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
What is "Entity" in DDD?
Search
kkeeth
March 10, 2020
Technology
0
190
What is "Entity" in DDD?
kkeeth
March 10, 2020
Tweet
Share
More Decks by kkeeth
See All by kkeeth
Programming to play with p5.js
clown0082
0
65
とある EM の初めての育休からの学び
clown0082
1
5k
The history of Javascript frameworks: changes in front-end design philosophy
clown0082
2
210
Visually experience the beauty of mathematics with p5.js
clown0082
1
3.2k
Rediscover the joy of coding with Creative Coding
clown0082
0
1.8k
全員が意思決定する会社で開発者体験や生産性を見る大変さについて
clown0082
0
650
JavaScript × Mathematics go to Digital Art
clown0082
1
440
In-house study group at YUMEMI
clown0082
0
230
Playing Ionic Logo by p5.js
clown0082
0
320
Other Decks in Technology
See All in Technology
Kiro IDEのドキュメントを全部読んだので地味だけどちょっと嬉しい機能を紹介する
khmoryz
0
200
usermode linux without MMU - fosdem2026 kernel devroom
thehajime
0
240
量子クラウドサービスの裏側 〜Deep Dive into OQTOPUS〜
oqtopus
0
130
FinTech SREのAWSサービス活用/Leveraging AWS Services in FinTech SRE
maaaato
0
130
インフラエンジニア必見!Kubernetesを用いたクラウドネイティブ設計ポイント大全
daitak
1
370
Webhook best practices for rock solid and resilient deployments
glaforge
2
300
SREが向き合う大規模リアーキテクチャ 〜信頼性とアジリティの両立〜
zepprix
0
460
10Xにおける品質保証活動の全体像と改善 #no_more_wait_for_test
nihonbuson
PRO
2
310
AIと新時代を切り拓く。これからのSREとメルカリIBISの挑戦
0gm
1
2.6k
Claude_CodeでSEOを最適化する_AI_Ops_Community_Vol.2__マーケティングx_AIはここまで進化した.pdf
riku_423
2
590
予期せぬコストの急増を障害のように扱う――「コスト版ポストモーテム」の導入とその後の改善
muziyoshiz
1
2k
Cosmos World Foundation Model Platform for Physical AI
takmin
0
930
Featured
See All Featured
SEO for Brand Visibility & Recognition
aleyda
0
4.2k
How To Stay Up To Date on Web Technology
chriscoyier
791
250k
The Myth of the Modular Monolith - Day 2 Keynote - Rails World 2024
eileencodes
26
3.3k
Exploring anti-patterns in Rails
aemeredith
2
250
The Cost Of JavaScript in 2023
addyosmani
55
9.5k
技術選定の審美眼(2025年版) / Understanding the Spiral of Technologies 2025 edition
twada
PRO
117
110k
Principles of Awesome APIs and How to Build Them.
keavy
128
17k
My Coaching Mixtape
mlcsv
0
48
Fashionably flexible responsive web design (full day workshop)
malarkey
408
66k
Building Experiences: Design Systems, User Experience, and Full Site Editing
marktimemedia
0
410
Public Speaking Without Barfing On Your Shoes - THAT 2023
reverentgeek
1
310
Color Theory Basics | Prateek | Gurzu
gurzu
0
200
Transcript
What is “Entity” in DDD? k-kuwahara @kuwahara_jsri @clown0082 Mar 10,
2020 Active Book Dialogue @Yumemi
const my_info = { Workplace: ‘Yumemi Inc’, Position1: ‘Servant Leader
of FET’, Position2: ‘CEO(secondary)’, Community: ‘Riot.js, Ionic, DIST’, PokemonGO: ‘TL40’ } About me
npm/~kkeeth
github.com/riot
definition of “Entity”
embody Domain Model Domain Object definitin of “Entity”
embody Domain Model definitin of “Entity” Domain Object But, there
are 2 objects. So, “Value Object”, “Entity”
What is the difference between “Value Object” and “Entity”?
the difference Value Object Entity diff attributes/variables identity property immutability
valiability change exchange/substitution behavior
Value Object
Value Object Name: John Age: 32 Gender: Male Name: Emily
Age: 27 Gender: Female
Value Object Name: John Age: 32 Gender: Male Name: John
Age: 32 Gender: Male
Entity
Entity Name: John Age: 32 Gender: Male Name: Emily Age:
27 Gender: Female
Entity Name: John Age: 32 Gender: Male Name: John Age:
32 Gender: Male
How do “Entity” identify each other?
Entity ID: 12345 Name: John Age: 32 Gender: Male ID:
98765 Name: John Age: 32 Gender: Male
Entity ID: 12345 Name: John Age: 32 Gender: Male ID:
98765 Name: John Age: 32 Gender: Male identity identity ID: 12345 ID: 98765
Merits of “Entity”
merits of “Entity” Code is more documentable Make changes in
our domain easier to communicate to your code
merits of “Entity”
embody merits of “Entity”
Let’s join DDD!!
None