SELECT * FROM 订单 where 货主地区 is not null and 应付金额 is not null ${if(len(area)>0," and 货主地区='"+area+"'","")} order by 货主地区,订单ID limit ${if(fr_pagenumber>=1,(fr_pagenumber-1)*pageSize+','+pageSize,pageSize)}${if(fr_pagenumber>=1,(fr_pagenumber-1)*pageSize+','+pageSize,pageSize)}这段是什么意思。此处分页要是换成Oracle分页该如何设置参数?求教,感谢感谢