Lock in $30 Savings on PRO—Offer Ends Soon! ⏳
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
54
とある EM の初めての育休からの学び
clown0082
1
4.8k
The history of Javascript frameworks: changes in front-end design philosophy
clown0082
2
200
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
640
JavaScript × Mathematics go to Digital Art
clown0082
1
430
In-house study group at YUMEMI
clown0082
0
220
Playing Ionic Logo by p5.js
clown0082
0
310
Other Decks in Technology
See All in Technology
AI駆動開発の実践とその未来
eltociear
0
120
今年のデータ・ML系アップデートと気になるアプデのご紹介
nayuts
1
460
AWSを使う上で最低限知っておきたいセキュリティ研修を社内で実施した話 ~みんなでやるセキュリティ~
maimyyym
2
1.7k
Databricks向けJupyter Kernelでデータサイエンティストの開発環境をAI-Readyにする / Data+AI World Tour Tokyo After Party
genda
1
520
大企業でもできる!ボトムアップで拡大させるプラットフォームの作り方
findy_eventslides
1
820
2025年 開発生産「可能」性向上報告 サイロ解消からチームが能動性を獲得するまで/ 20251216 Naoki Takahashi
shift_evolve
PRO
1
200
生成AIを利用するだけでなく、投資できる組織へ / Becoming an Organization That Invests in GenAI
kaminashi
0
100
Sansanが実践する Platform EngineeringとSREの協創
sansantech
PRO
2
910
IAMユーザーゼロの運用は果たして可能なのか
yama3133
1
460
AWS Security Agentの紹介/introducing-aws-security-agent
tomoki10
0
300
プロンプトやエージェントを自動的に作る方法
shibuiwilliam
12
10k
AIプラットフォームにおけるMLflowの利用について
lycorptech_jp
PRO
1
170
Featured
See All Featured
Building an army of robots
kneath
306
46k
The Hidden Cost of Media on the Web [PixelPalooza 2025]
tammyeverts
1
100
The Myth of the Modular Monolith - Day 2 Keynote - Rails World 2024
eileencodes
26
3.2k
Testing 201, or: Great Expectations
jmmastey
46
7.8k
How to train your dragon (web standard)
notwaldorf
97
6.4k
Fight the Zombie Pattern Library - RWD Summit 2016
marcelosomers
234
17k
Keith and Marios Guide to Fast Websites
keithpitt
413
23k
How GitHub (no longer) Works
holman
316
140k
Statistics for Hackers
jakevdp
799
230k
Docker and Python
trallard
47
3.7k
KATA
mclloyd
PRO
33
15k
Dealing with People You Can't Stand - Big Design 2015
cassininazir
367
27k
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