Using the Entity Framework in N-Tier Applications - Entity Framework 6 Recipes - page 330

var order = new Order { Product = "Camping Tent",
Quantity = 3, Status = "Received" };
context.Orders.Add(order);
context.SaveChanges();
return order;
}
}
public void UpdateOrderWithoutRetrieving(Order order)
{
using (var context = new EFRecipesEntities())
{
try
{
context.Orders.Attach(order);
if (order.Status == "Received")
{
context.Entry(order).Property(x => x.Quantity).IsModified = true;
context.SaveChanges();
}
}
catch (OptimisticConcurrencyException ex)
{
// Handle OptimisticConcurrencyException
}
}
}
public void UpdateOrderByRetrieving(Order order)
{
using (var context = new EFRecipesEntities())
{
// fetch current entity from database
var dbOrder = context.Orders
.Single(o => o.OrderId == order.OrderId);
if (dbOrder != null &&
// execute concurrency check
StructuralComparisons.StructuralEqualityComparer.Equals(order.TimeStamp, dbOrder.TimeStamp))
{
dbOrder.Quantity = order.Quantity;
context.SaveChanges();
}
else
{
// Add code to handle concurrency issue
}
}
}
}