威力全方位智慧健身房系統

erDiagram users { bigint id PK varchar email UK varchar role varchar pwd_hash int status datetime created_at } trainer_schedules { bigint id PK bigint trainer_id FK date schedule_date varchar schedule_time bit is_available } reservations { bigint id PK bigint member_id FK bigint trainer_id FK date reservation_date varchar reservation_time varchar check_in_key datetime check_in_time varchar status } products { bigint id PK varchar type nvarchar name decimal price bigint stock int version int status } cart_items { bigint id PK bigint user_id FK bigint product_id FK bigint quantity } orders { bigint id PK bigint user_id FK decimal total_amount varchar merchant_trade_no UK varchar status datetime created_at } order_items { bigint id PK bigint order_id FK bigint product_id FK decimal price_at_buy bigint quantity } inventory_logs { bigint id PK bigint product_id FK varchar change_type bigint quantity } chat_messages { bigint id PK bigint sender_id FK bigint receiver_id FK nvarchar message_content datetime created_at } comments { bigint id PK bigint user_id FK bigint product_id FK bigint order_id FK int rating nvarchar ai_sentiment_label } users ||--o{ trainer_schedules : "教練排班" users ||--o{ reservations : "預約 (member+trainer)" users ||--o{ orders : "下訂單" users ||--o{ cart_items : "購物車" users ||--o{ chat_messages : "通訊 (sender+receiver)" users ||--o{ comments : "發表評論" products ||--o{ cart_items : "加入購物車" products ||--o{ order_items : "訂單明細" products ||--o{ inventory_logs : "庫存異動" products ||--o{ comments : "被評論" orders ||--o{ order_items : "含明細 (Cascade)" orders ||--o{ comments : "關聯評論"