I've been having a brief look at NHibernate and Linq2Sql. I'm also intending to have a peek at Entity Framework. The question that gets raised, when I talk of these ORM's is "They can't scale", so can they? From Google I get the impression they're able to scale well, but ultimately I suppose there must be a price to pay, Is it worth pay...
Hi, I am a newbie in the DDD+TDD World. But I have been in programming for almost 9 years. Can someone please explain me the benefits of persistance ignornace ? Typical nHibernate application just pushes the dependency between class and database to mapping files. If I change Class files or Database, I have to change the mapping files....
I have an existing domain layer. I want to develop the persistence layer using Linq to SQL. I am currently using an external map file. I am trying to use lazy loading for my child collections but am unsuccessful. Is there a way to implement lazy loading using Linq to SQL but without using EntitySet or EntityRef. ...
I've implemented a repository pattern with persistence ignorance. The repository implementation only interacts with my entity objects, IUnitOfWork and ITable<T> interfaces. The intention is that the IUnitOfWork isn't reused but represents a single transaction. So far, I've implemented in-memory as well as Linq-to-Sql versions of the IUni...
I'm trying to write my Domain Model as persistence-ignorant as possible. The only thing I'm doing right now is marking every property and method virtual, as NHibernate requires that for lazy-loading. In my domain model assembly I define some repository interfaces: public interface IRepository<TEntity> where TEntity : EntityBase { T...
Persistence ignorance is typically defined as the ability to persist & retrieve standard .NET objects (or POCOs if you really insist on giving them a name). And a seemingly well accepted definition of a standard .NET object is: "...ordinary classes where you focus on the business problem at hand without adding stuff for infrastructur...
Hello, Let's consider the typical Order and OrderItem example. Assuming that OrderItem is part of the Order Aggregate, it an only be added via Order. So, to add a new OrderItem to an Order, we have to load the entire Aggregate via Repository, add a new item to the Order object and persist the entire Aggregate again. This seems to hav...
I'm trying EF 4 with POCO's on a small project for the first time. In my Repository implementation, I want to provide a method AddOrUpdate that will add a passed-in POCO to the repository if it's new, else do nothing (as the updated POCO will be saved when SaveChanges is called). My first thought was to do this: public void AddOrUpdat...