Question

I am porting an application’s persistent storage mechanics from SQL Compact to Oracle.

Current Implementation

The application implements Entity Framework 5 (EF), but it is pretty tightly coupled: (a) there is no service layer between EF and the Controllers, and (b) there is no IRepository-style abstraction between EF and SQL Compact.

The C# models are simple POCOs but are rich with data annotations, and is used “code-first” style to generate DB schema.

Problem (Oracle)

I must use Oracle’s standard ODP.Net provider. The provider supports EF, but does not support “code-first” methodology, only “model first”.

Intended Solution

I am trying to find a way to preserve the EF implementation tightly coupled to the controllers, and the richness of the model class annotations, while using them to build the “model-first” style EDMX file that Oracle can swallow. Essentially, I am looking for a way to mimic “code-first”.

I was hoping it would be as simple as dragging my C# objects onto the EDMX file but it seems like there’s much more going on.

Question

How can I build an .EDMX file using C# models that already exist? If it is not possible, what is the next best solution for accomplishing this goal?

Note: Please do not recommend paid-for third party products. The solution must be doable with Visual Studio, C#, an open source library, or some combination.

Answer 1

If you have DbContext you can use ‘EdmxWriter.WriteEdmx()’ to write your model as the edmx file that you should be able to open with the designer.