private static void SelectManyCompoundFrom2()
{
Console.WriteLine("This sample uses a compound from clause to select all orders where the order total is less than 500.00.");
List <Customer> customers = factory.GetCustomerList();
var orders = from customer in customers
from order in customer.Orders
where order.Total < 500.00M
select new { customer.CustomerID, order.OrderID, order.Total };
foreach (var order in orders)
{
Console.WriteLine("Customer ID = {0}, Order Id = {1}, Total = {2}", order.CustomerID, order.OrderID, order.Total);
}
}
private static void TakeNested()
{
Console.WriteLine("This sample uses Take to get the first 3 orders from customers in Washington.");
List <Customer> customers = factory.GetCustomerList();
var first3WAOrders = from customer in customers
where customer.Region == "WA"
from order in customer.Orders.Take(3)
select new { customer.CustomerID, order.OrderID, order.OrderDate };
Console.WriteLine("First 3 orders in WA:");
foreach (var order in first3WAOrders)
{
Console.WriteLine("Customer ID = {0}, Order Id = {1}, Total = {2}", order.CustomerID, order.OrderID, order.OrderDate);
}
}
private static void UnionII()
{
Console.WriteLine("This sample uses Union to create one sequence that contains the unique first letter from both product and customer names.");
List <Product> products = factory.GetProductList();
List <Customer> customers = factory.GetCustomerList();
var productFirstChars = from product in products
select product.ProductName[0];
var customerFirstChars = from customer in customers
select customer.CompanyName[0];
var uniqueFirstChars = productFirstChars.Union(customerFirstChars);
Console.WriteLine("Unique first letters from Product names and Customer names:");
foreach (var ch in uniqueFirstChars)
{
Console.WriteLine(ch);
}
}
private static void GroupByNested()
{
Console.WriteLine("This sample uses group by to partition a list of each customer's orders, first by year, and then by month.");
List <Customer> customers = factory.GetCustomerList();
var customerOrderGroups = from customer in customers
select
new
{
customer.CompanyName,
YearGroups = from order in customer.Orders
group order by order.OrderDate.Year into yearGroup
select
new
{
Year = yearGroup.Key,
MonthGroups = from order in yearGroup
group order by order.OrderDate.Month into monthGroup
select
new
{
Month = monthGroup.Key,
Orders = monthGroup
}
}
};
foreach (var item in customerOrderGroups)
{
Console.WriteLine("Company Name = {0}, Year Groups ", item.CompanyName);
foreach (var yearGroup in item.YearGroups)
{
Console.WriteLine("Year : {0}", yearGroup.Year);
foreach (var monthGroup in yearGroup.MonthGroups)
{
Console.WriteLine("Month : {0}", monthGroup.Month);
foreach (var monthOrders in monthGroup.Orders)
{
Console.WriteLine("Order ID : = {0}, Total = {1} ", monthOrders.OrderID, monthOrders.Total);
}
}
}
}
}
private static void CountNested()
{
Console.WriteLine("This sample uses Count to return a list of customers and how many orders each has.");
List <Customer> customers = factory.GetCustomerList();
var orderCounts = from customer in customers
select new
{
Customer = customer.CustomerID,
OrderCount = customer.Orders.Count()
};
foreach (var item in orderCounts)
{
Console.WriteLine("Customer ID = {0}, Order Count = {1}", item.Customer, item.OrderCount);
}
}
public static void WhereDrillDown()
{
Console.WriteLine("This sample uses where to find all customers in Washington and then uses the resulting sequence to drill down into their orders.");
List <Customer> customers = factory.GetCustomerList();
var waCustomers = from customer in customers
where customer.Region == "WA"
select customer;
Console.WriteLine("Customers from Washington and their orders:");
foreach (Customer customer in waCustomers)
{
Console.WriteLine("Customer {0}: {1}", customer.CustomerID, customer.CompanyName);
foreach (Order order in customer.Orders)
{
Console.WriteLine(" Order {0}: {1}", order.OrderID, order.OrderDate);
}
}
}
private static void ConcatII()
{
Console.WriteLine("This sample uses Concat to create one sequence that contains the names of all customers and products, including any duplicates.");
List <Customer> customers = factory.GetCustomerList();
List <Product> products = factory.GetProductList();
var customerNames = from customer in customers
select customer.CompanyName;
var productNames = from product in products
select product.ProductName;
var allNames = customerNames.Concat(productNames);
Console.WriteLine("Customer and product names:");
foreach (var n in allNames)
{
Console.WriteLine(n);
}
}
