题解 | 电商平台想要了解不同商品在不同月份的销售趋势

select
    p.product_id,
    product_name,
    sum(quantity) as total_sales,
    max(quantity) as max_monthly_sales,
    min(quantity) as min_monthly_sales,
    cast(avg(quantity) as signed) as avg_monthly_sales
from
    products_underline p
    join sales_underline s on p.product_id = s.product_id
where
    sale_month between '2024-01' and '2024-06'
group by
    p.product_id
order by
    p.product_id asc;

很简单，合并两个表，取出sale_month between '2024-01' and '2024-06'的记录，然后group by 商品id，获得合计，最大，最小和平均。