データベースのスキーマ変更と開発環境のデータ管理をいい感じにする

$ bundle gem my_db_tasks
$ cd my_db_tasks

spec.add_dependency "activerecord", "~> 5.0"
spec.add_dependency “mysql2"

env = ENV['ENV'] || 'development'
db_config = YAML.load(ERB.new(File.read('config/database.yml')).result)

task :environment do
  ActiveRecord::Base.logger = Logger.new(STDOUT)
  ActiveRecord::Base.schema_format = :sql
  ActiveRecord::Base.establish_connection(db_config[env])
end

namespace :db do
  task :load_config do
    ActiveRecord::Tasks::DatabaseTasks.env = env
    ActiveRecord::Tasks::DatabaseTasks.db_dir = 'db'
    ActiveRecord::Tasks::DatabaseTasks.database_configuration = db_config
    ActiveRecord::Tasks::DatabaseTasks.migrations_paths = ['db/migrate']
    ActiveRecord::Tasks::DatabaseTasks.root = Pathname.new(Dir.pwd)

    if env != 'development'
      ActiveRecord::Base.dump_schema_after_migration = false
    end
  end
end

load "active_record/railties/databases.rake"

defaults: &defaults
  adapter: mysql2
  port: 3306

development:
  <<: *defaults
  host: localhost
  username: root
  password:
  database: my_db_tasks_development

$ bundle exec rake db:create
Created database 'my_db_tasks_development'

$ bin/generate-migration CreateUsers
create  db/migrate/20170407170908_create_users.rb

class CreateUsers < ActiveRecord::Migration
  def up
    execute <<-SQL
      CREATE TABLE users(
        id int not null auto_increment,
        name varchar(255) not null,
        primary key (id)
      ) ENGINE=InnoDB
    SQL
  end

  def down
    execute <<-SQL
      DROP TABLE users
    SQL
  end
end

$ bundle exec rake db:migrate

$ bundle exec rake db:migrate:status
D, [2017-04-07T17:16:56.533945 #76786] DEBUG -- :    (0.2ms)  SELECT `schema_migrations`.`version` FROM `schema_migrations`

database: my_db_tasks_development

Status   Migration ID    Migration Name
--------------------------------------------------
   up     20170407170908  Create users

mysql> select * from users ;
+----+--------+
| id | name   |
+----+--------+
|  1 | ichiro |
|  2 | jiro   |
+----+--------+
2 rows in set (0.00 sec)

$ bundle exec rake db:structure:dump
D, [2017-04-07T17:28:14.434991 #77672] DEBUG -- :    (0.3ms)  SELECT `schema_migrations`.`version` FROM `schema_migrations` ORDER BY version

diff --git a/db/structure.sql b/db/structure.sql
index d306da4..d721e6b 100644
--- a/db/structure.sql
+++ b/db/structure.sql
@@ -55,7 +55,7 @@ CREATE TABLE `users` (
   `id` int(11) NOT NULL AUTO_INCREMENT,
   `name` varchar(255) NOT NULL,
   PRIMARY KEY (`id`)
-) ENGINE=InnoDB DEFAULT CHARSET=utf8;
+) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8;
/*!40101 SET character_set_client = @saved_cs_client */;

--
@@ -71,7 +71,7 @@ CREATE TABLE `users` (
/*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;
/*!40111 SET SQL_NOTES=@OLD_SQL_NOTES */;

--- Dump completed on 2017-04-07 17:15:25
+-- Dump completed on 2017-04-07 17:28:14
INSERT INTO `schema_migrations` (version) VALUES
('20170407170908’);

namespace :db do
  namespace :structure do
    desc "Remove AUTO_INCREMENT table option from the db/structure.sql file"
    task :remove_auto_increment_table_option do
      ActiveRecord::Base.logger.debug "Remove AUTO_INCREMENT table option from the db/structure.sql file"
      structure = File.read('./db/structure.sql').gsub(/\sAUTO_INCREMENT=\d+/, '')
      File.open('./db/structure.sql', 'w') do |f|
        f.write(structure)
      end
    end
  end
end

Rake::Task['db:structure:dump'].enhance do
  Rake::Task['db:structure:remove_auto_increment_table_option'].invoke
end

module MyDbTasks
  class SeedLoader
    def initialize(db_config)
      @db_config = db_config
      @logger = Logger.new(STDOUT)
      @logger.info "database: #{@db_config}"
    end

    def load_seed
      @logger.info 'Load seed data start.'
      # ここでシードデータをロードする
      @logger.info 'Load seed data end.'
    end
  end
end

ActiveRecord::Tasks::DatabaseTasks.seed_loader = MyDbTasks::SeedLoader.new(db_config[env])

$ bundle exec rake db:seed
I, [2017-04-07T17:44:45.782157 #78647]  INFO -- : database: {"adapter"=>"mysql2", "host"=>"localhost", "username"=>"root", "password"=>nil, "database"=>"my_db_tasks_development", "port"=>3306}
D, [2017-04-07T17:44:45.848587 #78647] DEBUG -- :   ActiveRecord::SchemaMigration Load (0.3ms)  SELECT `schema_migrations`.* FROM `schema_migrations`
I, [2017-04-07T17:44:45.858685 #78647]  INFO -- : Load seed data start.
I, [2017-04-07T17:44:45.858727 #78647]  INFO -- : Load seed data end.

$ bundle exec rake -T -A | grep master_data
rake colorme:master_data:create                       # Creates colorme master data
rake colorme:master_data:drop                         # Drops colorme master data
rake colorme:master_data:dump                         # Create master data sql files in db/master_data/sql directory
rake colorme:master_data:load_config                  #
rake colorme:master_data:reset                        #

$ bundle exec rake db:setup
$ bundle exec rake colorme:master_data:create