题解 | 了解 2023 年全年所有商品的盈利情况

select
    product_id,
    sum((unit_price - purchase_price) * quantity) as total_profit,
    round(
        100 * (avg(unit_price) - purchase_price) / purchase_price,
        2
    ) as profit_margin
from
    purchase_prices
    join sales_orders using (product_id)
where
    order_date between '2023-01-01' and '2023-12-31'
group by
    product_id
order by
    product_id