How to have multiple projects accessing same Entity Framework project?

Question

Ok, this question has been asked many times. Just googling with the error message:

The specified named connection is either not found in the configuration,
not intended to be used with the EntityClient provider, or not valid.

I have tried all suggestions on forums, help sites et blogs... nothing works!

Situation recap

I'm splitting solution into three different projects: one for my model with EF4, one of WinForm and one ASP.NET MVC web application. I have a problem with connections string and configuration.

Is there a updated solution using VS2010/EF4/.NET Framework 4.0?

Answer 1

Not sure, but you may have to move the Entity Framework configuration sections in your EF4 project's app.config file to both your WinForm app.config and ASP.NET MVC web.config files.

Answer 2

Really, the answer is copying the <connectionStrings> section in the other project's config files like mentionned above.

<connectionStrings>
    <add name="DataEntities" connectionString="metadata=res://*/DataModel.csdl|res://*/DataModel.ssdl|res://*/DataModel.msl;provider=System.Data.SqlClient;provider connection string=&quot;Data Source=xxx;Initial Catalog=xxx;User Id=xxx;Password=xxx;MultipleActiveResultSets=True&quot;" providerName="System.Data.EntityClient" />
</connectionStrings>

So, it's the same answer as I saw before on many sites. In fact, it was working from the beginning, but I had another error ("Configuration system failed to initialize"), so I thought it was a wrong value of the connection string in the app.config. In fact, the app.config was valid, but just moving the section on bottom solved this... Bizarre?