Reset Entity-Framework Migrations

You need to delete the state:

1. Delete the migrations folder in your project

2. Delete the __MigrationHistory table in your database (may be under system tables)

Then run the following command in the Package Manager Console:

Enable-Migrations -EnableAutomaticMigrations -Force

Use with or without -EnableAutomaticMigrations

And finally, you can run:

Add-Migration Initial

Reset Entity-Framework Migrations

原文：http://www.cnblogs.com/dupeng0811/p/Reset-Entity-Framework-Migrations.html