public static void Delete(string id)
{
using (NORTHWNDEntities db = new NORTHWNDEntities())
{
var customer = db.Customers.Where(x => x.CustomerID == id).FirstOrDefault();
db.Customers.Remove(customer);
db.SaveChanges();
}
}
public static void Modify(string id, string newContactName)
{
using (NORTHWNDEntities db = new NORTHWNDEntities())
{
var customer = db.Customers.Where(x => x.CustomerID == id).FirstOrDefault();
customer.ContactName = newContactName;
db.SaveChanges();
}
}
public static void Insert(string id, string name)
{
Customer newCustomer = new Customer()
{
CompanyName = name,
CustomerID = id
};
using (NORTHWNDEntities db = new NORTHWNDEntities())
{
bool isInDB = IsInDataBase(db, id);
if (!isInDB)
{
db.Customers.Add(newCustomer);
db.SaveChanges();
Console.WriteLine("Added Successful.");
}
else
{
throw new ArgumentException("Such customer already exists");
}
}
}
// Task 9
private static void CreateNewOrder(Order order)
{
using (TransactionScope scope = new TransactionScope())
{
NORTHWNDEntities db = new NORTHWNDEntities();
var customer = db.Customers.First(c => c.CustomerID == order.CustomerID);
if (customer != null)
{
order.ShipAddress = customer.Address;
order.ShipCity = customer.City;
order.ShipPostalCode = customer.PostalCode;
order.ShipCountry = customer.Country;
}
db.Orders.Add(order);
db.SaveChanges();
scope.Complete();
}
}
// Task 7
private static void ConcurrentChages()
{
using (TransactionScope scope = new TransactionScope())
//using (TransactionScope scope = new TransactionScope(TransactionScopeOption.Required, new
// TransactionOptions { IsolationLevel= IsolationLevel.Snapshot }))
{
NORTHWNDEntities db = new NORTHWNDEntities();
Product product = db.Products.First(p => p.ProductID == 1);
product.ProductName = "Test 001";
db.SaveChanges();
NORTHWNDEntities db2 = new NORTHWNDEntities();
Product product2 = db2.Products.First(p => p.ProductID == 1);
product2.ProductName = "Test 002";
try
{
int result = db2.SaveChanges();
Console.WriteLine(result.ToString() +
" products changed");
}
catch (OptimisticConcurrencyException)
{
db2.Entry(product2).Reload();
//db2.Refresh(RefreshMode.ClientWins, db2.Products);
db2.SaveChanges();
}
scope.Complete();
}
}