What is the best way to resolve Rails orphaned migrations?

Question

I have been switching between branches in a project and each of them have different migrations... This is the scenario:

$ rake db:migrate:status

<

Answer 1

Migrations are stored in your database. If you want to remove the abandoned migrations, remove them from the db.

Example for Postgres:

1. Open psql:

   psql
   

2. Connect to your db:

   \c your_database
   

3. If you're curious, display schema_migrations:

   SELECT * FROM schema_migrations;
   

4. If you're curious, check if the abandoned migrations are present:

   SELECT version FROM schema_migrations WHERE version IN 
   ('20130320144219', '20130320161939', '20130320184628', '20130403190042',
    '20130403195300', '20130403214000', '20130410194222');
   

5. Delete them:

   DELETE FROM schema_migrations WHERE version IN ();
   

Now if you run bundle exec rake db:migrate:status, you'll see the orphaned migrations have been successfully removed.