49 - 列出指定时间段内所有的下单产品

-- 指定2020年2月的方法
-- (1) order_date between '2020-02-01' and '2020-02-29'  
-- (2) order_date like '2020-02%'  
-- (3) DATE_FORMAT(order_date, "%Y-%m") = "2020-02"   
-- (4) LEFT(order_date, 7) 或 substr(1, 7)

select
    p.product_name,sum(unit) unit
from
    Orders o left join Products p on p.product_id=o.product_id
where
    o.order_date like '%2020-02%'
group by
    o.product_id
having
    sum(unit)>=100