title: My production database is missing some columns. How can I safely restore them?
body: <p>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.</p>
  
  <p>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.</p>
  
  <p>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?</p>