$30 off During Our Annual Pro Sale. View Details »

What is "Entity" in DDD?

kkeeth
March 10, 2020

What is "Entity" in DDD?

kkeeth

March 10, 2020
Tweet

More Decks by kkeeth

Other Decks in Technology

Transcript

  1. What is “Entity” in DDD?
    k-kuwahara @kuwahara_jsri @clown0082
    Mar 10, 2020 Active Book Dialogue @Yumemi

    View Slide

  2. const my_info = {
    Workplace: ‘Yumemi Inc’,
    Position1: ‘Servant Leader of FET’,
    Position2: ‘CEO(secondary)’,
    Community: ‘Riot.js, Ionic, DIST’,
    PokemonGO: ‘TL40’
    }
    About me

    View Slide

  3. npm/~kkeeth

    View Slide

  4. github.com/riot

    View Slide

  5. definition of “Entity”

    View Slide

  6. embody
    Domain
    Model
    Domain
    Object
    definitin of “Entity”

    View Slide

  7. embody
    Domain
    Model
    definitin of “Entity”
    Domain
    Object
    But, there are 2 objects. So,
    “Value Object”, “Entity”

    View Slide

  8. What is the difference between
    “Value Object” and “Entity”?

    View Slide

  9. the difference
    Value Object Entity
    diff attributes/variables identity
    property immutability valiability
    change exchange/substitution behavior

    View Slide

  10. Value Object

    View Slide

  11. Value Object
    Name: John
    Age: 32
    Gender: Male
    Name: Emily
    Age: 27
    Gender: Female

    View Slide

  12. Value Object
    Name: John
    Age: 32
    Gender: Male
    Name: John
    Age: 32
    Gender: Male

    View Slide

  13. Entity

    View Slide

  14. Entity
    Name: John
    Age: 32
    Gender: Male
    Name: Emily
    Age: 27
    Gender: Female

    View Slide

  15. Entity
    Name: John
    Age: 32
    Gender: Male
    Name: John
    Age: 32
    Gender: Male

    View Slide

  16. How do “Entity”
    identify each other?

    View Slide

  17. Entity
    ID: 12345
    Name: John
    Age: 32
    Gender: Male
    ID: 98765
    Name: John
    Age: 32
    Gender: Male

    View Slide

  18. Entity
    ID: 12345
    Name: John
    Age: 32
    Gender: Male
    ID: 98765
    Name: John
    Age: 32
    Gender: Male
    identity identity
    ID: 12345 ID: 98765

    View Slide

  19. Merits of “Entity”

    View Slide

  20. merits of “Entity”
    Code is more documentable
    Make changes in our domain
    easier to communicate to
    your code

    View Slide

  21. merits of “Entity”

    View Slide

  22. embody
    merits of “Entity”

    View Slide

  23. Let’s join DDD!!

    View Slide

  24. View Slide