Can't have the same table names in different entity framework models?

Question

My application uses two different SQL 2008 databases. The databases have a few tables with the same name, ie. Users. I would like to use EF4 for both these data

Answer 1

To use the "default convention based mapping" the following 2 approaches will work:

1) The collision is caused by the connection string using a wild card:

    metadata=res://*/Repositories.EntityFramework.Model.csdl|res://*/Repositories.EntityFramework.Model.ssdl|res://*/Repositories.EntityFramework.Model.msl;

Since * does not work your project you can define multiple connection strings to hard code the assembly containing the edmx.

2) create a helper

    public static EntityConnection GetEfConnectionString(this string sqlConnectionString)
    {
        var cs = string.Format(@"metadata=res://{0}/Repositories.EntityFramework.Model.csdl|res://{0}/Repositories.EntityFramework.Model.ssdl|res://{0}/Repositories.EntityFramework.Model.msl;provider=System.Data.SqlClient;provider connection string=""" + sqlConnectionString + @"""",
            Assembly.GetCallingAssembly().FullName
        );

        return new EntityConnection(cs);
    }

Update 2017:

    public static string GetEfConnectionString(this string sqlConnectionString, Type type)
    {
        string cs =
            string.Format(
                @"metadata=res://{0}/Models.Model.csdl|res://{0}/Models.Model.ssdl|res://{0}/Models.Model.msl;provider=System.Data.SqlClient;provider connection string=""" +
                sqlConnectionString + @"""",
                type.Assembly.FullName
                );
        return cs;
    }


    // usage: don't "new" EntityConnection.  See 2012 comment.
    string connString = ConfigurationManager.ConnectionStrings["sqlConnection"].ConnectionString.GetEfConnectionString();
    using(var entities = new XyzEntities(connString))

Answer 2

For DB first approach, Luckily there are couple of workarounds which are pretty straightforward:

1. Make sure that that both contexts don't share tables with the same name - not the most practical approach.
2. Restructure the solution by isolating the database contexts within their own assemblies.

For more detail, please refer this link

Explained very clearly.

Answer 3

I had the same problem, but my solution was to delete the DLL of the MODEL\edmx from the project, because it was copied from a different project, and then rebuild it. Solved everything!

Answer 4

The error means, what he says: You can't use the default convention based mapping in your scenario. Use custom database mapping instead. Scott Guthrie has a detailed blog item about this.

Answer 5

Another reason for that error is what happened to me: My project was copied from somewhere else and I renamed the project, so after compiling there were 2 DLL's in my bin folder. The one from the previous project and a brand new one, named according to the new project. Once I deleted the previous/old DLL the namespace ambiguity disappeared and the error went away.