6小时：<?=$empire->gettotal(select count(*) as total from phome_ecms_表 where newstime>UNIX_TIMESTAMP()-6*3600)?>