Disconnected Behavior of Entity Framework when Updating Object Graph

Question

I\'m currently working with a project that use following technologies.

1. ASP.net MVC - presentation Layer
2. Data Service Layer - (WCF)
3. Data Transfer

Answer 1

Julie Lerman explains this very well in some video's

Answer 2

There are not many option to solve it. EF doesn't have any direct support for updating disconnected object graphs. You must code your update logic and there are generally two ways how to do it:

• When you receive updated user from the service request you will call database and fetch current database state = user with all affected relations. You will use database version and updated version to build valid change set so at the end EF will update, insert and delete only data which have really changed.
• You will modify your DTOs to transport state as well and your client will be responsible for setting the type of modification he did on the DTO. You will use this information to correctly configure ChangeTracker for every received entity.

Answer 3

Is your issue now that you use EF and it makes lots of calls for updates? I don't see a way around that here as your phone numbers and emails are separate tables. You could create a flattened entity for the user that contains ex five of each and map to a proc for your insert. It would reduce calls but not the cleanest IMHO. If you are processing many users at once then maybe breakup the UOW to act per user only so you have shorter transactions. Is there currently a performance issue or just a future concern? –

Without flattening you are in no different of a scenario than without using EF. I don't understand why thought because you are using DDD you can't introduce entities specific to data mappings.Your Entities can still be used, you just in addition have a new entity with mappings. In fact you can do this without entities in your repository later (repository queries changed objects, flattens and sends to data access layer to call proc)