static void DeleteEntry(string id)
{
var database = new NorthwindEntities();
using (database)
{
if (EntryExists(database, id))
{
var itemToDelete = database.Customers.Where(c => c.CustomerID == id).First();
database.Customers.Remove(itemToDelete);
database.SaveChanges();
Console.WriteLine("Entry successfully deleted.");
}
else
{
Console.WriteLine("Item with the id \"{0}\" does not exist in the database.", id);
}
}
}
static void AddEntry(string id, string name)
{
var database = new NorthwindEntities();
using (database)
{
if (EntryExists(database, id))
{
Console.WriteLine("There is already an entry with the same ID");
}
else
{
var newCustomer = new Customer()
{
CustomerID = id,
CompanyName = name
};
database.Customers.Add(newCustomer);
database.SaveChanges();
Console.WriteLine("Entry successfully added.");
}
}
}
static void ModifyEntry(string id, string newName)
{
var database = new NorthwindEntities();
using (database)
{
if (EntryExists(database, id))
{
var itemToDelete = database.Customers.Where(c => c.CustomerID == id).First();
itemToDelete.CompanyName = newName;
database.SaveChanges();
Console.WriteLine("Entry successfully modified.");
}
else
{
Console.WriteLine("Item with the id \"{0}\" does not exist in the database.", id);
}
}
}
private static void FindSalesByRegionAndDate(string region, DateTime start, DateTime end)
{
var database = new NorthwindEntities();
using (database)
{
var sales = database.Orders.Where(
o => o.ShipRegion == region &&
o.OrderDate > start &&
o.OrderDate < end
).Select(
o => new
{
ShipName = o.ShipName,
OrderDate = o.OrderDate
});
foreach (var item in sales)
{
Console.WriteLine("Ship Name: {0}", item.ShipName);
Console.WriteLine("Order Date: {0}", item.OrderDate);
Console.WriteLine("--------------------");
}
}
}
private static void ShipmentsToCanada()
{
var database = new NorthwindEntities();
using (database)
{
var groupedCustomersAndOrders = database.Customers.Join(
database.Orders,
c => c.CustomerID,
d => d.CustomerID,
(c, d) => new
{
Name = c.CompanyName,
OrderDate = d.OrderDate,
ShipmentCountry = d.ShipCountry
});
var items = groupedCustomersAndOrders
.Where(i => i.OrderDate.Value.Year == 1997)
.Where(i => i.ShipmentCountry == "Canada");
foreach (var item in items)
{
Console.WriteLine(item.Name);
}
}
}
static bool EntryExists(NorthwindEntities database, string id)
{
return database.Customers.Where(c => c.CustomerID == id).Any();
}
