Question

While I run the db:migrate task, the migration doesn’t actually happen.
Here’s the code of my Rakefile:

namespace :db do
  desc "Migrate the database through scripts in lib/generators/facebook_event_fetcher/install/templates. Target specific version with VERSION=x"
  task :migrate => :environment do
    ActiveRecord::Migration.verbose = true
    #ActiveRecord::Migrator.migrate('db/migrate', ENV["VERSION"] ? ENV["VERSION"].to_i : nil )
    ActiveRecord::Migrator.migrate('lib/generators/facebook_event_fetcher/install/templates', nil)
  end

  task :environment do
    ActiveRecord::Base.establish_connection(YAML.load_file("config/database.yml"))
    ActiveRecord::Base.logger = Logger.new(File.open('db/database.log', 'a')) 
  end
end

You can take a closer look at the Github repo:
https://github.com/mabounassif/facebook_event_fetcher/blob/master/Rakefile#L42

Why wouldn’t the migration be triggered??

Answer 1

ActiveRecord::Migrator needs migration files to start with a number or timestamp so it can keep track of versions. Here is what I did to get a migration running in your repo:

facebook_event_fetcher/lib/generators/facebook_event_fetcher/install/templates$ mv create_delayed_jobs.rb 001_create_delayed_jobs.rb
facebook_event_fetcher/lib/generators/facebook_event_fetcher/install/templates$ cd ../../../../..
facebook_event_fetcher/lib$ cd ..
facebook_event_fetcher$ rake db:migrate
==  CreateDelayedJobs: migrating ==============================================
-- create_table(:delayed_jobs, {:force=>true})
   -> 0.0076s
-- add_index(:delayed_jobs, [:priority, :run_at], {:name=>"delayed_jobs_priority"})
   -> 0.0004s
==  CreateDelayedJobs: migrated (0.0081s) =====================================