一个edmx文件，具有不同实现的多个数据库-支持映射详细信息

Question

I have conceptual (domain) model which is implemented in different ways in separate databases. For example, inheritance in first db is table per type, second - concrete types are tables, and third - all types properties are merged in one table. Something similar to this: Mapping objects to relational databases

Also, i have two different data access layers (for now) - first is using Entity Framework 5 - Database first approach, and second is ADO.NET dynicamic DAL where i have my DB command factory.

Client application will use these databases and client should choose on startup:

1. database to connect (connection string) and
2. data access layer (EF or classic ADO.NET) to consume data.

Depending on client's selection, system should use specified database, and selected DAL.

My questions are:

1. How can i manage Entity Framework to do a different (dynamicly) mapping details depending on connection string (First connection string - three tables, second two, third one, etc) and mapp them to the same entities?
2. Is there something else that i should pay attention to, from your experience?

Answer 1

This may be too simple. Create a common class that inherits from all three base classes. The database class in the EDMX is always a partial class so create another partial class in the same namespace which is otherwise empty. Use your partial class to generate an interface.

You can the create a domain class:

public class myCommonClass : IDatabaseClass1, DatabaseClass2, DatabaseClass3

and then work with myCommonClass in your application. You can then use Automapper to go between the database classes and the domain classes. Automapper lives here .

It's a Sunday morning so reply may be a little sketchy, and you're probably doing a lot of this anyway but ...