아이템 데이터베이스 구조

erDiagram Items ||--o{ ItemInstances : "has" Items ||--o{ ItemProperties : "has" Items ||--o{ ItemEffects : "has" Items }|--|| ItemTypes : "belongs_to" Items }|--|| ItemRarities : "has" ItemSets ||--|{ Items : "contains" ItemInstances }|--|| Players : "owned_by" ItemInstances ||--o{ ItemModifiers : "has" Items { string id PK string name string description int type_id FK int rarity_id FK int level string icon_url timestamp created_at timestamp updated_at int version } ItemInstances { string id PK string item_id FK string player_id FK int quantity int durability boolean is_bound timestamp acquired_at timestamp expires_at } ItemProperties { string id PK string item_id FK string property_key string property_value string property_type } ItemEffects { string id PK string item_id FK string effect_type float effect_value int duration float trigger_chance } ItemTypes { int id PK string name string category boolean stackable int max_stack } ItemRarities { int id PK string name string color float stat_multiplier int max_modifiers } ItemSets { string id PK string name string description int required_pieces } ItemModifiers { string id PK string instance_id FK string modifier_type float modifier_value timestamp expires_at } Players { string id PK string name int level timestamp created_at timestamp last_login }