MySQLNumberTypeMapping' does not support value conversions

The MySQL data provider does not implement the value conversion feature. You are getting this exception because you are using enums as data types which must be converted by the MySQL data provider which does not implement this feature and therefore throws a NotImplementedException.

This bug has already been reported: https://bugs.mysql.com/bug.php?id=89855

There is also an open github issue: https://github.com/aspnet/EntityFrameworkCore/issues/11078

In short, MySQL.Data.EntityFrameworkCore, running on .Net Core 2.0, does not function correctly while using Microsoft.EntityFrameworkCore.Relational 2.1.0-preview1-final, despite claims that 2.0 conformant providers should work on it.

In order to continue development I found a suitable solution was to

Install-Package Pomelo.EntityFrameworkCore.Mysql -version 2.1.0-rc1-final

using nuget console and modify any reference of options.UseMySQL to options.UseMySql.

This allowed me to continue with dotnet 2.1 and utilize a mysql database.

Hope this helps!