erDiagram
    Venue ||--|{ Area : has
    Venue {
        string title
        int parent_id
    }
    Venue ||--O{ User : has  
    Venue ||--o{ Purchase_order : has
    Purchase_order ||--o{ Purchase_order_line : has
    Venue ||--o{ Draft_invoice : has
    Venue ||--o{ Pos_data : has
    Draft_invoice ||--o{ Draft_invoice_line : has
    Draft_invoice ||--o{ Draft_invoice_extra_line : has
    Venue ||--o{ Movement : has
    Movement ||--o{ Movement_line : has
    Movement ||--o{ Movement_extra_line : has
    Venue ||--o{ Inventory : has
    Inventory ||--|{ Inventory_area : has
    Inventory_area ||--o{ Inventory_areas_measurement : has
    Venue ||--o{ Area : has

---