db.md

DB Design

Access Pattern

1. fetchActiveLessonRoomByUid
   1. LINE ユーザーからのリクエストに含まれる UID から、進行中のレッスンルーム ID を 1 件取得する
2. putLessonRoom
   1. 新しいレッスンルームを 1 件作成する
3. fetchConversationsByLessonRoomId
   1. レッスンルーム ID をもとに会話履歴を全件取得する
   2. ソート順は、送信日の降順 1 . putLessonRoom
   3. レッスンルーム ID をもとにレッスンルームを「終了」に変更する

ER Diagrams

erDiagram
  user {
    string uid PK
  }

  lesson_room {
    uuid room_id PK "検索条件"
    string uid FK "検索条件"
    string status
    timestamp created_at
  }
  conversation {
    uuid room_id "検索条件"
    timestamp sent_at "ソート条件"
    string speaker "検索条件"
    string message
  }

  user ||--}o lesson_room: "attend multiple lessons"

  lesson_room ||--o{ conversation: "have conversations"

Loading

DynamoDB Schema

SmallGPTalk Table

	PrimaryKey		Attributes
Record Type	PK	SK
lesson_room (type)	room_id [LESSON#uuid]	uid [USER#string]	status [string]	created_at [number]
lesson_room (example)	LESSON#fdba3e0a-9a...	USER#4fab7256-ac..	IN_PROGGRESS	1677885697470
conversation (type)	room_id [LESSON#uuid]	sent_at [SENT_AT#number]	sender [string]	message [string]
conversation (example)	LESSON#fdba3e0a-9a...	SENT_AT#1677885697470	user	Hello!!!

Indecies

Primary Key

Keys	Attribute Name
Partition Key	PK
Sort Key	SK

GSI1

For the fetchLessonRoomByUid usecase.

Keys	Attribute Name
Partition Key	SK (USERS#{string})
Sort Key	created_at