单表查询 (LINQ to DataSet)

// Fill the DataSet.DataSet ds = new DataSet();ds.Locale = CultureInfo.InvariantCulture;FillDataSet(ds);DataTable orders = ds.Tables["SalesOrderHeader"];var query =    from order in orders.AsEnumerable()    where order.Field<bool>("OnlineOrderFlag") == true    select new    {        SalesOrderID = order.Field<int>("SalesOrderID"),        OrderDate = order.Field<DateTime>("OrderDate"),        SalesOrderNumber = order.Field<string>("SalesOrderNumber")    };foreach (var onlineOrder in query){    Console.WriteLine("Order ID: {0} Order date: {1:d} Order number: {2}",        onlineOrder.SalesOrderID,        onlineOrder.OrderDate,        onlineOrder.SalesOrderNumber);}