LINQ to SQL - Customising Insert, Update, and Delete Operations

The DataContext "Extensibility Method Definitions" can be used to modify the default behaviour of the Insert Update Delete partial classes:

namespace LinqToSql.OverrideDatabaseStatements
{
    public partial class NorthwindDataContext
    {
        partial void InsertCustomer(Customer instance)
        {
            string result = "I'm here InsertCustomer";
            this.ExecuteDynamicInsert(instance);
        }
        partial void UpdateCustomer(Customer instance)
        {
            string result = "I'm here UpdateCustomer";
            this.ExecuteDynamicUpdate(instance);
        }
        partial void DeleteCustomer(Customer instance)
        {
            string result = "I'm here DeleteCustomer";
            this.ExecuteDynamicDelete(instance);
        }
    }
}

This has proved useful to automatically-populate audit details e.g. DateAdded, AddedBy etc.

Thanks to Pedro Rainho's post for this!