OracleCore3EF64Sample sample aplication targeting netcoreapp3.1 framework (SDK 3.1.200) and using this NuGet packages:
EntityFramework version 6.4.0 (netstandard2.1) - Entity Framework 6.4 for .NET Core 3.x
Oracle.ManagedDataAccess.Core version 2.19.60 - Official Oracle ODP.NET, Managed Driver for EF Core 2.x, certified for .NET Core 3.x.
Oracle.ManagedDataAccess.EntityFramework.Core (netstandard2.1) - My NOT OFFICIAL NuGet (for my private use).
It's recompilation of offical Oracle.ManagedDataAccess.EntityFramework version 19.6.0 (net45) NuGet and Oracle.ManagedDataAccess.EntityFramework.dll assembly (v. 6.122.19.1) using Oracle.ManagedDataAccess.Core NuGet instead of Oracle.ManagedDataAccess NuGet.
This NuGet is not included in this repo (due to license), but it is in my private repo (ask me to add access).
To compile this sample you must add Oracle.ManagedDataAccess.EntityFramework.Core.19.6.0.nupkg to .\Packages folder and edit connection string in Program.cs source file.