Thế giới của JOINS

SELECT COUNT(o.order_id) AS total_orders,
        AVG(p.price) AS average_price,
        -- Calculate total revenue
        ___ AS total_revenue	
FROM orders AS o
LEFT JOIN order_details AS od
ON o.order_id = od.order_id
-- Use an appropriate JOIN with the pizzas table
___ AS p
ON od.pizza_id = p.pizza_id