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BP Study #15
翱搁マッパー対決?２００８

Active Recordとか

自己紹介

? 尾崎智仁
? ID:yuroyoro
? フリーエンジニア
? Java、最近はScala

翱搁マッパー
対決
ってことで

20081128 Bp Study#15 Active Record

ActiveRecordって?

?RailsでのO/R Mapper
?Railsなくてもつかえるけど
?ActiveRecordパターン
?Mapping定義が簡単
?class Member < ActiveRecord::Base

ActiveRecordって?

?DDL関係はMigrationで
?Act_as_*で振る舞いを拡張可能
?動的ファインダ
?Lazy Loading
?Named Scope -&驳迟;イカス

ActiveRecordを使う準備

?MySqlをインストールしておく
?MySqlにDatabaseを作っておく
?Railsアプリを生成する
?Migration書く

ActiveRecordを使う - 1
Railアプリを生成
$ rails ARTest
create
create app/controllers
create app/helpers
create app/models
create app/views/layouts
create config/environments
create config/initializers
create db
create doc

Modelを生成する
$ ./script/generate model member username:string password:string
? sex:decimal birthday:datetime last_login_time:timestamp

:0:Warning: Gem::SourceIndex#search support for Regexp patterns is deprecated

exists app/models/

exists test/unit/

exists test/fixtures/

create app/models/member.rb

create test/unit/member_test.rb

create test/fixtures/members.yml

create db/migrate

create db/migrate/20081127123415_create_members.rb

Migrateする
$ rake db:migrate
(in /Users/ozaki/dev/Project/sandbox/work/ARTest)
== 20081127123415 CreateMembers: migrating
====================================
-- create_table(:members)
-> 0.0049s
== 20081127123415 CreateMembers: migrated (0.0054s)
===========================

Consoleで確認
$ script/console
Loading development environment (Rails 2.1.0)
>> member=Member.find(:all)
=> []
>> Member.create
#<Member id: 1, username: nil, password: nil, first_name: nil,
last_name: nil, sex: nil, birthday: nil, last_login_time: nil,
created_at: quot;2008-11-27 13:16:47quot;, updated_at: quot;2008-11-27
13:16:47quot;>
>> Member.find(1)
=> #<Member id: 1, username: nil, password: nil, first_name: nil,
last_name: nil, sex: nil, birthday: nil, last_login_time: nil,
created_at: quot;2008-11-27 13:16:47quot;, updated_at: quot;2008-11-27
13:16:47”>

動的な属性ベースのファインダ

>> Member.find_by_username('Test2')
=> #<Member id: 2, username: quot;Test2quot;, password: nil, first_name:
nil, last_name: nil, sex: nil, birthday: nil, last_login_time:
nil, created_at: quot;2008-11-27 13:17:04quot;, updated_at: quot;2008-11-
27 13:21:14quot;>

関連の設定
class Employee< ActiveRecord::Base
belongs_to :department
has_many :roles ,:through => :belongs

End

class Department< ActiveRecord::Base
has_many :employees
acts_as_tree :order => quot;idquot;
end

Named_scope
class Member < ActiveRecord::Base
named_scope :male,
:conditions=>[quot;sex = ?quot;,1]

named_scope :recent,
lambda {|*args| {:conditions =>
[quot;updated_at > ?quot;, args.first ||
1.day.ago]} }
end

ActiveRecord まとめ

よかったさがし

?Mapping定義は楽
?Pluginいっぱい
?Lazy Loading
?Irb上で簡単確認

ActiveRecord まとめ

Disってみる
Disってみる

?リファクタリング大変
?Migrationは計画的に
?IDEの補完が…
?Joinとかにがて

ActiveObjectsって?
?ARパターンのJava実装
?Interfaceにgetter/setterで
?manager.migrate(Person.class);
?EntityManager
?アノテーション
?http://d.hatena.ne.jp/nattou_cur
ry_2/

ご清聴
ありがとう
ございました

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20081128 Bp Study#15 Active Record

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20081128 Bp Study#15 Active Record