Scaffold migration with context key change

Question

I have restructured my project which led to a change of namespace name of the database context and associated Code First configuration. At that point, I've had one scaffolded migration, "InitialCreate" and thus my database's __MigrationHistory table contained a single row with some MigrationId and a ContextKey containing the namespace name and class name of the Configuration class.

After I've moved things around, executing Get-Migrations returned no results, after changing the ContextKey as per my colleague's advice, the "InitialCreate" migration was correctly enumerated.

What steps should I have taken during the changes so the continuity of my migrations wasn't broken, preventing the need to rename the ContextKey by hand? Obviously, that's no big deal for one applied migration, however it'd be a huge pain to do for dozens of applied migrations.

Answer 1

I was stuck in this for a long time and asked-and-answered-it here. In the EF docs you can find the explanation about context keys here.You should create custom migration configuration like this :

 public class MyMigrationConfiguration : DbMigrationsConfiguration<MyMigrationContext>
{
    public MyMigrationConfiguration ()
    {
        AutomaticMigrationsEnabled = false;
        AutomaticMigrationDataLossAllowed = false;
        MigrationsNamespace = "My.Migrations.Assembly";
        MigrationsDirectory = "My/Migrations/Directory";
        ContextKey = "MyContexKey"; // You MUST set this for every migration context
    }
}