I am trying to use Entity Framework 5 (code-first) for an ASP.NET Web Forms application, I have previously had a basic implementation running using the MySQL connection and
Questions is old, but may be this will be helpful for somebody.
I've got the same issue with transition from Oracle to MS SQL Server. Eventually, it appeared that code migrations were the root cause of the issue. You cannot just leave them as is after switching to another database provider. So, you must REGENERATE migrations for your new database provider.