Using Entity Framework with Sql Server Compact Edition without App.Config additions

Question

I am developing a plug-in for Rhinoceros 6 and making editions to App.Config file of Rhinoceros seems impossible so far. App.Config of the plug-in project has no effect on App.Config of Rhinoceros.

Below error message appears because I couldn't add providers and parameters to App.Config's entityFramework section.

Unable to determine the provider name for provider factory of type 'System.Data.SqlServerCe.SqlCeProviderFactory'. Make sure that the ADO.NET provider is installed or registered in the application config.

I installed EntityFramework.SqlServer.Compact and Microsoft.SqlServer.Compact with NuGet and checked for references, all seems good.

Below is my code-first dbcontext class :

        public class ModelLocalClipper : DbContext
    { 
        public ModelLocalClipper()
            : base(new SqlCeConnection("Data Source="+ Environment.GetFolderPath(Environment.SpecialFolder.Desktop)+"\\MyDatabase.sdf;Persist Security Info=False;"),
  contextOwnsConnection: true)
        {
            Database.SetInitializer<ModelLocalClipper>(new CreateDatabaseIfNotExists<ModelLocalClipper>());
        }
        
        public DbSet<Scene> Scenes { get; set; }
        public DbSet<LocalProject> LocalProjects { get; set; }
    }

    public class Scene
    {
        public int SceneId { get; set; }
        public string Name { get; set; }

        public int LocalProjectId { get; set; }

        [ForeignKey("LocalProjectId")]
        public virtual LocalProject LocalProject { get; set; }
    }

    public class LocalProject
    {
        public int LocalProjectId { get; set; }
        public string Name { get; set; }

        public virtual ICollection<Scene> Scenes { get; set; }
    }

After searching a while I found this solution and transformed that to use for SqlCe as below but it didn't help either

public class SqlCeProviderInvariantName : IProviderInvariantName
        {
            public static readonly SqlCeProviderInvariantName Instance = new SqlCeProviderInvariantName();
            private SqlCeProviderInvariantName() { }
            public const string ProviderName = "System.Data.SqlServerCe.4.0";
            public string Name { get { return ProviderName; } }
        }

    class SqlCeDbProviderFactoryResolver : IDbProviderFactoryResolver
    {
        public static readonly SqlCeDbProviderFactoryResolver Instance = new SqlCeDbProviderFactoryResolver();
        private SqlCeDbProviderFactoryResolver() { }
        public DbProviderFactory ResolveProviderFactory(DbConnection connection)
        {
            if (connection is SqlCeConnection) return SqlCeProviderFactory.Instance;
            if (connection is EntityConnection) return EntityProviderFactory.Instance;
            return null;
        }
    }

    class SqlCeDbDependencyResolver : IDbDependencyResolver
    {
        public object GetService(Type type, object key)
        {
            if (type == typeof(IProviderInvariantName)) return SqlCeProviderInvariantName.Instance;
            if (type == typeof(DbProviderFactory)) return SqlCeProviderFactory.Instance;
            if (type == typeof(IDbProviderFactoryResolver)) return SqlCeDbProviderFactoryResolver.Instance;
            return SqlCeProviderServices.Instance.GetService(type);
        }

        public IEnumerable<object> GetServices(Type type, object key)
        {
            var service = GetService(type, key);
            if (service != null) yield return service;
        }
    }

    class SqlCeDbConfiguration : DbConfiguration
    {
        public SqlCeDbConfiguration()
        {
            AddDependencyResolver(new SqlCeDbDependencyResolver());
        }
    }

Versions : -RhinoCommon 6.30.20288.16410 -.NET Framework 4.8 -EntityFramework 6.4.4 -SqlServerCe.4.0

With directives of ErikEJ, it worked! For those who want to look into the code here is the repo: https://github.com/Tahirhan/RhinoPluginSqlCECodeFirst

Thanks!

Answer 1

Try this (much simpler) approach, I was able to make that work with a Console app:

public class SqlCeDbConfiguration : DbConfiguration 
{
    public SqlCeDbConfiguration()
    {
        SetProviderServices(
            SqlCeProviderServices.ProviderInvariantName,
            SqlCeProviderServices.Instance);

        SetDefaultConnectionFactory(
            new SqlCeConnectionFactory(SqlCeProviderServices.ProviderInvariantName));
    }
}

And then:

[DbConfigurationType(typeof(SqlCeDbConfiguration))]
public class ModelSqlCECodeFirst : DbContext

Answer 2

As this answer suggested, For SQLite scenario try this DbConfiguration and don't forget to remove "|DataDirectory|" part from connection string

public class SQLiteConfiguration : DbConfiguration
{
    public SQLiteConfiguration()
    {
        SetProviderFactory("System.Data.SQLite", SQLiteFactory.Instance);
        SetProviderFactory("System.Data.SQLite.EF6", SQLiteProviderFactory.Instance);
        SetProviderServices("System.Data.SQLite", (DbProviderServices)SQLiteProviderFactory.Instance.GetService(typeof(DbProviderServices)));
    }
}