Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
【2018/09/18 Otemachi.rb#9】君(退会したユーザ)の名は。
Search
Shu OGAWARA
September 18, 2018
Technology
0
490
【2018/09/18 Otemachi.rb#9】君(退会したユーザ)の名は。
2018/09/18のOtemachi.rb#9での発表資料です。久しぶりのRailsネタです。
Shu OGAWARA
September 18, 2018
Tweet
Share
More Decks by Shu OGAWARA
See All by Shu OGAWARA
Rubyはなぜ「たのしい」のか? / Why is Ruby a programmers' best friend? #tqrk15
expajp
5
1.9k
エンジニアリングマネージャーはどう学んでいくのか #devsumi / How Do Engineering Managers Continue to Learn and Grow?
expajp
8
3.8k
RubyKaigi参加歴をふりかえる / Looking Back on My RubyKaigi Participation History #kaigieffectLT
expajp
3
410
わたしのメタ学習 / My Own Meta Learning #shinjukurb
expajp
0
390
ActiveSupport::Concernで開くメタプログラミングの扉 #heiseirubykaigi / The door of meta-programing is opened by ActiveSupport::Concern
expajp
1
2.2k
実践Railsアプリケーション設計 #meetup_rails / Practical Rails Application Design
expajp
4
39k
【2019/07/06 TamaRuby会議01】brainf*ck処理系で理解するパターンマッチングをつかった疎結合な実装
expajp
2
2.6k
その正規表現、異議あり! 〜 ReDoSについて
expajp
2
5.5k
【2018/12/08 RailsDM】「あの人」に学ぶ!駆け出しRailsエンジニアの日常の過ごし方
expajp
10
1.3k
Other Decks in Technology
See All in Technology
完全自律型AIエージェントとAgentic Workflow〜ワークフロー構築という現実解
pharma_x_tech
0
350
Godot Engineについて調べてみた
unsoluble_sugar
0
400
Amazon Q Developerで.NET Frameworkプロジェクトをモダナイズしてみた
kenichirokimura
1
200
[IBM TechXchange Dojo]Watson Discoveryとwatsonx.aiでRAGを実現!座学①
siyuanzh09
0
110
商品レコメンドでのexplicit negative feedbackの活用
alpicola
2
360
I could be Wrong!! - Learning from Agile Experts
kawaguti
PRO
8
3.4k
Oracle Base Database Service:サービス概要のご紹介
oracle4engineer
PRO
1
16k
技術に触れたり、顔を出そう
maruto
1
150
re:Invent 2024のふりかえり
beli68
0
110
30分でわかる「リスクから学ぶKubernetesコンテナセキュリティ」/30min-k8s-container-sec
mochizuki875
3
450
0→1事業こそPMは営業すべし / pmconf #落選お披露目 / PM should do sales in zero to one
roki_n_
PRO
1
1.5k
機械学習を「社会実装」するということ 2025年版 / Social Implementation of Machine Learning 2025 Version
moepy_stats
5
1.1k
Featured
See All Featured
The Cost Of JavaScript in 2023
addyosmani
46
7.2k
Designing for humans not robots
tammielis
250
25k
What's in a price? How to price your products and services
michaelherold
244
12k
Java REST API Framework Comparison - PWX 2021
mraible
28
8.3k
4 Signs Your Business is Dying
shpigford
182
22k
Practical Tips for Bootstrapping Information Extraction Pipelines
honnibal
PRO
10
870
Designing Experiences People Love
moore
139
23k
Bash Introduction
62gerente
610
210k
Principles of Awesome APIs and How to Build Them.
keavy
126
17k
VelocityConf: Rendering Performance Case Studies
addyosmani
327
24k
Making Projects Easy
brettharned
116
6k
Testing 201, or: Great Expectations
jmmastey
41
7.2k
Transcript
܅ ͷ ໊ ɻ ୀձͨ͠Ϣʔβ 0UFNBDIJSC 4IV0("8"3" !FYQBKQ 1IPUPCZ/FJM3PTFOTUFDI
PO6OTQMBTI
1 !
Rails
n & %(@expajp) – ! – 3
– Ruby/Rails(1 • Project Euler 100 • Vue.js+ – # ' " – *$ )
CM
View
n post creatornil
n post
n DB posts ! user_id NULL " 0 #
n post
n DB posts ! user_id NULL " 0 #
,
n B83+,.02@A' " % – ,.020 ;E(15*,47<: $#D=
n View6-/)'C9 ? " % &" – View!6-/)'? – DRY>%
n & #$ n
'!" %
N+1
N+1 Q . L S 0 N Q . 11
N+1 / Eager Loading - Rails Webook https://ruby-rails.hatenadiary.com/entry/20141108/1415418367 ’’
N+1 n DB
→
٫Լʂ
CTO
n Active Record/. creator_id0 - * n Decorator,#4(
*&!)$+ " → post'%*&!)30$+ → DRY21
Active Record
Decorator
View
ҟٞ͋Γʂ
CH*-&0c$a2&16$ >TO@L&Kg\N MB/&K$ ;5&F Z$ [Ra2 VI% 43$QWU *-&P
D$a2Gb# $ $ SY9X`d$=^!A]?(.+'),JE" $a2&<7:f_<$ The WyCash Portfolio Management System http://c2.com/doc/oopsla92.html heSY8TO - Wikipedia ’’
n 06:?)<5DE n Decorator7*F2(> +' -4@1% –
"#! . n gem9(,38C – B/) & ;A3 $/=
NullUser, SystemUser
n Decorator Post creator n User
full_name n Post NullUser, SystemUser – full_name ! n creator User, NullUser, SystemUser
User
NullUser, SystemUser
Post
!
n DB5-6 & %!* #($). –
View,1 '! n 70+4 "*/ 32
n )$ " !'( n
View#*%&
1. 2.
3. NullUser, SystemUser
!
n ;&B5$ – ?< 12$'*/+-@ – full_nameA03 %
n ;D …… – 89" FE – DRY" n ;&,(-.4=6,). C :$# >7 !
n (#&')!% #@ n Rails0-= – *"$!,E?28DRYF<251A
– I74C>6 n +3D 9:HJ;B – /.G+3D