Mapping POCO to Entity in Entity Framework

Question

I use EF for Visual Studio 2008, so I don't have POCO integration with EF.

Since we have a n-tier application, we're mapping POCO to entities constantly, entities aren't thrown to the upper layers, I do mapping with Automapper and manually also.

The big problem we have is when mapping from POCO to entities.

If I'm adding a new entity that has a relationship with existing entities (e.g. adding a new Account for an existing Client), I have the existing entity POCO, and it's needed to get the related entities (e.g. the Client) from the database, this is just something very slow.

And there is my question:

How can I create an entity, properly attached to the context and all that, from a POCO object, without making any call to the database?

Answer 1

Try the EF POCO Adapter sample: http://code.msdn.microsoft.com/EFPocoAdapter

Answer 2

Set the EntityKey instead of loading the related object from the DB (note there's a better way to do this in EF 4; this is for EF 1):

var account = new EntityAccount
              {
                  Name = pocoAccount.Name,
                  // etc.
              };
// now instead of doing account.Client = Context.Clients.Where(...
account.ClientReference.EntityKey = 
    new EntityKey("MyEntities.Clients", "Id", pocoAccount.Client.Id);

This does no DB access at all.