How to: Manage the Connection in a Long-Running Object Context

// Define the order ID for the order we want.
int orderId = 43680;

// Create a long-running context.
AdventureWorksEntities context =
    new AdventureWorksEntities();

try
{
    if (context.Connection.State != ConnectionState.Open)
    {
        // Explicitly open the connection.
        context.Connection.Open();
    }

    // Execute a query to return an order.
    SalesOrderHeader order =
        context.SalesOrderHeaders.Where(
        "it.SalesOrderID = @orderId", new ObjectParameter("orderId", orderId))
        .Execute(MergeOption.AppendOnly).First();

    // Change the status of an existing order.
    order.Status = 1;

    // You do not have to call the Load method to load the details for the order,
    // because  lazy loading is set to true 
    // by the constructor of the AdventureWorksEntities object. 
    // With  lazy loading set to true the related objects are loaded when
    // you access the navigation property. In this case SalesOrderDetails.

    // Delete the first item in the order.
    context.DeleteObject(order.SalesOrderDetails.First());

    // Save changes.
    if (0 < context.SaveChanges())
    {
        Console.WriteLine("Changes saved.");
    }

    // Create a new SalesOrderDetail object.
    // You can use the static CreateObjectName method (the Entity Framework
    // adds this method to the generated entity types) instead of the new operator:
    // SalesOrderDetail.CreateSalesOrderDetail(1, 0, 2, 750, 1, (decimal)2171.2942, 0, 0,
    //                                         Guid.NewGuid(), DateTime.Today));
    SalesOrderDetail detail = new SalesOrderDetail
    {
        SalesOrderID = 0,
        SalesOrderDetailID = 0,
        OrderQty = 2,
        ProductID = 750,
        SpecialOfferID = 1,
        UnitPrice = (decimal)2171.2942,
        UnitPriceDiscount = 0,
        LineTotal = 0,
        rowguid = Guid.NewGuid(),
        ModifiedDate = DateTime.Now
    };

    order.SalesOrderDetails.Add(detail);


    // Save changes again.
    if (0 < context.SaveChanges())
    {
        Console.WriteLine("Changes saved.");
    }
}
catch (InvalidOperationException ex)
{
    Console.WriteLine(ex.ToString());
}
finally
{
    // Explicitly dispose of the context, 
    // which closes the connection. 
    context.Dispose();
}