恢复数据库：
  关键字：Alter Database 被恢复的数据库名 Set Offline with Rollback immediate;
            restore database 被恢复的数据库名 from disk = '备份文件路径';
            Alter Database 被恢复的数据库名 Set OnLine With rollback Immediate;
注意,备分时没有问题,但恢复时要注意先停sqlserver
/
    string sql = "Alter Database db Set Offline with Rollback immediate;"; //db 是要备份的数据库名
    sql +=  "restore database db from disk = '" ;
    sql += Server.MapPath("").ToString() +"\\";
    sql += bakname + "'";  //bakname 是备份文件名
    sql += "Alter Database db Set OnLine With rollback Immediate;";
    try
    {
     连接 master 数据库 ;
     执行 sql  语句;
     Response.Write("<script language=javascript>alert('数据恢复成功！');</script>");
    }
    catch(Exception ex)
    {
     Response.Write("<script language=javascript>alert('数据恢复失败！');</script>");
     this.Label2.Text = ex.ToString();
    }

备份数据库：

关键字：backup database 被备份的数据库名 to disk ='备份文件路径';
//     
 string sql = "backup database db to disk = '" + Server.MapPath("").ToString() +"\\"
    + bakname  //备份文件名 
    + System.DateTime.Now.DayOfYear.ToString()
    + System.DateTime.Now.Millisecond.ToString() + ".bak'";
   Database data = new Database();
   data.oper_data(sql);
   Response.Write("<script language=javascript>alert('备份成功！');location='restore.aspx'</script>");