Using Rails Migration on different database than standard "production" or "development"

Question

Hi!

I have a rails project running that defines the standard production:, :development and :test DB-connections in config/database.yml

In addition I have a quiz_development: and quiz_production: definition pointing to a differnet host/db/user/password

My goal now is to define a Migration that uses "quiz_#{RAILS_ENV}`" as its database configuration.

What I have tried (and failed):

• Setting ActiveRecord::Base.connection in the Migration file
• Changing the db:migrate task in rails to set ActiveRecord::Base.connection there

Question:

How can I make rake db:migrate use that other database definition?

Thanks, Frank

Answer 1

Have you tried using quiz_development as a RAILS_ENV (instead of trying to get it to use "quiz_#{RAILS_ENV}")?

RAILS_ENV=quiz_development rake db:migrate

Answer 2

You can also move all your quiz_ related migrations into a separate subfolder in the db/ directory and then add rake tasks mirroring the regular migration functionality but that looks for the migrations in that subdirectory. Not super-elegant perhaps but it works. You can copy and paste the rake tasks already in rails and just modify them a bit.

Answer 3

You should define the other databases/environments in /config/environments.

After that you can use the following command to migrate that specific environment.

rake db:migrate RAILS_ENV=customenvironment

Answer 4

Hello,

A bit late, but I was dealing with this problem today and I came up with this custom rake task:

namespace :db do
  desc "Apply db tasks in custom databases, for example  rake db:alter[db:migrate,test-es] applies db:migrate on the database defined as test-es in databases.yml"
  task :alter, [:task,:database] => [:environment] do |t, args|
    require 'activerecord'
    puts "Applying #{args.task} on #{args.database}"
    ActiveRecord::Base.establish_connection(ActiveRecord::Base.configurations[args.database])
    Rake::Task[args.task].invoke
  end
end