EF生成的表被更改后的错误

1.在Global.ascs设置

public class MvcApplication : System.Web.HttpApplication
{
protected void Application_Start()
{
Database.SetInitializer<userMSMVC.Models.userMSMVCContext>(null);
AreaRegistration.RegisterAllAreas();
RouteConfig.RegisterRoutes(RouteTable.Routes);
}
}