After making some major modifications to a Rails app that is already in production, I pushed everything to the server, ran my migrations and then discovered major problems.
It turns out that there are 2 database columns that have not been created in my production database by the migrations. When I look through my migrations there isn't one that creates those columns. I'm guessing I made an error with git at some point and have lost those files.
What I want to know is how to safely create those columns in my production database. If I just create a new migration to make those 2 columns, push to production and run the migrations, I presume things will work, but will this cause problems when these migrations get run on my development database with the columns already there?
Yes this will cause some problem on your develompent database, just comment add_column commands during running rake db:migrate on your development database, and uncomment after that operation.