1、分页查询
int PageRow = Request["size"];   //每页行数
int PageCur = Request["page"];   //当前页
int na = (PageCur - 1) * PageRow + 1;   //分页sql起讫行号
int nb = PageCur * PageRow;   

//通用分页语句sql2005以上支持

string sql = "select * from (select row_number() over(order by ID desc) as rnum,t.* from XNews as t "
 + " where t.ClassID=@ClassID and t.Flag=1"  // and t.Title1 like @key 模糊查询
 + ") t  where rnum between " + na + " and " + nb + "";