This is speaker - Brinkley shared his talk about value object chapter in "Implementing Domain-Driven Design" Book in DDD Taiwan study group.

1. DDD Reading Club Sharing
Ch. 6 Value Object
Brinkley

2. Introduction
❏ Value Characteristics
❏ Integrated with Minimalism
❏ Standard Types Expressed as Values
❏ Testing Value Objects
❏ Persisting Value Objects

3. Value Characteristics
❏ Measures, Quantifies, or Describes
❏ Immutable
❏ Conceptual Whole
❏ Replaceability
❏ Value Equality
❏ Side-Effect-Free Behavior

4. Example
❏ 玩家的錢包餘額有1000塊人民幣，表示了兩個屬性，1000塊與人民幣
，單獨一個屬性都無法表示錢包餘額

5. Example
❏ 在建構函式中傳入Value Object所需的參數，並初始化Value Object的
屬性

6. Example
❏ 玩家的錢包餘額有1000塊人民幣，下注後要扣款100塊，基於Value
Object is an immutable的特性，要如何改變Value Object內的值?

7. Example
❏ 如何判斷兩個Value Object是相等的

8. Integrated with Minimalism
❏ Where possible use Value Objects to model concepts in the
downstream Context when objects from the upstream Context flow in

9. Integrated with Minimalism

10. Standard Types Expressed as Values
❏ Enum
❏ State Pattern

11. Testing Value Objects
❏ Your model tests should have meaning to your domain experts
❏ The state of the Value Object was guaranteed immutable for every

12. Persisting Value Objects
❏ ORM and Single Value Objects
❏ ORM and Many Values Serialized into a Single Column
❏ ORM and Many Values Backed by a Database Entity
❏ ORM and Many Values Backed by a Join Table
❏ ORM and Enum-as-State Objects

13. ORM and Single Value Objects
❏ Store each of the attributes of the Value in separate columns of the
row where its parent Entity is stored
❏ Value attributes are denormalized into their parent Entity’s table row,
there is no need for the database to use joins to retrieve even a
deeply nested Value instance

14. ORM and Many Values Serialized into a Single Column
❏ Mapping a collection of many Value Objects into a relational
database using an ORM
❏ To serialize the entire collection of objects into a textual
representation and persist the representation into a single column

15. ORM and Many Values Backed by a Database Entity
❏ To treat the Value type as an entity in the data model

16. ORM and Many Values Backed by a Database Entity

17. ORM and Many Values Backed by a Join Table
❏ To persist the collection Value elements to a dedicated table with the
parent Entity domain object’s database identity as a foreign key

18. WorkShop
1. 系統有四個角色 Manager/Operator/Partner/Engineer
2. 會員登入 輸入Account/Password來驗證身份
3. 玩家資料 可以輸入MemberCode或PartnerCode來查詢玩家資料
- 只有Partner不需要輸入PartnerCode 但是只能查到自己玩家的資料
- 只有Manager/Operator/Partner 可以調整玩家錢包的餘額
- 畫面上會呈現MemberCode/PartnerCode/錢包餘額
4. 玩家下注資料 可以輸入MemberCode或PartnerCode或日期區間來查詢玩家下注資料
- 只有Partner不需要輸入PartnerCode 但是只能查到自己玩家的資料
- 畫面上會呈現MemberCode/PartnerCode/下注金額/下注時間/結果(輸或贏或是未有
結果)

19. Reference
❏ Implementing domain driven design