Last Updated: June 22, 2016

ActiveRecord create, drop and migrations without Rails

Here's an Active Record (> 5) create, drop and migration task w/o rails based on the Wes Bailey Article.

created by: charly-palencia & Erlinis
Details:
* Only PostgreSQL database

database_connection.rb

require 'active_record'
require 'erb'

module DatabaseConnection
 def self.connect!(env)
 #Ref https://github.com/puma/puma#clustered-mode
 ActiveSupport.on_load(:active_record) do
 ::ActiveRecord::Base.connection_pool.disconnect! if ::ActiveRecord::Base.connected?
 ::ActiveRecord::Base.configurations = YAML.load(ERB.new(File.read("db/config.yml")).result) || {}
 config = ::ActiveRecord::Base.configurations[env.to_s]
 ::ActiveRecord::Base.establish_connection(config)
 end
 end
end

tasks/database.rb

require 'yaml'
require 'config/database_connection'
require 'active_record'

namespace :db do

 task :environment do
 path = File.join(File.dirname(__FILE__), '../db/migrate')
 migrations_paths = [path]
 DATABASE_ENV = ENV['RACK_ENV'] || 'development'
 MIGRATIONS_DIR = ENV['MIGRATIONS_DIR'] || migrations_paths
 end

 task :configuration => :environment do
 @config = YAML.load(ERB.new(File.read("db/config.yml")).result)[DATABASE_ENV]
 end

 task :configure_connection => :configuration do
 DatabaseConnection.connect!(DATABASE_ENV)
 ActiveRecord::Base.logger = Logger.new STDOUT if @config['logger']
 end

 desc 'Create the database from db/config.yml for the current DATABASE_ENV'
 task :create => :configure_connection do
 database = ActiveRecord::Tasks::PostgreSQLDatabaseTasks.new(@config)
 database.create
 puts "Database created"
 end

 desc 'Drops the database for the current DATABASE_ENV'
 task :drop => :configure_connection do
 database = ActiveRecord::Tasks::PostgreSQLDatabaseTasks.new(@config)
 database.drop
 puts "Database dropped"
 end

 desc 'Migrate the database (options: VERSION=x, VERBOSE=false).'
 task :migrate => :configure_connection do
 begin
 verbose = ENV["VERBOSE"] ? ENV["VERBOSE"] == "true" : true
 version = ENV["VERSION"] ? ENV["VERSION"].to_i : nil
 scope = ENV['SCOPE']
 verbose_was, ActiveRecord::Migration.verbose = ActiveRecord::Migration.verbose, verbose
 ActiveRecord::Migrator.migrate(MIGRATIONS_DIR, version) do |migration|
 scope.blank? || scope == migration.scope
 end
 ActiveRecord::Base.clear_cache!
 ensure
 ActiveRecord::Migration.verbose = verbose_was
 end
 end

 desc 'Rolls the schema back to the previous version (specify steps w/ STEP=n).'
 task :rollback => :configure_connection do
 step = ENV['STEP'] ? ENV['STEP'].to_i : 1
 ActiveRecord::Migrator.rollback(MIGRATIONS_DIR, step)
 end

#ruby

#rails

#migration