题解 | #从 Pro#
从 Products 表中检索所有的产品名称以及对应的销售总数
https://www.nowcoder.com/practice/2b289b78de1546f38fd24e17e56f1bec
select
prod_name,
quant_sold
from
Products pd
left join (select prod_id,sum(quantity) quant_sold from OrderItems
group by prod_id) t on t.prod_id = pd.prod_id;
方式二：
select prod_name,
(select sum(quantity) from OrderItems a group by prod_id having a.prod_id=b.prod_id)
quant_sold from Products b ;
