现在将EF1.1升级到EF2.0后，我无法进行迁移。从EF Core 1.1升级到2.0预览
Error: Startup project 'QilinSystem.Store.Data.csproj' targets framework '.NETStandard'. This framework is not intended for execution and may fail to resolve runtime dependencies. If so, specify a different project using the --s tartup-project option and try again.
如何解决这个问题？
EF Core 2.0 Preview 1需要Visual Studio 15.3 Preview，所以你必须安装它。
Announcing EF Core 2.0 Preview 1：
Accessing .NET Core tooling in Visual Studio requires Visual Studio 2017 15.3 Preview, Visual Studio for Mac or Visual Studio Code. More information about this and download links can be found in the .NET Core 2.0 Preview 1 announcement.
Preview installs next to your stable Visual Studio IDE, allowing you to use either independently.