public static void DeleteCustomer(string customerId)
{
NorthwindEntities context = new NorthwindEntities();
Customer customer = context.Customers.Where(x => x.CustomerID == customerId).FirstOrDefault();
context.Customers.Remove(customer);
context.SaveChanges();
}
public static string InsertCustomer(string customerId, string companyName)
{
NorthwindEntities context = new NorthwindEntities();
Customer customer = new Customer
{
CustomerID = customerId,
CompanyName = companyName
};
context.Customers.Add(customer);
context.SaveChanges();
return customerId;
}
static void Main(string[] args)
{
NorthwindEntities context = new NorthwindEntities();
double income = context.FindTotalIncomeBySupplier("Leka Trading").First().Value;
Console.WriteLine(income);
income = context.FindTotalIncomeByPeriod(new DateTime(1997, 1, 1), new DateTime(1997, 6, 6)).First().Value;
Console.WriteLine(income);
income = context.FindTotalIncomeBySupplierAndPeriod("Leka Trading",
new DateTime(1997, 1, 1), new DateTime(1997, 6, 6)).First().Value;
Console.WriteLine(income);
}
public static void UpdateRegion()
{
NorthwindEntities context1 = new NorthwindEntities();
Region region1 = context1.Regions.First();
region1.RegionDescription = "Africa";
NorthwindEntities context2 = new NorthwindEntities();
Region region2 = context2.Regions.First();
region2.RegionDescription = "Europe";
context2.SaveChanges();
context1.SaveChanges();
// use transactions
}
static void FindAllCustomers(DateTime year, string country)
{
NorthwindEntities context = new NorthwindEntities();
string nativeSQLQuery =
"SELECT c.CustomerID, o.OrderDate, o.ShipCountry " +
"FROM Customers c " +
"JOIN Orders o " +
"ON c.CustomerID = o.CustomerID " +
"WHERE o.ShipCountry = {0} AND DATEPART(year, o.OrderDate) = DATEPART(year, {1})";
var customersWithOrders = context.Database.SqlQuery<CustomerAndOrder>(nativeSQLQuery, country, year);
foreach (var customer in customersWithOrders)
{
Console.WriteLine("{0} ordered on {1} from {2}", customer.CustomerID, customer.OrderDate, customer.ShipCountry);
}
}
static void InsertDuplicateOrders()
{
NorthwindEntities context = new NorthwindEntities();
Order order = new Order
{
OrderID = 1,
CustomerID = "QWE"
};
Order order2 = new Order
{
OrderID = 1,
CustomerID = "QWE"
};
context.Orders.Add(order);
context.Orders.Add(order2);
context.SaveChanges();
}
static void InsertDifferentOrders()
{
NorthwindEntities context = new NorthwindEntities();
Order order1 = new Order
{
OrderID = 2,
CustomerID = "QWE",
};
Order order2 = new Order
{
OrderID = 3,
CustomerID = "QWE"
};
context.Orders.Add(order1);
context.Orders.Add(order2);
context.SaveChanges();
}
static void FindAllCustomers(DateTime year, string country)
{
NorthwindEntities context = new NorthwindEntities();
var customersWithOrders =
from customer in context.Customers
join order in context.Orders
on customer.CustomerID equals order.CustomerID
where order.ShipCountry == country && order.OrderDate.Value.Year == year.Year
select new
{
CustomerID = customer.CustomerID,
OrderDate = order.OrderDate,
ShipCountry = order.ShipCountry
};
foreach (var customer in customersWithOrders)
{
Console.WriteLine("{0} ordered on {1} from {2}", customer.CustomerID, customer.OrderDate, customer.ShipCountry);
}
}
static void FindAllOrders(string region, DateTime? startDate, DateTime? endDate)
{
var context = new NorthwindEntities();
(context as IObjectContextAdapter)
.ObjectContext.ContextOptions.UseCSharpNullComparisonBehavior = true;
var orders =
from order in context.Orders
where order.ShipRegion == region &&
order.OrderDate.Value >= startDate && order.OrderDate.Value <= endDate
select order;
foreach (var order in orders)
{
Console.WriteLine("{0} has ordered {1} on {2} and received the order on {3} in {4}",
order.CustomerID, order.OrderID,
order.OrderDate.Value,
order.ShippedDate.Value,
order.ShipRegion == null ? "NULL" : order.ShipRegion);
}
}
public static void UpdateCustomer(string customerId, Customer newCustomer)
{
NorthwindEntities context = new NorthwindEntities();
Customer customer = context.Customers.Where(x => x.CustomerID == customerId).FirstOrDefault();
if (customer == null)
{
throw new ArgumentNullException("The customer you are looking for does not exist!");
}
customer.Address = newCustomer.Address;
customer.City = newCustomer.City;
customer.CompanyName = newCustomer.CompanyName;
customer.ContactName = newCustomer.ContactName;
customer.ContactTitle = newCustomer.ContactTitle;
customer.Country = newCustomer.Country;
customer.Fax = newCustomer.Fax;
customer.Phone = newCustomer.Phone;
customer.PostalCode = newCustomer.PostalCode;
customer.Region = newCustomer.Region;
context.SaveChanges();
}
static void Main(string[] args)
{
NorthwindEntities context = new NorthwindEntities();
context.Database.CreateIfNotExists();
}