What did I do wrong with my Rails migrations for Heroku?

Question

I'm trying to add my Address table's text property as the address property of my Brewery table, then delete the Address table. I'm doing this on Heroku after a git push heroku master by running heroku run rake db:migrate.

My first migration which creates the new field for the data works fine. But my second migration fails immediately- it says it can't find the Address table. My third migration never runs, but it's the one that was supposed to delete the Address table to tidy everything up.

What am I doing wrong? These migrations worked on my local box, but are failing on Heroku:

1:

class AddAddressStringToBrewery < ActiveRecord::Migration
  def change
    add_column :breweries, :address, :string
  end
end

2:

class MoveAddressToString < ActiveRecord::Migration
  def change
    Address.all.each do |address|
      brewery = address.brewery
      brewery.update(address: address.text)
    end
  end
end

3:

class DropAddressTable < ActiveRecord::Migration
  def change
    drop_table :addresses
  end
end

My best guess is that Heroku is reading my schema and dropping the table, before running my migrations. I could always stage these migrations in individual git commits to force it to work, but I'd really like to know where I went wrong.

Thanks!

Answer 1

I realized what I did wrong. My push to Heroku with these migrations also deleted my Address model. When I ran them in my local environment it was before I cleaned up the old Address code. I added the Address model back long enough to run the migrations and they all run fine.