erDiagram

    users {
        id serial PK "not null"
        phone varchar "not null, unique"
        email varchar "not null, unique"
        first_name varchar "not null"
        last_name varchar "not null"
        password_hash varchar "not null"
        password_salt varchar "not null"
        group_id integer FK "not null"
        created_at timestamp "not null"
        updated_at timestamp "not null"
    }
    groups {
        id serial PK "not null"
        name varchar "not null"
        key varchar "not null"
        created_at timestamp "not null"
        updated_at timestamp "not null"
    }
    driver_details {
        id serial PK "not null"
        driverLicenseNumber varchar "not null, unique"
        user_id integer FK "not null"
        business_id integer FK "not null"
        created_at timestamp "not null"
        updated_at timestamp "not null"
    }
    users_trucks {
        id serial PK "not null"
        user_id integer FK "not null"
        truck_id integer FK "not null"
    }
    trucks {
        id serial PK "not null"
        manufacturer varchar "not null"
        capacity integer "not null"
        price_per_km real "not null"
        license_plate_number varchar "not null"
        year integer "not null"
        tow_type varchar "not null"
        business_id integer FK "not null"
        created_at timestamp "not null"
        updated_at timestamp "not null"
        business_id integer FK "not null"
    }
    business_details {
        id serial PK "not null"
        company_name varchar "not null, unique"
        tax_number varchar "not null, unique"
        owner_id integer FK "not null"
        created_at timestamp "not null"
        updated_at timestamp "not null"
    }
    orders {
        id serial PK "not null"
        price integer "not null"
        scheduled_time timestamp "not null"
        start_point varchar "not null"
        end_point varchar "not null"
        status enum "not null"
        user_id integer FK "nullable"
        business_id integer FK "nullable"
        shift_id integer FK "nullable"
        customer_name varchar "nullable"
        customer_phone varchar "nullable"
        cars_qty integer "not null"
        created_at timestamp "not null"
        updated_at timestamp "not null"
    }
    files {
      id serial PK "not null"
      key varchar "not null, unique"
      name varchar "not null"
      content_type varchar "not null"
      created_at timestamp "not null"
      updated_at timestamp "not null"
    }
    shifts {
        id serial PK "not null"
        start_date timestamp "not null"
        end_date timestamp "nullable"
        driver_id integer FK "not null"
        truck_id integer FK "not null"
        created_at timestamp "not null"
        updated_at timestamp "not null"
        deleted_at timestamp "nullable"
    }
    users_trucks one or many -- one trucks: "users_trucks(truck_id) belongs to trucks(id)"
    users_trucks one or many -- one users: "users_trucks(user_id) belongs to users(id)"
    users one or many -- one groups: "users(group_id) belongs to groups(id)"
    business_details zero or one -- one users: "business_details(owner_id) belongs to users(id)"
    driver_details zero or one -- one users: "driver_details(user_id) belongs to users(id)"
    trucks one or many -- one business_details: "trucks(business_id) belongs to business_details(id)"
    driver_details one or many -- one business_details: "driver_details(business_id) belongs to business_details(id)"
    users one -- zero or many orders: "users(id) has orders(user_id)"
    users one -- zero or many orders: "users(id) has orders(user_id)"
    business_details one -- zero or many orders: "business_details(id) has orders(business_id)"
    shifts one -- zero or many orders: "shifts(id) has orders(shift_id)"
    users zero or one -- one or many shifts: "users(id) has shifts(driver_id)"
    trucks one -- zero or many shifts: "shifts(truck_id) has trucks(id)"