Inventory ER Diagram (Mermaid)

erDiagram
  WAREHOUSE ||--o{ STOCK : holds
  PRODUCT ||--o{ STOCK : "stored as"
  SUPPLIER ||--o{ PRODUCT : supplies
  WAREHOUSE {
    int id PK
    string location
  }
  PRODUCT {
    int id PK
    string sku
    int supplier_id FK
  }
  STOCK {
    int warehouse_id FK
    int product_id FK
    int quantity
  }
  SUPPLIER {
    int id PK
    string name
  }