public static void DeleteCustomer(string customerId)
{
NorthwindEntities northwindEntities = new NorthwindEntities();
Customer customerToDelete = northwindEntities.Customers.FirstOrDefault(c => c.CustomerID == customerId);
if (customerToDelete == null)
{
throw new System.Data.EntityException("There is no such customer.");
}
northwindEntities.Customers.Remove(customerToDelete);
northwindEntities.SaveChanges();
}
public static void Main()
{
NorthwindEntities firstContext = new NorthwindEntities();
NorthwindEntities secondContext = new NorthwindEntities();
ModifyCustomer(firstContext, "ALFKI", city: "Moscow");
ModifyCustomer(secondContext, "ALFKI", city: "London");
// Since database is not locked, the last modification will be the one to remain. According to MSDN:
// http://msdn.microsoft.com/en-us/library/bb739065.aspx SaveChanges(boolean) is obsolete and should
// not be used.
firstContext.SaveChanges();
secondContext.SaveChanges();
firstContext.Dispose();
secondContext.Dispose();
}
public static void InsertCustomer(string customerId, string companyName, string contactName = null, string address = null,
string city = null, string region = null, string postalCode = null, string country = null, string phone = null,
string fax = null)
{
NorthwindEntities northwindEntities = new NorthwindEntities();
int numberOfCustomersBefore =
(from customer in northwindEntities.Customers
select customer).Count();
Customer customerToInsert = new Customer
{
CustomerID = customerId,
CompanyName = companyName,
Address = address,
City = city,
PostalCode = postalCode,
Region = region,
Country = country,
Phone = phone,
Fax = fax
};
northwindEntities.Customers.Add(customerToInsert);
northwindEntities.SaveChanges();
int numberOfCustomersAfter =
(from customer in northwindEntities.Customers
select customer).Count();
if (numberOfCustomersAfter - numberOfCustomersBefore == 1)
{
Console.WriteLine("Customer added successfully.");
}
else
{
throw new System.Data.EntityException("Incorrect insertion result.");
}
}
public static void ModifyCustomer(string customerId, string companyName = null, string contactName = null, string address = null,
string city = null, string region = null, string postalCode = null, string country = null, string phone = null,
string fax = null)
{
NorthwindEntities northwindEntities = new NorthwindEntities();
Customer customerToModify = northwindEntities.Customers.FirstOrDefault(c => c.CustomerID == customerId);
if (customerToModify == null)
{
throw new System.Data.EntityException("No such customer exists.");
}
customerToModify.CompanyName = string.IsNullOrEmpty(companyName) ? customerToModify.CompanyName : companyName;
customerToModify.ContactName = string.IsNullOrEmpty(contactName) ? customerToModify.ContactName : contactName;
customerToModify.Address = string.IsNullOrEmpty(address) ? customerToModify.Address : address;
customerToModify.City = string.IsNullOrEmpty(city) ? customerToModify.City : city;
customerToModify.Region = string.IsNullOrEmpty(region) ? customerToModify.Region : region;
customerToModify.PostalCode = string.IsNullOrEmpty(postalCode) ? customerToModify.PostalCode : postalCode;
customerToModify.Country = string.IsNullOrEmpty(country) ? customerToModify.Country : country;
customerToModify.Phone = string.IsNullOrEmpty(phone) ? customerToModify.Phone : phone;
customerToModify.Fax = string.IsNullOrEmpty(fax) ? customerToModify.Fax : fax;
northwindEntities.SaveChanges();
}
public static void InsertOrder(int shipperId, string customerId, int employeeId, string destionation)
{
using (NorthwindEntities northwindEntities = new NorthwindEntities())
{
try
{
using (TransactionScope scope = new TransactionScope())
{
Order orderToInsert = new Order
{
CustomerID = customerId,
EmployeeID = employeeId,
OrderDate = DateTime.Now,
RequiredDate = DateTime.Now.Add(new TimeSpan(100, 0, 0, 0)),
ShipVia = shipperId,
Freight = 3000000,
ShipCountry = destionation,
Customer = northwindEntities.Customers.FirstOrDefault(c => c.CustomerID == customerId),
Employee = northwindEntities.Employees.FirstOrDefault(e => e.EmployeeID == employeeId),
Shipper = northwindEntities.Shippers.FirstOrDefault(s => s.ShipperID == shipperId),
Order_Details = new HashSet<Order_Detail>()
};
orderToInsert.Order_Details.Add(new Order_Detail
{
ProductID = 2,
Quantity = 34,
Discount = 1,
Order = orderToInsert
});
orderToInsert.Order_Details.Add(new Order_Detail
{
ProductID = 3,
Quantity = 70,
Discount = 1,
Order = orderToInsert
});
orderToInsert.Order_Details.Add(new Order_Detail
{
ProductID = 4,
Quantity = 110,
Discount = 1,
Order = orderToInsert
});
northwindEntities.Orders.Add(orderToInsert);
northwindEntities.SaveChanges();
scope.Complete();
//This ensures that the transaction has been completed.
int orderId = orderToInsert.OrderID;
Console.WriteLine(orderId);
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
}
}