Cannot insert the value NULL into column 'Discriminator' AspNetUsers Table

问题

After a code first migration, adding a user using the register fails with:

Cannot insert the value NULL into column 'Discriminator', table 'aspnet-BSF2013-20130918101120.dbo.AspNetUsers'; column does not allow nulls.

The create user code is the default code generated by the Project Template (Vs2013, MVC project with EF5)

Before a successful migration, the Registration code worked, so I'm guessing that membership has been altered by EF.

来源：https://stackoverflow.com/questions/18938514/cannot-insert-the-value-null-into-column-discriminator-aspnetusers-table