Ubuntu 14.04 ruby2.1.2 で ActiveRecord4.1.6 を使用し、postgresql4.1.6 へアクセス

まずはdatabase 確認

sudo su postgres -c psql

install activerecord,pg

mkdir -p ~/works/99_sample/02_activerecord
cd ~/works/99_sample/02_activerecord
gem install activerecord
gem install pg
gem list

DBユーザtest_nameを作成しておく

sudo su postgres -c psql
create role test_name superuser login;
\password test_name
  Enter new password: test_name
  Enter it again: test_name
create database test_name;

config/database.yml

mkdir -p config && vim config/database.yml

db:
  production:
    adapter:  postgresql
    host:     localhost
    username: test_name
    password: test_name
    database: test_name

  development:
    adapter:  postgresql
    host:     localhost
    username: test_name
    password: test_name
    database: test_name

db/migrate配下に、３ファイルを配置(rails環境からコピー)

mkdir -p db/migrate

rails_no_entity.01.rb
rails_no_entity.02.rb
rails_no_entity.03.rb

Rakefile作成（テスト用ルートディレクトリ直下に作成）

vim Rakefile

require 'active_record'
require 'yaml'
#require 'erb'
require 'logger'

task :default => :migrate

desc "Migrate database"
task :migrate => :environment do
  ActiveRecord::Migrator.migrate('db/migrate', ENV["VERSION"] ? ENV["VERSION"].to_i : nil )
end

task :environment do
  #dbconfig = YAML.load(ERB.new(File.read('config/database.yml')).result)
  dbconfig = YAML.load_file('./config/database.yml')

  ActiveRecord::Base.establish_connection(dbconfig["db"]["development"])
  ActiveRecord::Base.logger = Logger.new('db/database.log')
end

DB作成実行

rake